Grundfos Alpha 3 Pump Settings for Hydronic Balancing

[hallra]

Hi Forum,

I am attempting to manually balance the radiators in my house, to get an average of 11c drop between Flow and Return on each radiator.

I have set the boiler temprature to 65c.

With the Grundfos Alpha 3, it has several control modes, with each mode needing a value set:

Constant Pressure requires a setpoint in metres.
Proportional Pressure requires a setpoint in metres.
Constant Curve requires a setpoint percentage.
Radiator Mode (Auto Adapt)

- Most manual balancing advice out there, states to start with a run speed of II, then change it if the 11c balancing can't be achieved.

With this option not avaiable, would running a constant curve (which I believe is a constant speed) at say 65%, be the way to go or I should be using something else?


All advice would be much appreciated


Thanks

 

[John.g]

Hi Forum,

I am attempting to manually balance the radiators in my house, to get an average of 11c drop between Flow and Return on each radiator.

I have set the boiler temprature to 65c.

With the Grundfos Alpha 3, it has several control modes, with each mode needing a value set:

Constant Pressure requires a setpoint in metres.
Proportional Pressure requires a setpoint in metres.
Constant Curve requires a setpoint percentage.
Radiator Mode (Auto Adapt)

- Most manual balancing advice out there, states to start with a run speed of II, then change it if the 11c balancing can't be achieved.

With this option not avaiable, would running a constant curve (which I believe is a constant speed) at say 65%, be the way to go or I should be using something else?


All advice would be much appreciated


Thanks

Which model (head) have you got is it the 4M or the 6M or the 8M, you should see 40 or 60 or 80 at the end of the pump label, something like 25-40 etc. Also what is the boiler output (condensing or non condensing?) and number of rads and have you got zoning or TRVs or whatever on your system?.

 

[hallra]

Hi John,

It’s the Alpha 3 Model B 15-50/60, so 6M.

The boiler is a Glowworm Ultracon 24HXI, the manual says condensing boiler on its cover.

The piping is a S Plan layout.

There are 8 steel panel Rads and two towel rails.

The house is microbore throughout.

It is piped for one zone, 8 Rads have Smart TRVs and 2 have manual TRVS.


Let me know if other information is needed?


Regards

Richard

 

[John.g]

Hi John,

It’s the Alpha 3 Model B 15-50/60, so 6M.

The boiler is a Glowworm Ultracon 24HXI, the manual says condensing boiler on its cover.

The piping is a S Plan layout.

There are 8 steel panel Rads and two towel rails.

The house is microbore throughout.

It is piped for one zone, 8 Rads have Smart TRVs and 2 have manual TRVS.


Let me know if other information is needed?


Regards

Richard

 

[John.g]

OK, thanks. As you have a condensing boiler set to 65C then I would suggest aiming for a rad deltaT of 15 to 20C to get the maximum condensing effect as long as it doesn't affect your rad outputs too much.
I would suggest a first setting of PP3 which is 2.25 to 4.3M head, then read off and write down the power consumption, then change to CP2 which is 3.2M constant pressure and again read off and write down the power consumption, then change to Auto Adapt (if available on that pump) and again read off and write down the power consumption. Try and do the initial readings with all rads and hot water cylinder calling for full heat, if your system is up and running just now I would still do the above. I have a somewhat similar set up to your one with a different pump (no auto adapt) and on a PP setting of 2.0 to 4.0M the power consumption varies between 20/22W and 12/14W when the TRV's are throttled/throttling down, the (20 kw, non condensing) boiler deltaT is ~ 22/24C.

 

[hallra]

Hi John,

thanks for the infomation, however, I'm not sure how to set PP3 and CP2 on the Alhpa 3, as these settings are not available and it's where I get stuck.
- I think PP3/CP2 are settings on Aplha 2.
- No Information in the Alpha 3 manual on how to do it.

For propotional pressure and constant pressure, there is no range, just a single setpoint in 0.1m increments.
- do you know how I can mimic the PP3 & CP2 seetings you suggest?

From what I understand, AutoAdapt automatically adjusts it own PP/CP setpoints, however, when I've used Auto Adapt, the system struggles to heat up the radiators and rooms can't retain heat.

Finally, with doing as you advise, once I have all these readings, how do I best decide what to stick with, what to use to get the Delta T close to 15/20c.

So for all the questions, but the manual is hopeless and Grundfos support more so.

 

[John.g]

Hi John,

thanks for the infomation, however, I'm not sure how to set PP3 and CP2 on the Alhpa 3, as these settings are not available and it's where I get stuck.
- I think PP3/CP2 are settings on Aplha 2.
- No Information in the Alpha 3 manual on how to do it.

For propotional pressure and constant pressure, there is no range, just a single setpoint in 0.1m increments.
- do you know how I can mimic the PP3 & CP2 seetings you suggest?

From what I understand, AutoAdapt automatically adjusts it own PP/CP setpoints, however, when I've used Auto Adapt, the system struggles to heat up the radiators and rooms can't retain heat.

Finally, with doing as you advise, once I have all these readings, how do I best decide what to stick with, what to use to get the Delta T close to 15/20c.

So for all the questions, but the manual is hopeless and Grundfos support more so.

You say "For propotional pressure and constant pressure, there is no range, just a single setpoint in 0.1m increments." can I take it then that you can select proportional pressure (PP control) and incrementally increase it? if so just select it and increase it to 4.0 or a little higher say 4.3.
What setting are you using now? and what is the power consumption??. I thought that the Auto Adapt might be a bit weak alright, can you remember what was its power consumption?.

Can you please post a link to your instruction manual, thanks.

Edit: Is this the pump & manual (attached).?
Sorry had wrong file...is this it, I think so.

Edit again: reading this file it would appear that you need the Grundfos GO App??? and the pump comes in the default mode of Auto Adapt, have you got this App? if not what, if any, settings can you change.?

You might be able to download the app and configure it from your laptop....have a read of this.
A New Grundfos Pump Range is Circulating - Plumbase Blog

 

[hallra]

Hi John,

Got to collect the Mrs and sort her out...

I’ll gather the information and come back to you later on this evening.

Much Appreciated

 

[hallra]

Hi John,

Yes, I have the Grundfos Go Remote app on the phone, it configured/controls the Alpha 3 pump.

It uses Bluetooth to talk to the pump.

It allows the control mode, operating mode & setppoint to be set

 

[hallra]

I’ve opened all smart/manual TRVs to max so constantly calling for heat.

This is auto adapt:

 

[hallra]

Proportional Pressure at 4.3M:

 

[hallra]

Constant Pressure at 3m (default):

 

[hallra]

The app can also produce this report. (attached)

I can create one for Constant pressure and Auto Adapt, if the contents are useful?

 

[hallra]

Alpha 3 document.

 

[John.g]

The app can also produce this report. (attached)

I can create one for Constant pressure and Auto Adapt, if the contents are useful?

Thanks for that, now, the reading of 0.4 M3/hr (6.7 LPM) @ 3M on CP, my system has almost double that flow rate @ 3M ie ~ 12 LPM so it would appear that you have a lot of resistance to flow, possibly in part due to the micro bore piping. The only way, without major piping surgery, to get the flow rate up is to increase the pump head, but because head is proportional the square of the flow then if you require say a minimum of 12 LPM with everything opened up you would need a pump head of, (12.0/6.7)^2, or 9.6M,
I would set the pump to its maximum possible head in CP mode now and see what the resultant flow rate is and the power consumption.
I think you can set the max flow on that app as well in the different modes so ensure that it is not < 1.5 M3/hr.

 

[hallra]

Hi,

This is the status with Max CP.

 

[John.g]

Hi,

This is the status with Max CP.

View attachment 36987

Its all adding up so can you now change to the max constant curve (fixed speed 3 in old terms) and see what the result is, thanks

 

[hallra]

Now I have very noisy radiator valves.

Are you saying that that pipework is badly undersized?
- This is a new build and if there is a problem with pipework, it should be covered by LABC warranty... you thoughts will be very useful...

That aside, should I be opening up the lockshields tomorrow to see if I can get a delta T of 15-20

 

[John.g]

Now I have very noisy radiator valves.

Are you saying that that pipework is badly undersized?
- This is a new build and if there is a problem with pipework, it should be covered by LABC warranty... you thoughts will be very useful...

That aside, should I be opening up the lockshields tomorrow to see if I can get a delta T of 15-20

Oh yes, I should have ephpasised that from the start, open up everything on every rad fully, locks shields included and start from scratch again, if the main supply & return headers are even 3/4 ins then as long as the rads arn,t daisy chained in micro bore then the head losses should,nt be excessively high, when you start again with everything opened up you can then see if there is something wrong.

What setting were you on before you started throttling the lock shields?

The ~ way that I calculate the delta T required is : in your case, 8 rads @ 2 kw each = 16 kw, deltaT required 20C, minimum total flow rate required is then, 16*860/20/60, or 11.5 LPM or 15.3 LPM at a deltaT of 15C.

 

[hallra]

Max Constant Curve:

 

[John.g]

Max Constant Curve:

View attachment 36988

Is that now with everything opened up, if so then IMO 10 LPM requiring a 6M head would indicate something not right.

Is the cylinder coil opened up as well for these tests.

 

[hallra]

When I started to balance manually today, I had it on constant curve with a setppoint of 65%, it wasn’t working well....

Yesterday, I had made use of the Grundfos hydronic balancing application, GO Balance, but once the software guided balancing was complete and pump switched into Auto Adapt mode, the radiators weren’t heating correctly... and one was stone cold...

The Go Balance Application It requires a series of user inputs, which some I had to guesstimate and some it would refuse to accept as it would predict that the required heat output for a given room was not achievable... - So I ended up lowering figures until it would accept them... which then probably as a consequence messed up the balancing...

 

[hallra]

Is that now with everything opened up, if so then IMO 10 LPM requiring a 6M head would indicate something not right.

Is the cylinder coil opened up as well for these tests.

I believe everythging is open, all TRVs are.

Bypass is closed.

The hot water is off.

 

[John.g]

When I started to balance manually today, I had it on constant curve with a setppoint of 65%, it wasn’t working well..

Yesterday, I had made use of the Grundfos hydronic balancing application, GO Balance, but once the software guided balancing was complete and pump switched into Auto Adapt mode, the radiators weren’t heating correctly... and one was stone cold...

The Go Balance Application It requires a series of user inputs, which some I had to guesstimate and some it would refuse to accept as it would predict that the required heat output for a given room was not achievable... - So I ended up lowering figures until it would accept them... which then probably as a consequence messed up the balancing...

Ok, well to recap, before any balancing is done I think you have to be absolutely certain that your system has been plumbed properly. The pump head and flow rate will tell a lot as it has done so except that the software is fooling everyone then it would appear that your system has a very high resistance.
The cylinder coil itself, even IF all the rads are shut off should flow ~ 6 to 8 LPm at a 3M head as it is basically a 3/4 ins by pass.

 

[John.g]

I believe everythging is open, all TRVs are.

Bypass is closed.

The hot water is off.

Should have seen that earlier, if you care to do one more test open the coil MV, c/o to CP setting 3M and see what the result is as there is hardly any restrictions in the coil.

I believe everythging is open, all TRVs are.

Bypass is closed.

The hot water is off.

 

[hallra]

Let me shut off all rads and run with hot water on, to get you a cylinder coil reading...

I’ll get a reading at Max CP & Max CC, anything else you need?

 

[hallra]

Ok, you beat me to it...

Trying to get the acronyms

Is that;

Turn on Hot Water only, to open coil, set pump to constant Pressure with set point 3m?

 

[John.g]

Ok, you beat me to it...

Trying to get the acronyms

Is that;

Turn on Hot Water only, to open coil, set pump to constant Pressure with set point 3m?

Ok, you beat me to it...

Trying to get the acronyms

Is that;

Turn on Hot Water only, to open coil, set pump to constant Pressure with set point 3m?

No, both HW & CH and set pump to CP 3M.
If you like you can then do it on HW only on CP 3M.

 

[hallra]

This is just Hot Water on and CP 3m:

 

[John.g]

This is just Hot Water on and CP 3m:

View attachment 36990

OK thanks, last test with HW&CH @ CP 3M

 

[hallra]

Here is the status will all TRVs open, heating on and hot water on:

 

[hallra]

I’ve just noticed that the Smart TRV app is showing an error, might mean that one of the TRV maybe malfunctioning... can’t tell from the app would need to remove all the Smart TRVs to ensure it’s not causing an issue...
- That would have to wait till tomorrow to test as the wife is sleeping.

It didn’t have an error earlier on during our tests...

 

[John.g]

I’ve just noticed that the Smart TRV app is showing an error, might mean that one of the TRV maybe malfunctioning... can’t tell from the app would need to remove all the Smart TRVs to ensure it’s not causing an issue...
- That would have to wait till tomorrow to test as the wife is sleeping.

It didn’t have an error earlier on during our tests...

Ok thanks, thats grand for the night, it may be well worth doing what you suggest to rule out any restrictions due to valve throttling or whatever.

 

[hallra]

I'll do tomorrow and let you know.

Cheers for all the help, speak tomorrow

 

[John.g]

I’ve just noticed that the Smart TRV app is showing an error, might mean that one of the TRV maybe malfunctioning... can’t tell from the app would need to remove all the Smart TRVs to ensure it’s not causing an issue...
- That would have to wait till tomorrow to test as the wife is sleeping.

It didn’t have an error earlier on during our tests...

Its interesting to see that there is virtually no difference in flow rates, power etc between HW only and HW+Heating, 1 watt and 10 rpm, I noticed the same with my system last year, no change in power under those same conditions, I don't have the RPM & Flow rate display on my pump, only power.

Re noisy operation on 6M setting, I tried this setting in my system this morning and I couldn't detect any noise even when I throttled in various TRVs etc, I assume that your TRVs are bi directional of if not, are fitted correctly? as I read somewhere that they can be noisy under certain conditions, Its just possible but unlikely that there is air in your system which would certainly lead to noisy operation when combined with a high head. Have you got a open or sealed system? with AAVs.
I said earlier that I too have micro bore but apart from the 2X 3/4 ins headers all the radiator tails are either 1/2" copper or Q.plex with a ID of 11 mm, micro bore may be 8mm ID, I hope not less. I will post a pipe friction loss link where you can calculate the big effect on head with reduced ID, I normally use 1 LPM for each kw of radiator output.
Re "the bypass is closed", is this a ABV (automatic by pass valve) and what is its setting?, they normally range from 0.1 bar to 0.5 bar.
I've nothing more to offer at the moment.

Pipe friction loss link.
friction_loss

 

[hallra]

Hi John,

Sorry it has taken time to come back to you today, i'm managing a long term health condition/disability, that affects me greatly earlier in the day.

I've tried to put as much information here as possible to give you where I am at, if you lived nearby, I am West London, I'd gladly pay you to come and diagnose what is wrong with my heating.

I really appreciate you taking time to help me, if you feel at anytime I need to call someone in, please let me know, just it is a jungle out there and it is near impossible to find a decent engineer who is interested in working on these types of issues.


Getting back to answering your questions:


I've just had the TRV bodies replaced, the steel rads have Honeywell Valencia TRVs VHL120 15mm:

https://heatingcontrols.honeywellhome.com/Documents/All/pdf/Valencia Installation Guide.pdf

- I bought these replacement TRV bodies as they have balancing inserts to allow manual balancing, but after talking to Honeywell, I abandend using them and have set the inserts to 14, which is fully open and switched to using the lockshields to control flow...

The towel rails have:

https://www.amazon.co.uk/Realm-Corner-TRV-Chrome-Thermostatic/dp/B00HCL4FYW

The steel rads pipework is 10mm Microbore into a 10mm - 15mm angle, into the 15mm TRV valve.

The towel rails have 15mm copper pipework.

I note at around 50cm from boiler 22mm copper pipe is connected with right angle pushfit into 22mm plastic pipe.

All TRVs are bi directional and mainly on the flow pipe.
The lockshields are bidirectional.
The Two way valves are the correct way around.
The pump is the correct way around.
On the flow from the boiler is a Air Seporator.
On the Return to the boiler is a Adey Magnaclean Professional 2.

It is a unvented CH system with system pressure set to 1.6bar

I has one AAV and one manual air vent, in the cupboard with expansion tanks, cylinder, two way valves, pump.


Automatic Bypass Valve
---------------------------

The story here is that I switched the ABV to a manual gate valve after Grundfos support told me that I couldn't use their 'Go Balance' balancing software and the Auto Adapt pump control with an ABV...
- I had a big agument with their head of support over this...

Anyway, after unsuccessfully using their balancing software and unsuccessfully manually balancing, I put the ABV back and have it in series with a gate valve after it...
- There is actually some literature out there from Grundfos to do this if a ABV is required with the Alpha pumps...

Anyway, going back to your question about ABV...

I can't tell what it is set to as the numbering has rubbed off, it appears to be around 0.1 - 0.2 at a guess, however, I haven't heard it open once and I've played around with it up and down the complete length of the ABV range...
- I'm not sure if I need to replace the ABV if it is not working... However, the boiler isn't complaining, even when I ensure it is completely closed by closing the Gate Valve.


History
---------

Just a bit of background for you...

If you look at my posted over the last 3-4 months, you will see I have had no end of problems and components failing on the CH, all have which have led me to this point.

I have had the expansion tank fail.
Pressure Guage fail.
I had the Automatic Air Vent fail twice.
I've had trapped air and noise that I only succeeded in getting rid of once I put an air seporator in.
I've had the pump replaced.
I've had the pump connectors leak.
I've played with the system pressure.
I've had black water in the radiators, I have flushed all rads with a hose to get rid of it.
I've run Adey cleaner through the system for 3 weeks and again for another week.
I added the Magnaclean Pro 2.

I also installed the TADO Smart TRVs and Thermostat.

As you see I've done a ton of stuff and still have issues.

I'm only an ametuer DIY guy with a background in software engineering.

 

[hallra]

I have now gone around and opened up all lockshields fully, taken off all TRVs, I have switched on the CH and HW.

The bypass is set as described previously.

Here are the status reports from the app:

- The Max Estimated Flow rate has increased to 0.9 m3/h
- When the heating or HW circuit is closed the max drops to 0.8 m3/h

CC Max

PP Max

CP Max

CP 3M

PP 3M

Auto Adapt

 

[John.g]

I have now gone around and opened up all lockshields fully, taken off all TRVs, I have switched on the CH and HW.

The bypass is set as described previously.

Here are the status reports from the app:

- The Max Estimated Flow rate has increased to 0.9 m3/h
- When the heating or HW circuit is closed the max drops to 0.8 m3/h

CC Max

View attachment 36997

PP Max

View attachment 36998

CP Max

View attachment 36999
CP 3M

View attachment 37000
PP 3M

View attachment 37001

Auto Adapt

View attachment 37002

Thanks for that very detailed post, I would have no problem in calling to you FOC but I am a long way from "London Town", in fact from a neighbouring country.
I am not in the "plumbing business" but (now long semi-retired) spent 15 years as a marine engineer and over 30 years running the Utilities Department of a large pharmaceutical company and have lots and lots of experience in all sorts of industrial pumps & pumping systems, high pressure steam boilers, combined heat and power systems, diesel generator, steam turbine & gas turbine generating sets etc, more importantly, I have always had and have a avid interest in all these things, big or small. OK then back to business.

Your system is now beginning to look a bit better, just take the CP max numbers of 0.9 ms/hr (15 LPM) @ 5.1 M. or 0.7 m3/hr (11.7 LPM @ 3M. (close to my flow rate)

IF you have no noise issues at this setting would suggest leaving it like this and take a bit of time to see how all the rads are performing before doing any balancing (if, in fact required). If you do have to do some balancing or you decide to re instate or install new TRVs anf IF you then get some noise when they are throttling down then you could consider changing to the max PP mode as the pump will then modulate down and reduce the head (and noise) but should still give reasonable flow rates.

AAV: I would suggest fitting a ball (lever) isolating valve before this to enable change out or isolation, as you probably know these can have a habit of spitting out a bit so once you have got rid of the main vol of air I would just close the little screw down cap that is (or should be) fitted to the air release nozzle and just open it occasionally.

ABV: The reason for not using it in PP mode or Auto Adapt (which is also PP mode) is as follows.
The main purpose of the ABV is to supply a flow through the boiler to cool down the heat exchanger when all the zone valves, if fitted, close, the boiler controls tell the pump to continue running for a few minutes or it may look at the flow temperature and then shut down the pump. On CC control, when the zone valves shut down, the pump pressure will rise so the ABV can be set up to be shut under all normal running conditions and only open on boiler shutdown. CP control is a little different in that the pressure is (obviously) constant so the advice there is to fit a manual by pass to give minimum by pass flow at all times.
On PP mode, as soon as the zone valves shut the pump will ramp down to its minimum head of 1/2 the max PP head, if the max PP head is 5M then at zero flow the head will be 2.5M so if you set the ABV to open at 2.5M, the bypass flow will be excessive under normal running conditions. Thats why Grundfos I would think advise not to run on Auto Adapt or PP mode where pump over run is required to cool down the heat exchanger.
If you do re instate the TRV,s then I would advise leaving one rad without a TRV, this will then act as a permanent by pass, I think I saw somewhere that some boiler manufacturers recommend the chosen rad be 10% of the boiler output so a 25 kw boiler would require a 2.5 kw rad but IMO any reasonably sized rad will do the job. By doing this you can run in any mode you want.

The last thing is the deltaT through your rads, I don't know what the individual rad outputs are but with a flowrate of 15 LPM then each rad is getting a average of 1.9 LPM, a 2 kw rad will then have a deltaT of, 2*860/1.9/60, or 15C and pro rata. If you can get hold of a temperature (infra red) scanner you can then do a bit of balancing. If they are all a little on the low side then you can always reduce the CP or PP head a little which will reduce the flow rate and increase the deltaT.

That's about it for the moment, let us know what the max head is without incurring noise problems.

Forgot to ask if you have or do inspect that magnaclean filter occasionally to ensure no restriction to flow.

I was just reading your tales of woe in the other posts including expansion valve failure and air ingress. I assume that the circ pump is on the flow side of the boiler, when you get the time, confirm this, and more importantly where the expansion vessel is teed into the system.

 

[hallra]

Hi John,

many thanks for your detailed post in return.

I had overdone things yesterday and the day before, playing with the heating system, as a consequence I wasn't able to sum up the strength to reply to you last night, so my apologies.

I saw from your profile that you lived in Cork, hence I realised that asking you to come and look at my heating might be a bit problematic )
- I once went to a wedding in Cork, lovely place to visit... Spent the whole wedding night woohing some lass from America, early hours down by the harbour, getting locked out of my digs, somehow ended up in 'her' room.... now that holds good memories

You have an interesting background, mine is 30 years in software development/engineering/design/etc both as an employee and running my own one man band. Interestingly, I did 5 years contract work at GSK. Right now, I'm an employee for an Investment Bank, however due to long term Illness/disability I'm unable to work.

So, though i'm not a plumber in any shape or form, I have a fairly good understanding of how things work and a high capacity to learn quickly, smartly and most importantly correctly.

- What I find challenging, like in most technical industries (IT is the worst), is that accurate/useful information is hard to get, many people who are experts, understand day to day practical things but don't have the capacity/ability to share their knowledge to educate others, with many hiding behind the 'oh you will not be able to understand mantra', when it is in fact they just don't have the knowledge themselves.

- Technical support helplines are a hit and miss affair, Grundfos is a typical prime example of a particularly bad one, when I've called them for advice on their own products they hide behind the 'unless you are a G3 Engineer/system designer' we aren't talking to you... or we don't give advice you will have to talk to your system designer...
Then even when I've escalated to their Head of Customer Support and clearly demonstrated my capabilities and that their software product has no documentation, is full of holes/bugs and is totally unusable... Their claim is it doesn't need documentation as any G3 Engineer can use it... Interesting that their product refers to terminology that doesn't appear anywhere on the entire internet...
- I may later, if you are willing, ask you some questions that may point some light on questions I have about this software...


Anyway, sorry to babble on, but it's always interesting to have a side conversation going on....


The noise comes about when throttling down the lockshields to restrict flow and then upping the pressure output of the pump to get enough flow around the system...
- I need to try running the pump in PP Max mode after balancing, to see if it solves the noise issue, I was using constant curve.

With all the lockshields fully open, the noise disappears, however as a consequence, some of the Rads, mainly the ones in the downstairs front room don't heat.

FYI, going back to the original reason for wanting to balance the system was:

1) Front Room, Bedroom 2, Ensuite Shower Room not able to heat up and maintain heat when outside temperature <5c.
- Doesn't help that New Build House has insulation issues. This is being worked on, but a major problem getting builder/warranty company to fix, but slowly getting there... (Working on this for 3yrs!)
2) Rads overheats easily.
3) TADO smart TRVs struggles with the issues above.
4) Boiler continuously short cycles.


Software Balancing
------------------

I would like to retry using the Grundfos 'Go Balance' software:


Theoretically, it should work well, it uses the pump's abilities to measure flow/pressure/etc to detect the heating system and radiator capabilities, together with user input to calculate heat loss... It will then guide the user to throttle each radiator to set a certain flow.
- However, when I've used this software, some inputs i've had to guess, which could be the reason that it hasn't worked well... - Some rads not heating well, always at least one cold... (The software gives a choice of running system in AutoAdapt or PP afterwards, I had always gone with AutoAdapt, which may have not helped..)

If you are, willing, I would like to run the user inputs past you, as you probably can come up with far better inputs to use... Let me know if it is ok to ask?


Manual Balancing
----------------

If in the end the software fails to get it right, I will then need to use manual balancing with a temperature gauge (I have an InfraRed Flur gun) - I did struggle to know what mode to run the pump in, to mimic Fix Run Speed 2, but I'm thinking CC set to a setpoint of 65%??


AAV
---

Yep, learnt my lesson previously on this one, I have the AAV closed after removing air from the filling process.
- It would be hard to fit a isolation valve, purely due to the AAV currently screwed into a bolt that has been solder into a Tee that itself is soldered into small very tight pipework, redoing the pipework would take major surgery and the other issue is I haven't taught myself how to solder (yet), so ideally I would be using compression components, which isn't ideal...

I haven't closed the Air Separator, should I?



ABV
---

I'm not actually sure if one is actually needed... It have never seen it open in AutoAdpat/PP modes and I have not had any issues with my boiler when the heating circuits and bypass are closed, even though the boiler manual states a bypass is required.
- Interestingly though, Glowworm support have told me that the boiler has no minimum flow requirements, which contridicts the manual.


Delta T through the Rads.
------------------------

Part of the exercise to gather information for the 'Go Balance' software, I have all the technical specs of each radiator and specifications of each room, plus me Infrared temperature gun.


Magnaclean
----------

I fitted it in December, checked in on Thursday, it was practically clean, a miniscule amount on it.
- Interestingly, when I put the ABV back on Thursday, the elbow I took off (which was put in its place when I took it out, had a bit of blackness settled in it. Guessing it had settled there due to the manual bypass being closed)


Pipework Layout
---------------

As far as I can tell the pump is on the flow side, certainly the flow pipe from the boiler heats first, the pump is before the 2 way valves to radiator/HW circuits.

I can't be 100% sure as pipework is hidden between boiler and airing cupboard that contains the pump, valves, expansion tank, HW cylinder.

Is there a sure way to tell??


Expansion Vessel position
-------------------------

The pipework to the expansion vessel comes off the return pipework back to the boiler.

I've attached a photo of the pipework, let me know if more photos are required.

Legend:

A - Return to boiler.
B - Flow from boiler.
C - Radiator return from downstairs and upstairs rads.
D - Flow to downstairs radiators.
E - Cold Water feed.
F - Hot water out of the cylinder.

Note:

The 2 way valves for downstairs and upstairs are wired together, I did this as TADO only works with one physical zone. - I may at a later date, re-pipe to only have one 2 way valve to control the radiator circuit.

The layout of return pipework from the radiators, HW cylinder and the bypass has always put a question mark in my head, as it doesn't look right, however, I don't know what a correct layout would look like... What do you think?



Right, I will stop for now, I think there is a mass of information for you to read and a ton of questions, I again thank you for helping me out, I hope this is all interesting for you.


Cheers!


Richard.


Ps, If you ever want to chat on the phone or switch to email, let me know.
Pps, I might struggle with the accent

 

[John.g]

Hi John,

many thanks for your detailed post in return.

I had overdone things yesterday and the day before, playing with the heating system, as a consequence I wasn't able to sum up the strength to reply to you last night, so my apologies.

I saw from your profile that you lived in Cork, hence I realised that asking you to come and look at my heating might be a bit problematic )
- I once went to a wedding in Cork, lovely place to visit... Spent the whole wedding night woohing some lass from America, early hours down by the harbour, getting locked out of my digs, somehow ended up in 'her' room.. now that holds good memories

You have an interesting background, mine is 30 years in software development/engineering/design/etc both as an employee and running my own one man band. Interestingly, I did 5 years contract work at GSK. Right now, I'm an employee for an Investment Bank, however due to long term Illness/disability I'm unable to work.

So, though i'm not a plumber in any shape or form, I have a fairly good understanding of how things work and a high capacity to learn quickly, smartly and most importantly correctly.

- What I find challenging, like in most technical industries (IT is the worst), is that accurate/useful information is hard to get, many people who are experts, understand day to day practical things but don't have the capacity/ability to share their knowledge to educate others, with many hiding behind the 'oh you will not be able to understand mantra', when it is in fact they just don't have the knowledge themselves.

- Technical support helplines are a hit and miss affair, Grundfos is a typical prime example of a particularly bad one, when I've called them for advice on their own products they hide behind the 'unless you are a G3 Engineer/system designer' we aren't talking to you... or we don't give advice you will have to talk to your system designer...
Then even when I've escalated to their Head of Customer Support and clearly demonstrated my capabilities and that their software product has no documentation, is full of holes/bugs and is totally unusable... Their claim is it doesn't need documentation as any G3 Engineer can use it... Interesting that their product refers to terminology that doesn't appear anywhere on the entire internet...
- I may later, if you are willing, ask you some questions that may point some light on questions I have about this software...


Anyway, sorry to babble on, but it's always interesting to have a side conversation going on..


The noise comes about when throttling down the lockshields to restrict flow and then upping the pressure output of the pump to get enough flow around the system...
- I need to try running the pump in PP Max mode after balancing, to see if it solves the noise issue, I was using constant curve.

With all the lockshields fully open, the noise disappears, however as a consequence, some of the Rads, mainly the ones in the downstairs front room don't heat.

FYI, going back to the original reason for wanting to balance the system was:

1) Front Room, Bedroom 2, Ensuite Shower Room not able to heat up and maintain heat when outside temperature <5c.
- Doesn't help that New Build House has insulation issues. This is being worked on, but a major problem getting builder/warranty company to fix, but slowly getting there... (Working on this for 3yrs!)
2) Rads overheats easily.
3) TADO smart TRVs struggles with the issues above.
4) Boiler continuously short cycles.


Software Balancing
------------------

I would like to retry using the Grundfos 'Go Balance' software:


Theoretically, it should work well, it uses the pump's abilities to measure flow/pressure/etc to detect the heating system and radiator capabilities, together with user input to calculate heat loss... It will then guide the user to throttle each radiator to set a certain flow.
- However, when I've used this software, some inputs i've had to guess, which could be the reason that it hasn't worked well... - Some rads not heating well, always at least one cold... (The software gives a choice of running system in AutoAdapt or PP afterwards, I had always gone with AutoAdapt, which may have not helped..)

If you are, willing, I would like to run the user inputs past you, as you probably can come up with far better inputs to use... Let me know if it is ok to ask?


Manual Balancing
----------------

If in the end the software fails to get it right, I will then need to use manual balancing with a temperature gauge (I have an InfraRed Flur gun) - I did struggle to know what mode to run the pump in, to mimic Fix Run Speed 2, but I'm thinking CC set to a setpoint of 65%??


AAV
---

Yep, learnt my lesson previously on this one, I have the AAV closed after removing air from the filling process.
- It would be hard to fit a isolation valve, purely due to the AAV currently screwed into a bolt that has been solder into a Tee that itself is soldered into small very tight pipework, redoing the pipework would take major surgery and the other issue is I haven't taught myself how to solder (yet), so ideally I would be using compression components, which isn't ideal...

I haven't closed the Air Separator, should I?



ABV
---

I'm not actually sure if one is actually needed... It have never seen it open in AutoAdpat/PP modes and I have not had any issues with my boiler when the heating circuits and bypass are closed, even though the boiler manual states a bypass is required.
- Interestingly though, Glowworm support have told me that the boiler has no minimum flow requirements, which contridicts the manual.


Delta T through the Rads.
------------------------

Part of the exercise to gather information for the 'Go Balance' software, I have all the technical specs of each radiator and specifications of each room, plus me Infrared temperature gun.


Magnaclean
----------

I fitted it in December, checked in on Thursday, it was practically clean, a miniscule amount on it.
- Interestingly, when I put the ABV back on Thursday, the elbow I took off (which was put in its place when I took it out, had a bit of blackness settled in it. Guessing it had settled there due to the manual bypass being closed)


Pipework Layout
---------------

As far as I can tell the pump is on the flow side, certainly the flow pipe from the boiler heats first, the pump is before the 2 way valves to radiator/HW circuits.

I can't be 100% sure as pipework is hidden between boiler and airing cupboard that contains the pump, valves, expansion tank, HW cylinder.

Is there a sure way to tell??


Expansion Vessel position
-------------------------

The pipework to the expansion vessel comes off the return pipework back to the boiler.

I've attached a photo of the pipework, let me know if more photos are required.

View attachment 37026
Legend:

A - Return to boiler.
B - Flow from boiler.
C - Radiator return from downstairs and upstairs rads.
D - Flow to downstairs radiators.
E - Cold Water feed.
F - Hot water out of the cylinder.

Note:

The 2 way valves for downstairs and upstairs are wired together, I did this as TADO only works with one physical zone. - I may at a later date, re-pipe to only have one 2 way valve to control the radiator circuit.

The layout of return pipework from the radiators, HW cylinder and the bypass has always put a question mark in my head, as it doesn't look right, however, I don't know what a correct layout would look like... What do you think?



Right, I will stop for now, I think there is a mass of information for you to read and a ton of questions, I again thank you for helping me out, I hope this is all interesting for you.


Cheers!


Richard.


Ps, If you ever want to chat on the phone or switch to email, let me know.
Pps, I might struggle with the accent

Thanks Richard,

Where to start?

It's very hard to tell from photo's etc the piping layout but any/most experienced plumbers should be able to check that out.

I think your first task should be to get rid of any remaining air before doing any form of balancing, either software or manually.
I have no problem in you forwarding any info re software balancing but I feel that there is something fundamentally wrong when both D/stairs & U/stairs don't heat together in some form or other.

On the Top Up system: are the isolating valves to the pressure reducing valve (PRV) open or shut?, I would shut them off if open and ensure that the expansion vessel pressure stays constant or within its normal rise and fall with cold/hot boiler to make sure that you havn,t got a leak somewhere in the system, the constant make up will then continuously release its oxygen and you will always have problems with air in the system apart from any corrosion problems.
You say that the U/stairs & D/stairs MVs are wired together, have you checked that they are both opening fully?.

With valves open to the top up system and AAV open and HW off:
I would shut off all the rads (one side only) and starting D/stairs, just open the first one ( pump on CP 5.1M) and ensure all air is vented at the rad, record the head and flow on this CP setting and then just change to PP 5.1 and again record the head and flow. Repeat this process in all the rads individually, both D/stairs & U/stairs and record everything, it might tell you something.
You could then just open all the D/stairs rads only and again record the head/flow on both CP&PP mode and then ditto for the U/stairs (D/stairs off).

Ther's no point in me prattling on I think except to say that I presume the E.vessel pressure gauge is rising/falling with boiler hot/cold, this will check (sort of) that the pipe work between the E.vessel and the system is clear and that you have a fully pressurised system.

Yes, I think that you should shut off the Air separator, can you please post a link?

I'll leave it at that for the moment.

 

[hallra]

Thanks, John, for the reply, it's interesting every time to see what your thoughts are...

I presume to check that the pump is on the flow side of the boiler is by feeling where the heat goes...
Whenever I've checked, the first pipe to give off heat is the one below the pump, which should be correct one as the arrow on pump is pointing upwards and the arrows on the two-way valves are pointing away from the pump...

Getting rid of air is a questionable one as I can't find any air anywhere but always have a suspicion that air is trapped somewhere.
- One interesting thing I have seen time to time with the new gauge below the expansion tank is that, when I let the system cool down I see the pressure drop on the gauge, I then top the system back up, it will rise rapidly, going from say 0.5bar to 1.5bar, then I turn the system on to heat for a bit, stop it, let it cool down and then again I see the pressure drop to 0.5bar, then I top up again... I had to repeat this process numerous times on Thursday (after putting the ABV back and changing the TRV bodies) till eventually it stopped occurring... However, yesterday when playing around, a few times I let the system cool down to then find myself with a pressure drop... which I then filled again... repeating a few time... It got me questioning whether the filling loop which is using 10mm flexible braided hose, is too narrow and perhaps is introducing air into the system... Being that the water entering under 3bar of pressure is separating as it is forced through the 10mm hose... I'm sure I've read that this can happening...


When you say about up/down radiators not heating together, I'm not sure if that is the case or maybe I have described it incorrectly...

Both upstairs and downstairs are heating up, just I would describe it as not in balance... That is that the radiators don't have equal heat on flow/return and some struggle to have heat when the pump is on lower settings...
- I thought that is a typical description of unbalanced radiators... Have I misunderstoood?

FYI, here are some numbers I took yesterday when trying to manually balance with the pump on:
- I think the system had been heating around 10/15 mins, I didn't note it down, I can't remember which pump setting I had it on, possibly CC at 65%, I would need to repeat to be 100%.

Isolating valves either side of PRV... What valves, there aren't any that I see... I also believe that have isolating valves should not be either side to ensure the PRV isn't accidently isolated... Can you point out to me what you are seeing?
- I was considering putting a service valve below the expansion tank to allow correct testing of the air side of expansion vessel.

When I pressure tested the air side of the expansion vessel, I had to drain down the water to isolate it...
- Altecnic (Caleffi) tech support advised:

Pressure settings: 1.6bar air side & 1.4bar system side.

I asked about the fact that the pressure gauge doesn't go up with heat and got told that was correct behaviour...

I asked to make sure gauge & vessel were the right way up.

I also asked about air in the system.

It looks like at some point, the conversation stopped, I probably got distracted and forgot about it... So if need be I can go back to them to ask further questions...


How do I check the MVs are opening fully?

- They are both definitely opening, % wise, no idea how to check...

- However, I noticed yesterday that the MV to upstairs was buzzing, which in my mind is an indication that it is starting to fail. In the past one of the MVs failed, I think it was the upstairs previously as well... I know the downstairs one was plumped in backwards, which I only noticed, had corrected in Oct 2018.
- If you think it is wise, I can always do as I said previously, which is take out one of the MVs, so only have one MV for the whole house.... Guess it would then rule out a number of potential issues... would require a little change to the pipework...


Ooohhh, I like your idea of isolating each radiator one at a time, to bleed them... Tomorrow, I will do this, record the numbers and we can discuss results...

- I do remember watching a youtube video which someone did this... What they also did was keep the fill loop open and controlled via PRV, they then isolated each radiator, opening the lockshield drain off to flush air that was trapped out... I actually bought a PRV to do this very thing. However, I didn't actually implement this as I hadn't all the connections to implement and then again got distracted... So, if needed, can do this later...

Anyway, now I'm waffling on, so thanks for the advice, I'll come back to you tomorrow.

 

[hallra]

This is a report that is produced by the balancing softwere after the balancing process is complete, might be some useful information in this?

 

[John.g]

Thanks, John, for the reply, it's interesting every time to see what your thoughts are...

I presume to check that the pump is on the flow side of the boiler is by feeling where the heat goes...
Whenever I've checked, the first pipe to give off heat is the one below the pump, which should be correct one as the arrow on pump is pointing upwards and the arrows on the two-way valves are pointing away from the pump...

Getting rid of air is a questionable one as I can't find any air anywhere but always have a suspicion that air is trapped somewhere.
- One interesting thing I have seen time to time with the new gauge below the expansion tank is that, when I let the system cool down I see the pressure drop on the gauge, I then top the system back up, it will rise rapidly, going from say 0.5bar to 1.5bar, then I turn the system on to heat for a bit, stop it, let it cool down and then again I see the pressure drop to 0.5bar, then I top up again... I had to repeat this process numerous times on Thursday (after putting the ABV back and changing the TRV bodies) till eventually it stopped occurring... However, yesterday when playing around, a few times I let the system cool down to then find myself with a pressure drop... which I then filled again... repeating a few time... It got me questioning whether the filling loop which is using 10mm flexible braided hose, is too narrow and perhaps is introducing air into the system... Being that the water entering under 3bar of pressure is separating as it is forced through the 10mm hose... I'm sure I've read that this can happening...


When you say about up/down radiators not heating together, I'm not sure if that is the case or maybe I have described it incorrectly...

Both upstairs and downstairs are heating up, just I would describe it as not in balance... That is that the radiators don't have equal heat on flow/return and some struggle to have heat when the pump is on lower settings...
- I thought that is a typical description of unbalanced radiators... Have I misunderstoood?

FYI, here are some numbers I took yesterday when trying to manually balance with the pump on:
- I think the system had been heating around 10/15 mins, I didn't note it down, I can't remember which pump setting I had it on, possibly CC at 65%, I would need to repeat to be 100%.

View attachment 37039

Isolating valves either side of PRV... What valves, there aren't any that I see... I also believe that have isolating valves should not be either side to ensure the PRV isn't accidently isolated... Can you point out to me what you are seeing?
- I was considering putting a service valve below the expansion tank to allow correct testing of the air side of expansion vessel.

When I pressure tested the air side of the expansion vessel, I had to drain down the water to isolate it...
- Altecnic (Caleffi) tech support advised:

Pressure settings: 1.6bar air side & 1.4bar system side.

I asked about the fact that the pressure gauge doesn't go up with heat and got told that was correct behaviour...

I asked to make sure gauge & vessel were the right way up.

I also asked about air in the system.

It looks like at some point, the conversation stopped, I probably got distracted and forgot about it... So if need be I can go back to them to ask further questions...


How do I check the MVs are opening fully?

- They are both definitely opening, % wise, no idea how to check...

- However, I noticed yesterday that the MV to upstairs was buzzing, which in my mind is an indication that it is starting to fail. In the past one of the MVs failed, I think it was the upstairs previously as well... I know the downstairs one was plumped in backwards, which I only noticed, had corrected in Oct 2018.
- If you think it is wise, I can always do as I said previously, which is take out one of the MVs, so only have one MV for the whole house.. Guess it would then rule out a number of potential issues... would require a little change to the pipework...


Ooohhh, I like your idea of isolating each radiator one at a time, to bleed them... Tomorrow, I will do this, record the numbers and we can discuss results...

- I do remember watching a youtube video which someone did this... What they also did was keep the fill loop open and controlled via PRV, they then isolated each radiator, opening the lockshield drain off to flush air that was trapped out... I actually bought a PRV to do this very thing. However, I didn't actually implement this as I hadn't all the connections to implement and then again got distracted... So, if needed, can do this later...

Anyway, now I'm waffling on, so thanks for the advice, I'll come back to you tomorrow.

Expansion Vessel: You say 1.6 bar air side and 1.4 bar water side, the (cold) filling pressure should never be lower than the pre pressure, ideally it should be 0.3 to 0.5 bar higher to give you a little water reserve of 1 to 2 litres which means very infrequent top ups, your pre pressure of 1.6 bar is a little high to do this but I would advise filling to 1.75/1.80 bar when system is cold but no higher as the boiler safety valve lifts at 3.0 bar.
Obviously you have to top up frequently if your are venting rads etc but once finished then if you still have to top up frequently will be indicative of a leak somewhere so when you have the system back to normal keep a eye on this, I would not recommend the fitting of a PRV, sometimes called a auto fill valve as this masks any leakage problems when left open, this is what I was referring to as I thought that you had one fitted to your fill line.
PRV refers to both a Pressure Relief Valve (safety valve) or a Pressure Reducing Valve.
I will attach a little calculation to show the effect of pre and fill pressures on the boiler final pressure.

Re balancing: I would start with all the L.shield valves fully open and then take the DeltaTs on all of them and only throttle in the ones that have the lowest DeltaTs and do it with the pump on PP5.1 setting, maybe that's how you are doing it anyhow, as I said previously once they are all reasonably balanced then you can reduce the pump head as required to give you a greater DeltaT if required. The main thing to avoid is having ALL the L.shield valves throttled as this can cause noisy operation.

You don't really have to do all those individual tests that I suggested above but it would certainly be interesting.

Just thinking again about any other restrictions in your system, I know that you can't test it but is there any possibility that the boiler heat exchanger is partially blocked? the E.vessel is piped in before this, it will affect pump operation if the exchanger is partially blocked, I don't have any experience of sealed heating systems but I might have thought that the E.vessel piping would have connected in just before the pump suction, but again no problem where it is if the exchanger is clean.

Any link to your Air Separator?.

 

[John.g]

This is a report that is produced by the balancing softwere after the balancing process is complete, might be some useful information in this?

Very interesting , I must read it properly later on, is that done with just any one rad on at the time?.

I also read that your boiler has a stainless heat exchanger so that's probably why they claim no bypass required.

 

[hallra]

Expansion Vessel: You say 1.6 bar air side and 1.4 bar water side, the (cold) filling pressure should never be lower than the pre pressure, ideally it should be 0.3 to 0.5 bar higher to give you a little water reserve of 1 to 2 litres which means very infrequent top ups, your pre pressure of 1.6 bar is a little high to do this but I would advise filling to 1.75/1.80 bar when system is cold but no higher as the boiler safety valve lifts at 3.0 bar.
Obviously you have to top up frequently if your are venting rads etc but once finished then if you still have to top up frequently will be indicative of a leak somewhere so when you have the system back to normal keep a eye on this, I would not recommend the fitting of a PRV, sometimes called a auto fill valve as this masks any leakage problems when left open, this is what I was referring to as I thought that you had one fitted to your fill line.
PRV refers to both a Pressure Relief Valve (safety valve) or a Pressure Reducing Valve.
I will attach a little calculation to show the effect of pre and fill pressures on the boiler final pressure.

Re balancing: I would start with all the L.shield valves fully open and then take the DeltaTs on all of them and only throttle in the ones that have the lowest DeltaTs and do it with the pump on PP5.1 setting, maybe that's how you are doing it anyhow, as I said previously once they are all reasonably balanced then you can reduce the pump head as required to give you a greater DeltaT if required. The main thing to avoid is having ALL the L.shield valves throttled as this can cause noisy operation.

You don't really have to do all those individual tests that I suggested above but it would certainly be interesting.

Just thinking again about any other restrictions in your system, I know that you can't test it but is there any possibility that the boiler heat exchanger is partially blocked? the E.vessel is piped in before this, it will affect pump operation if the exchanger is partially blocked, I don't have any experience of sealed heating systems but I might have thought that the E.vessel piping would have connected in just before the pump suction, but again no problem where it is if the exchanger is clean.

Any link to your Air Separator?.

Hi John,

What do you mean by pre-pressure?

From what I understand, are you saying the complete opposite to what Altecnic support line has advised me?

I.E The water side should be 0.3 - 0.5 than the air side?

Why on earth would they tell me the complete opposite?
- Someone on here prior to that, told me to drop the pressure to 1bar on both sides, when that caused problems, I spoke to Altecnic.
- FYI, I have an 18ltr Reflex expansion vessel fitted.
- I understand about the safety valve set at 3bar.
- I also know/understand not to have the Pressure Reducing valve permanently connected, it was for the purposes of driving trapped air out.


- Do you have that calculation to show the effect of pre and fill pressures on boiler final pressure?


Thanks for the advice on the throttling, i'll probably test/record everything, it's useful info.

I would say a good chance that the boiler exchange is partially blocked, as when I flushed all the Rads, it appeared to me that the system never had inhibitor in it.

The boiler was probably never flushed, it took 2 years for the builder (Persimmons) to send someone in to commision the biler and fill in the paperwork... what with that and black water and small metal fillings that came out when I flushed the rads...


Air Separator
-------------

Spirotech Spirovent RV2 Air Separator (Brass) - -: SpiroVent Air Separator 22mm

Spirotech | maximising performance

 

[hallra]

Very interesting , I must read it properly later on, is that done with just any one rad on at the time?.

I also read that your boiler has a stainless heat exchanger so that's probably why they claim no bypass required.

The 'Go Balance' is done with all Rads and H/W off, to take a zero flow reading, then turning one on at a time to do readings and then one where you do reading across two open rads (I think it chooses the two with the highest flow, forget the name they call it)

Once all rad readings, rad specs and room specs are taken, you return to each rad, turning on one at a time, to do the actual balancing.

 

[hallra]

Whilst I remember, a plumber who worked for Persimmons did mention at one point early on that their was something fundamentally wrong with the microbore pipework in the walls. However he would never say what it was as he would be fired.

Never did get to the bottom of it, whether it was really bad or something he just didn’t agree with...

That’s the problem, you cannot really trust anyone or any company.

I now know this plumber quite well and he know longer works for Persimmons, I will try to find out what he was referring to.

 

[John.g]

Hi John,

What do you mean by pre-pressure?

From what I understand, are you saying the complete opposite to what Altecnic support line has advised me?

I.E The water side should be 0.3 - 0.5 than the air side?

Why on earth would they tell me the complete opposite?
- Someone on here prior to that, told me to drop the pressure to 1bar on both sides, when that caused problems, I spoke to Altecnic.
- FYI, I have an 18ltr Reflex expansion vessel fitted.
- I understand about the safety valve set at 3bar.
- I also know/understand not to have the Pressure Reducing valve permanently connected, it was for the purposes of driving trapped air out.


- Do you have that calculation to show the effect of pre and fill pressures on boiler final pressure?


Thanks for the advice on the throttling, i'll probably test/record everything, it's useful info.

I would say a good chance that the boiler exchange is partially blocked, as when I flushed all the Rads, it appeared to me that the system never had inhibitor in it.

The boiler was probably never flushed, it took 2 years for the builder (Persimmons) to send someone in to commision the biler and fill in the paperwork... what with that and black water and small metal fillings that came out when I flushed the rads...


Air Separator
-------------

Spirotech Spirovent RV2 Air Separator (Brass) - -: SpiroVent Air Separator 22mm

Spirotech | maximising performance

View attachment 37045

The pre pressure is the air pressure in the E.vessel with no pressure on the water side, or with the E.vessel unconnected. The filling pressure is then the pressure after admitting water to it with boiler and system contents cold.
I have posted the spreadsheet above, "Expansion vessel calculation extract", you can put your own figures into it and see what the final pressure will be, for example with a 18 ltr E.vessel and a pre pressure of even 1.6bar and a fill pressure of 2bar and based on a expansion vol of 2.5 litres then the final pressure would be 2.6 bar.
I would suggest, when you get a chance, to drop the pre pressure to 1 bar and and set the fill pressure to 1.5 bar and you will have a nice little water reserve and a very low final pressure.

Maybe the guys at Altecnic who gave you that great advice were from Cork??.

With a 18 litre E,vessel, a 1.0 bar pre pressure and a 1.5 bar filling pressure will give you a water reserve of a very nice 3.6 litres and a final pressure of only 2.03 bar.
That is is one very big advantage of a external E.vessel as you cannot oversize it but the integrated ones in the boilers are only 8 litres or so.

What problems did dropping the pre and filling pressure to 1.0 bar cause?? was it pump noise?, if so then maybe leave the pre pressure at 1.6 bar and the fill pressure at 2.0 bar, but just observe what the final pressure is when everything is nice and hot.

 

[hallra]

Thanks, looks like I’ve got my hands full tomorrow...

If I’m going to do the expansion vessel pre-Pressure, I might as well add a service valve:

https://www.NoLinkingToThis/p/tesla...T5Z70ngv-_vkydQXFlhoCc34QAvD_BwE&gclsrc=aw.ds

And whilst I’m doing that, seeing I would drain down the system, what do you think about moving the expansion vessel to the pipework before the pump?
- just in case a partial heat exchange blockage?
- I’ve checked the boiler install instructions put the expansion vessel before the pump and with the pipe layout wouldn’t be to much to move it over...

 

[John.g]

Thanks, looks like I’ve got my hands full tomorrow...

If I’m going to do the expansion vessel pre-Pressure, I might as well add a service valve:

https://www.NoLinkingToThis/p/tesla...T5Z70ngv-_vkydQXFlhoCc34QAvD_BwE&gclsrc=aw.ds

And whilst I’m doing that, seeing I would drain down the system, what do you think about moving the expansion vessel to the pipework before the pump?
- just in case a partial heat exchange blockage?
- I’ve checked the boiler install instructions put the expansion vessel before the pump and with the pipe layout wouldn’t be to much to move it over...

I think some plumber here at home told me that he was informed that it is'nt legal here at any rate to fit a isolating valve, I presume because it can be left shut but if it is illegal it seems a bit daft as dozens of E.vessels fail due to a ruptured bladder, the auto fill valve or the house holder re pressurizes to 1 bar and as soon as the water heats up it lifts the boiler safety valve as there is now no expansion volume in the "broken" E.vessel.

Re relocating the E.vessel piping, on reflection that might not be a great idea because if there is a exchanger partial blockage then it just might cause a very low water pressure in the exchanger which could lead to other problems.