Which is the more powerful pump?

[rcpilot]

Hi all just picking your brains 2 pumps with flow rates of 3.8 and 5.7 which is the more powerful, also can you fit a commercial pump into a domestic system?

 

[rcpilot]

Yes, a prime suspect, its quite possibly closed now so if the threads arn,t stripped you should get 3 to 5 full turns anticlockwise from it , there's always a 1/2 to 3/4 of free play before they start to open or close.


Only as a very last resort IMO, get the pump working and we can see then if required.

If you do get it opened then leave it as Don,t require any more closed valve readings

Ok John I will strip the Alpha3 out check the gate valve, if it is ok I will put the Alpha 2 back in to see if that makes any difference, will get back to you when it's done could be a few days, one thing I forgot to tell you is I suffer from a back problem, when I was working as a service engineer for a firm that serviced and repaired lifts,hoists cranes etc I fell off an overhead crane over in Carlisle many years ago and I back pain when i do too much

 

[John.g]

Did you manage to open it, remove handwheel and use a adjustable spanner as a lever.

Maybe just renew the gate valve and take from there, you can always check pumps later as you can isolate them?

 

[rcpilot]

Did you manage to open it, remove handwheel and use a adjustable spanner as a lever.

Maybe just renew the gate valve and take from there, you can always check pumps later as you can isolate them?

Hi john well striped the Alpha 3 out and guess what, both valves were barely open so that was the restriction to flow, I renewed some of the pipe work to one of the radiators because it had a service valve on it and it was leaking and I am now cleaning up after the work, if everything is hunky dory with the system what is the best setting for the Alpha 3 and I might try to balance it with the go balance app.
Ken

 

[John.g]

That's good news Ken, I would set it to CC3 to start with, if you have to close all the rad valves individually (no u/staors/d/stairs zoning), then just run it as is, ie, if d/stairs only opened up now just start the pump and post the numbers, you can then open up the u/stairs and run both systems together on CC3 and have a look at those numbers.
Don't know what the total rad(s) output is but assuming 20kw max then the flowrate required will be 20LPM (1.2M3/hr) at a rad dT of 14/15C/kw which would result in a pump head of 4.7M in CC3 mode, see what you come up with anyway and you can decide on balancing, if any, is required later.

My system, 12 rads, 20kw, no balancing, works fine at a 3.5M head.

 

[rcpilot]

That's good news Ken, I would set it to CC3 to start with, if you have to close all the rad valves individually (no u/staors/d/stairs zoning), then just run it as is, ie, if d/stairs only opened up now just start the pump and post the numbers, you can then open up the u/stairs and run both systems together on CC3 and have a look at those numbers.
Don't know what the total rad(s) output is but assuming 20kw max then the flowrate required will be 20LPM (1.2M3/hr) at a rad dT of 14/15C/kw which would result in a pump head of 4.7M in CC3 mode, see what you come up with anyway and you can decide on balancing, if any, is required later.

My system, 12 rads, 20kw, no balancing, works fine at a 3.5M head.

I have bled all the rads but left the kitchen one out of it for the time being, the bathroom towel rails are getting mad hot and the sitting room is starting to heat up, nothing yet in the bedrooms but I suppose balancing will bring them up

 

[John.g]

With CC3?
What pump values are you getting?

 

[John.g]

You said in post #1 that the upstairs rads were heating but not downstairs?,
If you have a Y system with a mid position valve then just carry out the basic check that the pump arrow is pointing towards it, also ensure that system is pressurized to 1.3/1.5 bar.
Can you also take pump values with DHW heating only on, then with (eventually) DHW+d/Stairs+U/stairs.

 

[rcpilot]

You said in post #1 that the upstairs rads were heating but not downstairs?,
If you have a Y system with a mid position valve then just carry out the basic check that the pump arrow is pointing towards it, also ensure that system is pressurized to 1.3/1.5 bar.
Can you also take pump values with DHW heating only on, then with (eventually) DHW+d/Stairs+U/stairs.

Hi John, this flaming thing has got me demented, when I put everything back together, filled the system, bled the radiators, then started it up it was showing 24 watts on the pump and I think 0.6m3/h and the towel rads were getting mad hot the big rad downstairs was getting hot, both bedrooms were cold obviously because the lockshields were closed, the entrance rad was still cold, so I turned it off. Today I turned it back on and got the same results, so I started to manually balance the towel rails got them somewhere near the 12 deg difference checked the pump and the wattage had gone down to 15 and the m3/h was showing 0.0, hair now all over the floor.

 

[rcpilot]

Hi John, this flaming thing has got me demented, when I put everything back together, filled the system, bled the radiators, then started it up it was showing 24 watts on the pump and I think 0.6m3/h and the towel rads were getting mad hot the big rad downstairs was getting hot, both bedrooms were cold obviously because the lockshields were closed, the entrance rad was still cold, so I turned it off. Today I turned it back on and got the same results, so I started to manually balance the towel rails got them somewhere near the 12 deg difference checked the pump and the wattage had gone down to 15 and the m3/h was showing 0.0, hair now all over the floor.

Hi John decided to check the pump with the "go remote app" that pump has got a mind of it's own it reset itself from CC to CP so I reset it to CC and operating @ max it went back to showing 24 watts but the flow rate remained @ 0.0m3/h

 

[John.g]

Balancing should be the last thing to do IMO.
Can you just run on DHW and check values as this is practically a short circuit through the cylinder coil where most of the short? run will/should be in 22mm, if there is a balancing gate valve on the coil return, just open it fully.
I would expect to see ~ 34W on CC3.

 

[rcpilot]

Balancing should be the last thing to do IMO.
Can you just run on DHW and check values as this is practically a short circuit through the cylinder coil where most of the short? run will/should be in 22mm, if there is a balancing gate valve on the coil return, just open it fully.
I would expect to see ~ 34W on CC3.

I will call for hot water as the( data term) will allow me to press for one shot hot water the "Y" plan valve should close the heating down and open the hot water circuit up, if that does not work are the Alpha 3 and the Alpha 2 exactly the same apart from the control panel if so Instead of going down the road of taking the Alpha 3 out I could just change the heads and see what that does

 

[rcpilot]

Balancing should be the last thing to do IMO.
Can you just run on DHW and check values as this is practically a short circuit through the cylinder coil where most of the short? run will/should be in 22mm, if there is a balancing gate valve on the coil return, just open it fully.
I would expect to see ~ 34W on CC3.

Hi John I called for hot water and it immediately went up to 34 watts and the flow rate went up to 0.6m3/h

 

[rcpilot]

Hi John I called for hot water and it immediately went up to 34 watts and the flow rate went up to 0.6m3/h

So when the hot water reached it's temperature the "Y" plan valve closed the hot water circuit and opened the rad circuit the wattage went back to 15 flowrate 0.0m3/h, so I opened the lockshield valves on the towel rails and the wattage went back up to 34watts and the flow rate up to 0.6m3/h what would take that to mean?

 

[John.g]

Hi John I called for hot water and it immediately went up to 34 watts and the flow rate went up to 0.6m3/h

That points to something else rather than a pump problem, once the pump reaches max power then it will only display 0.6M3/hr, but it could be pumping 1M3/hr @ 5M or 1.5M3/hr @ 4M and so on depending on pipe/coil friction losses.

 

[John.g]

So when the hot water reached it's temperature the "Y" plan valve closed the hot water circuit and opened the rad circuit the wattage went back to 15 flowrate 0.0m3/h, so I opened the lockshield valves on the towel rails and the wattage went back up to 34watts and the flow rate up to 0.6m3/h what would take that to mean?

It would mean that there is no real restrictions in the upstairs pipe work.
Can you ensure all d/stair rad valves including lockshields are fully open, then shut all upstairs (one valve on each rad will do) then take pump values on d/stairs only.

 

[rcpilot]

It would mean that there is no real restrictions in the upstairs pipe work.
Can you ensure all d/stair rad valves including lockshields are fully open, then shut all upstairs (one valve on each rad will do) then take pump values on d/stairs only.

ok will do

 

[rcpilot]

ok will do

Right opened all the rads downstairs no change, still 34 watts, closed off both bedrooms again no change still 34watts, but as soon as I touched the towel rails the wattage went down to 16 flowrate 0.0m3/h, any suggestions?

 

[rcpilot]

Right opened all the rads downstairs no change, still 34 watts, closed off both bedrooms again no change still 34watts, but as soon as I touched the towel rails the wattage went down to 16 flowrate 0.0m3/h, any suggestions?

the wattage is back up to 22 watts but the flow rate remains at 0.0m3/h

 

[rcpilot]

the wattage is back up to 22 watts but the flow rate remains at 0.0m3/h

Hi john just been looking at the dates I bought the towel rails and the Alpha 3:- bought the rails on the 23/6/2021, I can remember I had problems when I plumbed them in so finished the job (after set backs of one sort or another) 2 months later, bought the Alpha 3 on the 27/4/2022 but that was after we had been away on holiday, so between finishing the rail installs and noticing that the heating was'nt working as well was about 4 months, everything seems to stem from when I put in the towel rails, just wondered if I have done something wrong will have to check to find out but we are going away again in our caravan so probably won't do that until we come back, what do you think? open to suggestions, or a slap on the wrists!

 

[John.g]

Right opened all the rads downstairs no change, still 34 watts, closed off both bedrooms again no change still 34watts, but as soon as I touched the towel rails the wattage went down to 16 flowrate 0.0m3/h, any suggestions?

So, how many rads open d/stairs when all u/stairs rads + towel rads shut off when flow fell to zero??.
If you reopen just one towel rad does the flow increase?
Normally, even if only one rad open fully would expect a flowrate of - 0.3 m3/hrs and a pump power of - 25/26W on CC3.