Recent house purchase - CH/HW Major issues.

[John.g]

Uncannily like this, with a UPS2 pump.

Air Problem in Open Vented System after Boiler Change - UK Plumbers Forums

Hi All, First post here, so please be kind! I am currently having a lot of trouble with air and related noise in my open vented heating system. Long story, with lots of things tried already, so please bear with me… Firstly, a photo of the heart of the system in the garage as it is today (lots...

www.plumbersforums.net

 

[Dale_R]

Uncannily like this, with a UPS2 pump.

Air Problem in Open Vented System after Boiler Change - UK Plumbers Forums

Hi All, First post here, so please be kind! I am currently having a lot of trouble with air and related noise in my open vented heating system. Long story, with lots of things tried already, so please bear with me… Firstly, a photo of the heart of the system in the garage as it is today (lots...

www.plumbersforums.net

Thank you for finding that thread, I've been searching for it on here since you mentioned someone had a similar issue.
What a shame they didn't come back on here and let everyone know what the problem was.

 

[Dale_R]

I've made a video to show the noise from the system, it's throughout the whole house, every radiator, all pipework and at the boiler.
This only happens when the system gets up to temperature. From a cold start it is silent up until the water gets hot, then if I turn the boiler off as the system cools down it goes silent again.

I'm not really getting any air in the radiators and I've been checking the F&E tank, I'm getting no pump over at any pump speed and no change of level in the F&E tank.

Also I returned the Wilo pump and fitted a Grundfos UPS3 today. It is MUCH quieter.

I'm currently trying to find the best speed to run it at, I've had it on PP1 but the livingroom 2 metre wide double radiator doesn't get hot and the same with the tall vertical radiator in the kitchen. I'll try it on PP2 for a bit.

Video:

 

[ShaunCorbs]

That’s air in the pipework moving

 

[Dale_R]

That’s air in the pipework moving

I can't seem to shift it.
It only happens when it gets hot.

 

[John.g]

I've made a video to show the noise from the system, it's throughout the whole house, every radiator, all pipework and at the boiler.
This only happens when the system gets up to temperature. From a cold start it is silent up until the water gets hot, then if I turn the boiler off as the system cools down it goes silent again.

I'm not really getting any air in the radiators and I've been checking the F&E tank, I'm getting no pump over at any pump speed and no change of level in the F&E tank.

Also I returned the Wilo pump and fitted a Grundfos UPS3 today. It is MUCH quieter.

I'm currently trying to find the best speed to run it at, I've had it on PP1 but the livingroom 2 metre wide double radiator doesn't get hot and the same with the tall vertical radiator in the kitchen. I'll try it on PP2 for a bit.

Video:

The UPS3 on PP1 is bound to be quit as it will pump almost nothing on that setting, PP2 should/might be sufficient and CP1 at a constant 3.0M certainly will.

 

[Dale_R]

The UPS3 on PP1 is bound to be quit as it will pump almost nothing on that setting, PP2 should/might be sufficient and CP1 at a constant 3.0M certainly will.

PP2 seems to be heating up all the radiators and is still very quiet.

 

[John.g]

But, Is system still very noisy once the temperature is increased??. I still am not confinced that you are not pulling air into the system as your vent/cold feed is not conventional, the traditional H (VCP) system is like one below and a combined cold feed & vent IMO should be combined up at the F&E tank with the cold feed the same diameter as the vent, would be tempted to do as Shaun suggests and seal it but again no cast iron guarantee that that will cure the problem, I would certainly seal it in preference to messing around now with any other methods.

 

[Dale_R]

But, Is system still very noisy once the temperature is increased??. I still am not confinced that you are not pulling air into the system as your vent/cold feed is not conventional, the traditional H (VCP) system is like one below and a combined cold feed & vent IMO should be combined up at the F&E tank with the cold feed the same diameter as the vent, would be tempted to do as Shaun suggests and seal it but again no cast iron guarantee that that will cure the problem, I would certainly seal it in preference to messing around now with any other methods.

Yes it's still very noisy when the temperature increases.

I thought this was conventional, it took me a while to work out the difference with that picture and what I can see is the tees are in different places, I've drawn a quick picture which I will post below to see if I've got this right.

I have had the vent pipe in a jug full of water for a couple of days, I assumed it couldn't be a vent issue as there would be no way to suck air in with the vent pipe submerged? Also this issue has only been present since I cleaned all the magnetite out and got the radiators going, surely it must have all worked at some point and the part that it's only happening when it gets hot is what I cant get my head around. I could run it forever with the boiler switched off or at a low temp at any pump speed and its fine.

It will be the last resort if I have to seal the system, I don't know if I trust the microbore manifolds under any additional pressure as they are hidden in the building and I have no way to inspect them if anything goes wrong.

 

[ShaunCorbs]

Seal it at 0.5 bar the pump is pushing that much on the system already

 

[Dale_R]

Seal it at 0.5 bar the pump is pushing that much on the system already

I could go down that path, but it surely as I have a jug on the vent pipe with water in it there is no way air can be sucked in through there?

Im concerned there is something wrong in the CH circuit or the boiler, either something creating oxygen, hydrogen or the heat exchanger is faulty as it only happens at a certain temp.

 

[ShaunCorbs]

You could try caping the vent temporarily while you watch the system and then once finished the test you remove the cap leave the feed open

 

[Dale_R]

You could try caping the vent temporarily while you watch the system and then once finished the test you remove the cap leave the feed open

Yeah, that might be worth trying.

 

[John.g]

I could go down that path, but it surely as I have a jug on the vent pipe with water in it there is no way air can be sucked in through there?

Im concerned there is something wrong in the CH circuit or the boiler, either something creating oxygen, hydrogen or the heat exchanger is faulty as it only happens at a certain temp.

Does the boiler do a pump overrun when cylinder or room stats satisfied/, if so you might note if noise still persists for the pump overrun period, select CH only, turn roomstat up, ensure boiler flow temp set to 70C, wait for a few minutes once the noise commences and turn down the roomstat to shut down the burner/boiler.

Other suggestion is to drain the whole system down again and refill with no inhibitor and see what happens.

 

[Dale_R]

Does the boiler do a pump overrun when cylinder or room stats satisfied/, if so you might note if noise still persists for the pump overrun period, select CH only, turn roomstat up, ensure boiler flow temp set to 70C, wait for a few minutes once the noise commences and turn down the roomstat to shut down the burner/boiler.

Other suggestion is to drain the whole system down again and refill with no inhibitor and see what happens.

Hi John.g

This boiler does not have a pump over-run, the pump is controlled by the microswitch in the Mid position valve.

I have done similar to that test by running the system from cold, letting the boiler get up to temp, waiting for the noise than switching only the boiler off which leaves the pump running. It will get quieter as the water cools down and then reaches a point where it is silent.

I'm planning on dropping the system again today, I noticed a gate valve weeping from the stem on the CH feed, I nipped up the packing nut but the behaviour of the valve is quite strange when I turn it, if I turn it anti-clockwise there it will do a full turn, meet resistance, then do the remainder of turns while the stem pops back in! I don't want to run the risk of the internals falling in to the heating system so going to replace that.

Also I think I will add a lever ball or gate vale to HW flow while it's drained down, as that will enable me to be able to replace the Mid position valve or the automatic bottle vent without draining the system down, which will be quite useful for maintenance.

I was pondering something, the first time I ever drained the system down I did not tie up the float valve as I was just desperate to change the mod position valve and I foolishly thought it would be clean in there as the house is only 20 years old and the F&E tank has a cover, so that would have allowed the F&E tank to completely drain in to the system with that rusty/orange water/mud.

And the last time I drained it down I was bailing out the tank and wiping the mud out but I accidentally knocked the float valve which allowed the tank to start filling up again and this stirred up water started going down the cold feed. I did however leave the header tank feed running for quite a bit to hopefully flush that out of the system.

I took some water out of a rad and it does have an orange/brown tinge to it, I think it would be a good idea to give it a good clean again.

Would X400 do the trick and leave it in for a few weeks, or is there something else I should be using for orange/brown water?

 

[John.g]

I would be inclined to just give the system a good flush through then after manually latching the diverter valve in mid position refill it very very slowly by tying up the ball cock to let the water trickle down through the F&E tank and down through the cold feed, this should/may allow air to vent up through the vent and still allow water down the same vent pipe, thats how I refill mine but I have a service 1/2 ins isolating valve on the cold feed to the F&E tank, I have no AAVs anywhere in the system and can run the circ pump at any speed I like with never a sign of air. Maybe also blank off the vent as suggested even if only temporarily.
Your system sounds as if still full of air but you are getting no proof of this when venting/bleeding the rads, weird.

 

[ShaunCorbs]

Stick x800 in for a day and run it hot then go round and drain it out

 

[Dale_R]

While I'm in there I would like to fit a magnetic filter.
However I do not have access to the boiler return feed as that is under the floor.

Magnaclean state it cannot go on to the flow, I'm assuming this is due to having isolation valves which someone could accidentally close stopping the boiler venting? Are there any of these units that can be fitted to the flow, such as the Fernox Omega?

 

[John.g]

Just going on a different tack, (pump cavitation), what is the distance (approx) from the water level in the F&E tank to the pump?.

 

[Dale_R]

Hi All,

I'm not being one of those that solves an issue and doesn't return with an update so posting a quick update.

I put some X400 in a couple of weeks ago, I left it in there and the system is definitely getting quieter, I'd say its 85% better!
I will leave it a bit longer till it's been in there 4 weeks, then drain it down and fill it with X100.

However we are having a few people out to quote for a new boiler, as this seems to be playing up and having a few failed start ups/cycling happening.

 

[Timmy D]

Just want to say that I’ve just seen this post and read through it.

It was a good read, you gave great details and a concise breakdown.

If you ever need a job, I’d hire you 🙂

 

[Dale_R]

Just want to say that I’ve just seen this post and read through it.

It was a good read, you gave great details and a concise breakdown.

If you ever need a job, I’d hire you 🙂

Thanks for your reply it made me smile 🙂

I'm an electronics/industrial control/electrical engineer and I'm in the process of looking at a change of career as it goes! I've been looking at courses for Gas Safe/Boiler repair and domestic electrical.

The industry I've worked in has gradually disappeared and nothing is repaired any more, it was thriving in this area with lots of electronic work but all the major manufacturers closed all the factories.

Now I'm self employed and it's getting more difficult each day. So time to start again and go down another path.

My parent inlaws had an issue with their Worcester 25Si and could not get an engineer out for days, they are elderly and were going to be without heating/hw.

The first engineer misdiagnosed it and I explained what I thought the issue was, the second engineer turned up with the wrong parts as I expected. I spoke to him and said the wireless thermostat receiver is faulty and the hw issue is down to the heat exchanger plate. He actually listened, ordered those parts and it's all working. Both of them said there is a lack of engineers around here and that got me thinking, I might look in to doing some courses and getting qualified if there is work out there and someone would take me on.

Im thinking as I have an electronic, electrical and mechanical background that could help.

 

[Timmy D]

Thanks for your reply it made me smile 🙂

I'm an electronics/industrial control/electrical engineer and I'm in the process of looking at a change of career as it goes! I've been looking at courses for Gas Safe/Boiler repair and domestic electrical.

The industry I've worked in has gradually disappeared and nothing is repaired any more, it was thriving in this area with lots of electronic work but all the major manufacturers closed all the factories.

Now I'm self employed and it's getting more difficult each day. So time to start again and go down another path.

My parent inlaws had an issue with their Worcester 25Si and could not get an engineer out for days, they are elderly and were going to be without heating/hw.

The first engineer misdiagnosed it and I explained what I thought the issue was, the second engineer turned up with the wrong parts as I expected. I spoke to him and said the wireless thermostat receiver is faulty and the hw issue is down to the heat exchanger plate. He actually listened, ordered those parts and it's all working. Both of them said there is a lack of engineers around here and that got me thinking, I might look in to doing some courses and getting qualified if there is work out there and someone would take me on.

Im thinking as I have an electronic, electrical and mechanical background that could help.

From this post, I think you’ve got a good chance to make it, if you put the effort in and are prepared to drop wages while you’re learning.

I’ve got a friend who owns a smallish plumbing company who lives out in Pembrokeshire (saw your profile said South Wales). If you fancy having a chat with him and maybe going out with him/one of of his guys for a trial day or two (to see if you do fancy it), I can ask if he’s willing/got space for an apprentice?