Loads of air in central heating.

[Chris12345678]

Undertandable but you can improve heat up time for slow rads by ‘balancing’ them. Has reducing the pump speed affected water liss from the system?

There is a 15mm leg that runs down from upstairs, there are three reasonable size radiators on this. These are slow to warm up (lounge / dining room), I was trying to improve these.

The other radiators have the valve (not the TRV) adjusted to different positions to control how they warm up

 

[Harvest Fields]

There is a 15mm leg that runs down from upstairs, there are three reasonable size radiators on this. These are slow to warm up (lounge / dining room), I was trying to improve these.

The other radiators have the valve (not the TRV) adjusted to different positions to control how they warm up

Theres the issue for them rads not heating. 3 rads on one leg??

 

[Chris12345678]

I've not had a chance to test it with the pump on 1 yet!

 

[Mdljk]

Hot water likes to go up. So upstairs rads often heat up easier than downstairs. For that reason you can balance all the upstairs ones by closing the lockshield entitely and then opening say 1/3 of a turn only. That shoukd not adversly affect the upstairs rads but the downstairs rads will now have more heat diverted to them.

 

[Chris12345678]

Hot water likes to go up. So upstairs rads often heat up easier than downstairs. For that reason you can balance all the upstairs ones by closing the lockshield entitely and then opening say 1/3 of a turn only. That shoukd not adversly affect the upstairs rads but the downstairs rads will now have more heat diverted to them.

I didn't know about upstairs heating up quicker, thanks!

 

[Mdljk]

A common misconception is that rads dont need balancing as TRVs take care of that. They dont but modern systems can get away with it. Yours is an old type system and boiker and system will benefit from balancing

 

[Harvest Fields]

A common misconception is that rads dont need balancing as TRVs take care of that. They dont but modern systems can get away with it. Yours is an old type system and boiker and system will benefit from balancing

Who says this?

 

[Mdljk]

Which part Harvestfields?

 

[Harvest Fields]

The first sentence mate. I was always told that all systems should be balanced.

 

[Mdljk]

Me too. But there is a tendency to believe that because TRVs close rads down individually that balancing isnt as important as you and I both know that it actually is - hence my use of “misconception”

 

[Chris12345678]

Ok, thanks. Ones I want to warm up slower are turned right down. I understand about the TRV's not making a difference to warm up speed.


Looking at the radiators, it's only 3 at the front of the house (on a 22mm leg to the first radiator) that are buried in concrete. One of these has never got hot just warm.
It would be fairly easy to put valves on this leg to prove if it is leaking into the ground.

In other news, new electric heaters are working well, but noisy!

 

[Mdljk]

Re-reading your posts about ‘a’ 22 mm pipe and then a rad on ‘a’ 22mm leg. Are you on a ‘One Pipe’ system? Does each rad have a separate flow pipe and a separate return pipe or are both the flow and return coming from the same ‘One’ pipe. As you say the downstairs rads pipes are in concrete you may have to look at the upstairs rads to decide. One pipe systems have their issues. A partial block in the same ‘one’ pipe going both into and out of the boiler will affect circulation easily leading to over pumping especially if pump set to highest speed.

 

[Chris12345678]

Hi, by 'leg' I mean a flow and return. Definitely everything that isn't under concrete is like this. The first radiator from the under concrete pipes is T'd off from a flow and return, I imagine the other two on this leg are the same but can't be definite.

If something is blocked and it is overpumping then where would the water be going?

Thanks for your help

 

[Riley]

Have you turned the pump down as advised

 

[Chris12345678]

Yes but I’ve not had it on since as the kids are in bed and the f&e tank filling and the air noise wakes them.

Forgot to say, someone is coming with a thermal imaging camera tomorrow.

 

[Mdljk]

Hi, by 'leg' I mean a flow and return. Definitely everything that isn't under concrete is like this. The first radiator from the under concrete pipes is T'd off from a flow and return, I imagine the other two on this leg are the same but can't be definite.

If something is blocked and it is overpumping then where would the water be going?

Thanks for your help

Agree. The 4-5 min refill of water being lost each day must be going somewhere and since it is not going up the vent pipe that indicates a leak in the underfloor pipework. Hopefully the thermal imaging camera will locate it. Good luck.

 

[John.g]

Yes but I’ve not had it on since as the kids are in bed and the f&e tank filling and the air noise wakes them.

Forgot to say, someone is coming with a thermal imaging camera tomorrow.

A bit late in the day but have you checked if the F&E tank ball cock is still making up with boiler shut down, system cold and ALL the air vented from the rads, if it isn't then you haven't got a system leak .
Another long shot but costs nothing to check out, the F&E tank is mounted in the loft above the cold water supply tank?, if the cylinder coil is holed/split then the F&E tank would continue to make up but the water would be constantly overflowing from the cold water supply tank even with no usage.

 

[Chris12345678]

Thanks for all the advice.

You know when you get a thread like this and the thread starter suddenly disappears because they are too embarrassed to admit what the problem was........

 

[Mdljk]

Thanks for all the advice.

You know when you get a thread like this and the thread starter suddenly disappears because they are too embarrassed to admit what the problem was....

Come on, tell us.

 

[John.g]

Thanks for all the advice.

You know when you get a thread like this and the thread starter suddenly disappears because they are too embarrassed to admit what the problem was....

No one should feel embarrassed for asking advice on any problem, its a bit like apologizing for asking a stupid question, well as we all know or should know, there is no such thing as a stupid question but there can be plenty of stupid answers.

 

[Harvest Fields]

No one should feel embarrassed for asking advice on any problem, its a bit like apologizing for asking a stupid question, well as we all know or should know, there is no such thing as a stupid question but there can be plenty of stupid answers.

Yep. I have lots of them.

 

[Chris12345678]

So I bought two of these and some automatic bleed valves for each radiator so it should be fixed by tomorrow morning:

https://www.NoLinkingToThis/p/flomasta-0647-central-heating-leak-sealer-500ml/6774r

 

[Chris12345678]

I'm joking.

I thought I'd check the where all the boiler pipes come up from the boiler into a crawlspace. I noticed that a motorised valve was open that shouldn't have been, it should have been closed. It is on a 22mm flow and return that goes to a heat exchanger at the bottom of the garden. This circuit hasn't been in use for maybe 8 years. I had checked for leaks at the heat exchanger late last night and walked along the pipe run. I knew that because of our water table being so high in the rear garden that any leak of this size would be clearly visible.
Anyway, looking along it today I lifted a section. A JG plastic connector had come apart, presumably in the recent very cold temperatures. Underneath the pipe was a hole that had channelled all the water under the fence into next doors 'garden'.

I think I must have knocked the valve when I put the christmas decorations away!


Thanks again for your help, your much more helpful / less rude than the people on the electrical forum

 

[Mdljk]

I'm joking.

I thought I'd check the where all the boiler pipes come up from the boiler into a crawlspace. I noticed that a motorised valve was open that shouldn't have been, it should have been closed. It is on a 22mm flow and return that goes to a heat exchanger at the bottom of the garden. This circuit hasn't been in use for maybe 8 years. I had checked for leaks at the heat exchanger late last night and walked along the pipe run. I knew that because of our water table being so high in the rear garden that any leak of this size would be clearly visible.
Anyway, looking along it today I lifted a section. A JG plastic connector had come apart, presumably in the recent very cold temperatures. Underneath the pipe was a hole that had channelled all the water under the fence into next doors 'garden'.

I think I must have knocked the valve when I put the christmas decorations away!


Thanks again for your help, your much more helpful / less rude than the people on the electrical forum

You are very welcome. So it was a leak in the end but one that was hidden. Glad you sorted it out.

 

[Chuck]

there is no such thing as a stupid question

You must be new here.

 

[malx42]

Could be corrosion producing hydrogen

If it was hydrogen you could see if the gas burns as it’s vented from rad ...but highly unlikely in that amount.

 

[Tiggy1955]

Oh, and the CAPTCHA thing on registration doesn't work on 'What is next day after Tuesday?'

Hi,

I had a similar problem with water going back into the FE tank (I believe it's called pumping over). I fitted a new Grundfos UPS2 pump and (at the recommendation of someone on this forum) I set it to one of the "Proportional Pressure" settings. This fixed it and system works treat now. What is confusing though is why the system worked perfectly well for 20 years without this setting and suddenly started pumping over. I'm not a plumber or heating engineer by the way!

 

[Chris12345678]

I turned the pump back up to 3 today.
What’s the problem with that, pumping back into the f&e tank?

 

[John.g]

I turned the pump back up to 3 today.
What’s the problem with that, pumping back into the f&e tank?

Just to clear up a few items, you fixed the leak and and now there is no make up to the F&E tank with system off or on??
After this you had the pump running on speed 1 as suggested by someone above and everything was OK?. you now have switched to speed 3 and have you or have you not got a problem with pump back to the F&E tank??, don't know if you are having a problem with this or are you asking should there be a problem.
What make/model pump have you got?, if its a UPS 2 running on fixed speed 3 then I wouldn't be surprised at pump back to F&E tank or even pump back on fixed speed 2 for that matter.

 

[Chris12345678]

Hi, the pump is a Wilo Gold RS60.
I was asking if having the pump too high is likely to cause pumping back, is that the only problem with having it on too high a setting?

I’ll have to check!

 

[Mdljk]

Water can expand into the vent pipe as it heats up within the system but systems are not designed for water to be pushed up the vent pipe all the time the pump is working. Running a pump faster than necessary can lead to premature failure. A system may rely on the pump being on its max setting in order for all rads to get sufficient heat. But if that leads to pumping-over then careful balancing of all rads can help without increasing pump speed.

 

[John.g]

Hi, the pump is a Wilo Gold RS60.
I was asking if having the pump too high is likely to cause pumping back, is that the only problem with having it on too high a setting?

I’ll have to check!

Running on a high pump setting shouldn't IMO cause any major problems for the pump life, its better to have hot rads than to have a pump that only lasts for say 15/18 years instead of say 20!.

If you have a zoned system or if the rads are fitted with TRVs then while you may not get pump over/pump back with all rads open then you may get it with reduced flow rate which results in increased pump head and may cause it. I would suggest checking the F&F tank for pump over (under these reduced flow rate conditions) through the vent or pump back through the cold feed make up which would result in air being pulled in through the vent pipe, (“cold” feed pipe will be hot). If you are getting problems then turn the pump speed to 2 and see how you get on. Looking ahead to pump replacement time make sure you install a (A rated) pump that has a good number of PP (proportional pressure) AND CP (constant pressure) settings, a Wilo Yonis Pico 1-6 will give you all this but the choice is yours or your plumber, a CP setting may then be more appropriate in your case as you can maintain the highest pump head possible without getting pump over etc as the pump head will be maintained constant irrespective of the required flow rate, it will also give you the maximum head (without pump over) to help you with your “3 rads problem”.

Member Tiggy 1955 (post #77 above) had a pump over/back problem which was very interesting, if you read it through you may find it interesting/informative.

Air in CH system and hot water returning to FE tank via the cold feed

 

[Chris12345678]

Thanks.
Something to read in bed!

I have bought autovents for all the radiators now.
The Alladin Micro vent that screws into a 1/8” nipple looks a bit fragile if it gets knocked though?!

 

[John.g]

Thanks.
Something to read in bed!

I have bought autovents for all the radiators now.
The Alladin Micro vent that screws into a 1/8” nipple looks a bit fragile if it gets knocked though?!

Have you checked the F&E tank, I don't have the pump curves for the
RS 60 but any 6M pump running on speed 3 will certainly tend to pump over or whatever especially as zoning or TRVs shut off.