Loads of air in central heating.

[Chris12345678]

Preferable to an unfloor (buried in concrete) leak

 

[Mdljk]

Is there any sign of water under the boiler itself?

 

[Chris12345678]

Is there any sign of water under the boiler itself?

No.

 

[Mdljk]

Has anyone done any plumbing work anywhere in the house on anything?

 

[Mdljk]

..... around the time this first began

 

[Chris12345678]

I’ve remembered:
Only thing I did was fit two Z-Wave thermostats (just changed the plastic part of the TRV, didn’t change the actual metal valve), at the beginning of December.

And a few months back I put the CH pump from speed 1 to speed 3.

 

[Harvest Fields]

The pump on 3 might be the issue.

 

[Mdljk]

The pump on 3 might be the issue.

Agree. Try turning down to 1 - temporarily - and wait to see if this has any effect. TRV heads are not an issue.

 

[Harvest Fields]

Why did you turn it from 1 to 3?

 

[Chris12345678]

I changed the pump years ago, at the time I didn't realise it had different speeds. I was trying to improve flow as three radiators are always a bit slow to warm up, they are on the same leg.

 

[Chris12345678]

I held a bowl over the flue for maybe 30 seconds this afternoon, and this is what was in the bowl.


https://i.*********/PwP5IfZ.jpg

https://i.*********/uYVNOtG.jpg

 

[ShaunCorbs]

That’s fine

 

[Mdljk]

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?

 

[Chris12345678]

That much water from the flue is ok?

 

[Mdljk]

Yes.

 

[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.