Central Heating Leak

Mr_Ted

;)and check the connection to the EV isnt blocked to remember;)

50Twuncle

:A

keystone wrote: »

Have you checked the PRV outlet? With that sort of loss then, if it is the PRV, the bag is probably not necessary. You'll be able to see that the wall/ground is wet and feel the water in the open end of the pipe. Can you?

Yes I did. Possibly not that then. I got the impression from your other posts that it was much more frequently than that. Another test for the EV. When you have the pressure at 1 - 1½ bar and then turn the heating on does the pressure suddenly shoot up to approaching 3 bar? If it does thats the EV gone and if it does go that high then the PRV will have lifted anyway.

OK. I'm probably going to regret this but there is a way you can check the HEX even though I said there wasn't because I suspect it would be better if your heating engineer did it for you. This evening pressurise to 1 - 1½ bar. Turn boiler off. Isolate the boiler by closing the valves on the flow and return. Go to bed. In the morning check if the pressure has fallen. If it has then the leak is internal to the boiler.

Cheers

Does the PRV check need the heating running?

50Twuncle

OK have checked the outlet pipe - dry and clean
What next ?

keystone

50Twuncle wrote: »

:A

Does the PRV check need the heating running?

No

50Twuncle wrote: »

OK have checked the outlet pipe - dry and clean.

Good that's one item off the agenda then.

What next ?

The other items?

Cheers

southcoastrgi

It's dry & warm outside so if you just went out & checked then it might have dried up, did you put a bag over it as KS suggested, this is the first thing to do, then if there's no water in it after 24 hrs then follow KS advice & isolate the boiler & see what happens (you won't be able to use the boiler during this time)

Still waiting for the answer to my question, how did they re-pressurise the EV ????

macman

The PRV ppe may be dry, but the ground beneath it may show signs of recent discharge. Did you check??

50Twuncle

macman wrote: »

The PRV ppe may be dry, but the ground beneath it may show signs of recent discharge. Did you check??

Yes - it is above clean dry concrete and I have checked the pressure this morning on the boiler and it is down to ZERO - that is without the heating running !!

Which implies to me that there must be a big leak in the pipework ......

(My Plumber on Tuesday - "closed an airvent" in the boiler - whatever that is / does...)

If there is "any" problem with the PRV or Expansion Vessel - surely, the water has only one place to leave the boiler from - the discharge pipe ?
And if there is nothing coming out of this pipe - it does tend to imply a leaking central heating pipe - but where ?
From the amount of water loss - it should show, by now, if it is on the 1st floor (damp on ceiling) - but no signs.
So, As I suspected - it must be on the ground floor - so it looks like the next step will be to lift carpets and floorboards and start looking ...
Finally - I take it that it is safe to run the water heating side of the boiler, with no pressure (no water ?) in the central heating side of the boiler ?
ie) They are separate circuits and the lack of water will not "burn out" the heating heat exchanger ?

ValHaller

50Twuncle wrote: »

So, As I suspected - it must be on the ground floor - so it looks like the next step will be to lift carpets and floorboards and start looking ...

You are determined to lift carpets and boards and who are we to stop you?

Myself, I would take the handles off all rad valves - both sides of the rads - and check the gland nuts. This is a favourite place for small leaks and the tell tale is a small encrustation around where the valve spindle enters the gland. Sometimes you can tighten the gland nut up a bit, which will help, but overall, once you need to do that, the valve will be back to leaking sooner or later, so you will need to keep an eye on it.

50Twuncle

ValHaller wrote: »

You are determined to lift carpets and boards and who are we to stop you?

Myself, I would take the handles off all rad valves - both sides of the rads - and check the gland nuts. This is a favourite place for small leaks and the tell tale is a small encrustation around where the valve spindle enters the gland. Sometimes you can tighten the gland nut up a bit, which will help, but overall, once you need to do that, the valve will be back to leaking sooner or later, so you will need to keep an eye on it.

But there are no signs of any water leaking from any of the radiators - they are all dry as are the carpets under them
This must be a big leak - with the pressure dropping from 1.5 to zero bar in 48 hours !!

southcoastrgi

what the make & model of the boiler ?

& for the third time how did they re-pressurise the expansion vessel ?