central heating leak
 

My central heating has sprung a leak. No tell tale signs and I was worried it would be carpets up, glued interlinked chip board floors up and or tiled floors up. Decided to undo the pipe from the pressure release valve, stuck my finger in and its wet. Turned the central heating up and put a towel underneath as the pipe was still detached and...... in minutes I am able to ring the towel out. I think I'm relieved.

Now to source a replacement valve, not sure which is correct so sent an email to Flamco with pictures asking for help.
My previous boiler at my previous house had its pressure release vale give up.

macafee2

You do know it’s illegal to interfere with a gas appliance unless you are Gas Safe registered Ian? . Our system has a slight leak, last time the boiler went down the engineer did a test and said the boiler was fine but a slight leak on the system. Gave me this foam spray and said let the system cool totally, take out a bleed screw from a rad,.spray this stuff in for 30 seconds, takes 28 days to circulate and seal any leaks.

Not gas, water :)

macafee2

Not illegal on your own property, unwise perhaps but not illegal.
Water side is ok If you know what you're doing.
If it's only the PRV and its a Flamco one, then it sounds to me like you've got a System only boiler as Flamco are a quality aftermarket supplier.
If you remove it and go to your local BSS, They'll most likely have one in stock.

I've replaced the pressure relief valve, emptied the expansion vessel, pressurised the expansion vessel and fitted everything back together. Re-pressurised the central heating and ran it for just over half an hour, it has now been off for well over an hour and it seems pressure is "holding". I have a slight weep on the water inlet so will disconnect that and try again but it is very very slight.

Never knew the expansion vessel should have been pressurised. Was then unclear about central heating pressure and expansion vessel pressure but that's now sorted.

Even a new expansion vessel is only about £30 so if that has also failed it is a cheap and easy change.

If this is solved then under £20 which is surprising as the web site showed the pressure release valve as nearly £50.

I'm well chuffed, the thought of carpets and floors up was stressful

macafee2

Sounds like a result, well done!

You would probably have had a nightmare trying to get someone in...

Hi, I too have a slight pressure drop on my oil fired c/h. I’ve been told most leaks are not to do with pipes underground, mines underfloor heating. You said you emptied the expansion vessel, if any water is in there, you need to replace, it’s an easy job.

why does the expansion vessel need replacing?
If you are going to tell me because there is water in it, that is not a definitive reason for it being faulty.
The water could be there because there is no pressure below the diaphragm and all that is needed is the "diaphragm" needs pumping up to give pressure below the diaphragm.
If however the air is leaking out be it via the valve or diaphragm then yes you are right, expansion vessel needs replacing but I need to prove the loss of air.

macafee2

Sorry to hijack this but my aunt’s house has a British Gas glow worm 330+ boiler and it displays the code f22; which means it needs filling with water, but there are no pipes exposed below or on top,of the boiler,so where is the filling loop? It is a condensing boiler and has a hot water cylinder in the airing cupboard. Could the fill valves be on there? Under the boiler everything is enclosed, there is a screw off panel but surely you don’t have to take that off ? Can anyone help? I have the instruction manual, but it doesn’t mention filling at all.

If it's the boiler I think it is, the filling loop is of the built in type, and should be revealed if you remove the lower panel.