Combi low water presure and leek out of presure releaf pipe

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Hello folks - i have a glow worm compact 100 combi (9years old approx)
water presure keeps droping so top up via loop, checked for leeks found none then noticed leeking out side via presure releef pipe. also did notice when heating on presure above 3 bar
Any advice much appriciated - Cheers
 
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YELLERBELLY

Hello folks - i have a glow worm compact 100 combi (9years old approx)
water presure keeps droping so top up via loop, checked for leeks found none then noticed leeking out side via presure releef pipe. also did notice when heating on presure above 3 bar
Any advice much appriciated - Cheers
see faq no.18
 
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Not an expert but probably faulty/needs a top up expansion tank and possibly prv. You could try dischaging the PRV to blast out any crud which may be holding the valve open. If the Expansion vessel needs a top up then that will be the cheapest/best result
 
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where do i find F A Qs #18 cheers Will p/s i'm new to this site

18 ) WATER IS COMING OUT OF BOILER'S "PIPE" Thanks To ChrisR

Combis (and other boilers) have a metal Pressure Relief pipe going out through the wall, sometimes wrongly referred to as the boiler's "Vent" or "Overflow". For safety it is usually turned back to the wall or taken to a low level. This is the Pressure Relief Valve and is an important safety feature. PRVs in boilers nearly always have red tops. Old Vaillants are grey.

It can be seen leaking water because:

1) The PRV has been opened (perhaps to let water out of the system) and it has failed to shut properly. This is because dirt gets stuck on the valve seat. You can try to twist the valve and it may "clunk" shut but it can make the leak much worse.

2) System pressure has gone above 3 bar and the valve is doing its job releasing boiler pressure. This is often due to the boiler's pressure vessel needing attention.

3) The pump may have failed.

ANY Pressure Relief Valve which has let water out is likely to need replacing!

Water coming out of a white PLASTIC pipe will be from a condensing boiler and is normal. It must go to a drain and not allowed to dribble on the ground!

4000_3451_18823_14178624_thumb.jpg

Hope this helps
 
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expansion vessel may have failed, if pressure is a above 3bar the pressure relief valve will activate (dribble out of pipe to outside). is pressure below 2bar when cold? if so i would check vessel first.
 
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Shouldn't you be dropping that strap line by now bster. You've been in the game long enough haven't you?
 
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Thanks bster - When cold pressure below 1 bar !!(but now when running wont go above 3 bar) seems that when i set pressure between 1 and 1.5 cold then it will go above 3 when hot. to be honest this boiler has always lost presure every year when you start using the heating again i would have to release air from upstairs radiators and add water to get presure right !!??
-- Is the vessel easy to deal with or complicated ?
Cheers Will.
 

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