Losing 1bar pressure every day

[Danny1234]

Would appreciate any help before calling out central heating engineer.

GlowWorm 12hxi condensing boiler has been losing pressure. Every morning pressure is at 0bar so I top up to 1bar cold.. Fire up boiler works ok but pressure drops down to 0 bar throughout the day, this has been going on for about 1 year. Cable tied bag over PRV outlet pipe left it there for 3 weeks totally dry so not a problem with PRV leaking. I have access to every inch of pipe work, both when boiler is running hot and cold I have visually looked for leaks but found none. Boiler loses pressure even when not in use. I can top up pressure to 1.5bar in the morning, not switch boiler on for a whole day by next morning back to 0bar. I once repeated topping up boiler every day for two weeks when not using central heating to see if I could find any wet/damp patches on any rad/pipe joins or around boiler but found no sign of leaks. The other day I disconnected the condensate drain pipe where it connects to my sink waste I placed the end over a bucket, pressurized the boiler to 1.5bar did not fire up boiler left it switched off. Condensate drain pipe started to drip water. I calculated that about 700ml of water was coming out of condensate drain pipe in a 3 hour period. My question is should the condensate drain pipe leak water if the boiler is not in use and had not been in use for a 24 hour period. Could this also be responsible for the pressure loss?. I’m also getting a lot of air in system.

Any help would be greatly appreciated
All the best
Danny

 

[michael c]

Yes it could be as condensate only accumalates when boiler in use you will need a gss to look for you though as you will probably have to disturb seals to check where its from. Sorry but forum rules say thats all i can advise.

 

[bewsh]

The boiler shouldn't have any water coming down the condense pipe if not in use. When you say not in use though, was it just the heating not in use and the water being on? Also if it was raining and rain water was coming down the flue then the water would make its way down the condense pipe.

 

[diamondgas]

:welcome: to the forum Danny 🙂

With every top up you're diluting the anti-corrosive and adding fresh, oxygen filled' water to eat away at the inside of the system Danny!! If it is system water coming out of the condensate then you're in for a hefty bill to repair, alas. I'd seriously consider getting onto a service and maintenance contract with one of the big boy's!!! Maybe mention a month or two into the contract what your issue is 🙂

 

[Danny1234]

The boiler shouldn't have any water coming down the condense pipe if not in use. When you say not in use though, was it just the heating not in use and the water being on? Also if it was raining and rain water was coming down the flue then the water would make its way down the condense pipe.

Both heating and hot water not in use when water dripping out of condensate drain pipe , also not raining outside so not possible for water to enter flue.

Thanks for your reply

 

[Danny1234]

Both heating and hot water not in use when water dripping out of condensate drain pipe , also not raining outside so not possible for water to enter flue.

Thanks for your reply

 

[dancinplumba]

Both heating and hot water not in use when water dripping out of condensate drain pipe , also not raining outside so not possible for water to enter flue.

Thanks for your reply

you hex is buggered then, call a qualified heating installer to sort it for you 🙂

 

[bewsh]

As above. Probably quite a pricey job mind, these heat exchangers aren't cheap.

 

[Danny1234]

Thanks for your input and advice much appreciated. I suspected boiler was knackered because I couldn’t find leak anywhere. Will get someone qualified to look.

 

[StillLearnin]

Sounds like Expansion vessel ..... get someone qualified to look properly.

 

[villa_tom]

Sounds like Expansion vessel ..... get someone qualified to look properly.

You sure???

 

[REDSAW]

You sure???

its a big one🙂

 

[Mike Jackson]

Sounds like Expansion vessel ..... get someone qualified to look properly.

Obviously not learnt enough yet or not read the whole post.

 

[StillLearnin]

9 times out of ten.... they can leak on the seams, dribble down the combustion chamber (externally) and appear on the condensate pipework.... obviously depends on boiler layout. Needs checking properly though as could obviously be more serious.

 

[PlumbBobBob]

or indeed 'still learnin'

 

[Mike Jackson]

9 times out of ten.... they can leak on the seams, dribble down the combustion chamber (externally) and appear on the condensate pipework.... obviously depends on boiler layout. Needs checking properly though as could obviously be more serious.

I've only seen one leaking expansion vessel in a boiler in over 30 years and that was when someone inadvertently connected cold mains to the discharge pipe under a caravan.

 

[michael c]

you hex is buggered then, call a qualified heating installer to sort it for you 🙂

Wasn't sure if i was allowed to tell them that

 

[diamondgas]

Wasn't sure if i was allowed to tell them that

If you weren't then a 'mod' would have edited and slapped ya wrist mate! :lol: