Boiler losing pressure

joncarpet

For about a week now, our boiler has been losing pressure.
In the morning (6am) it is between 0 and 0.5 bar, so I top it up to 1.5 and over the day in slowly creeps down to 0.5 ish and needs to be topped up about 6pm.

The boiler is a Main 24 HE condensing boiler and has roughly been in for 3.5 years.

any ideas as to what is wrong and how much it will cost to fix would be greatly appreciated.

joncarpet

cheers for the reply.
radiators seem fine, as does under the boiler.

Is the pressure relief pipe the thin copper pipe?
If so, nothing leaking from that.
However, there is some dripping from the white plastic pipe that comes out the boiler, through the wall and into the drain.

i_love_it

I had this with my old boiler. Then i had a new boiler installed.
It happened again last year during the really cold spell so i had the installer back to check everything.
No signs of a leak, though the installer said a full investigation would be costly as it would involve ripping up floors to fully check all the pipe work.
He said if a leak was present vast amounts of water can be soaked up in woodwork without ever showing signs externally.
He did put some solution into radiator pipes to bond a possible leak and it hasn't happened since.

He just went out to B&Q to buy the bottle of stuff he poured into the ratiator, I don't remember the price exactly as he didn't charge me, but i think it may have been around 20.00

keystone

Check your expansion vessel. There is a Schrader Valve (like on your car tyre) on it. Press the pin in the centre and if air comes out recharge the expansion vessel with a bycycle pump. If water comes out then the diaphragm isn't very well and youll be needing a new EV.

Cheers

welda

If CH pump has pump valves either side, exspecially valve type where you open/close valve using screwdriver or allen key, after a few year, this type do tend to leak around area where you insert screwdriver or allen key.

If it is the above, replace with gate valve type.

:beer:

joncarpet

We've just had someone out to look at it and they couldnt identify what was the problem. Its either:
- a leak somewhere. two bottles of leak stopper thingy and an hours labour, plus fingers crossed that it works. It might not!
- a faulty secondary heat exchanger. £140+vat and 4 hours labour.

none of the possibilities mentioned above were mentioned.