My CH combi-boiler is constantly losing water pressure, at up to 1 bar every
couple of hours.
I can't find any obvious leaks and there's nothing from the
Would I notice a leak of this size as a damp patch on a floor or ceiling? Is
there anywhere else it could be disappearing to? All pipework is above the
It could be leaking into the boiler itself. If any pipework is passing
through a cavity wall or behind dry lining plasterboard, the leak may be
running through to under the house.
Is there a lot of steam coming from the boiler when it starts?
I haven't noticed any steam although I've only been next to it as I've been
filling up when there would be signs of life.
Or do you mean from the exhaust pipe? I probably wouldn't be able to tell
whether there was an unusual amount of steam.
The boiler is newish and is upstairs in a converted bungalow and from what I
can see the pipes are mostly in the ground floor ceiling, and run down the
nearest corner to each radiator downstairs.
(The house is rented and ultimately the boiler is not my responsibility, but
it would be nice to pinpoint the problem first.)
If it's a condensing boiler and the heat exchanger is leaking, it
could be running away unnoticed with the condensate down the drain.
If it's not a condensing boiler, such a leak will normally end up
running out of the boiler casing as their combustion chambers
chambers are not normally sealed completely water-tight.
Does it only lose pressure when the system is operating and hot,
or does it also lose pressure when the boiler is not being used?
Does the pressure go right to zero if not repressurised, or does
it just drop to a certain level and stay there?
[email address is not usable -- followup in the newsgroup]
I'd have to do an overnight test to answer that. I'd say it loses pressure
even when off, but:
I don't remember seeing the pressure guage below about 0.4bar, and as it
happens the minimum operating pressure is 0.4bar, according to the manual
I've just downloaded.
The boiler is an Optima 701 (a combi) and haven't noticed water anywhere
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.