Combi boiler leaking water

[RichN]

Hope someone can help...

I've got a Ferroli Optima combi, I've drained the central heating and replaced all of the radiator valves with TRVs. Come to repressurise the central heating (something I've already done 2-3 times over the past 2 yrs with no problems) and it pressurises, the TRVs are all fine (no leaks!) but water leaks out from inside the boiler, a pint or so over 5 minutes. Depressurising things stops the leaking.

I've taken the front panel off to have a look. There's a copper barrel, about the size of a coke can but a little thinner (pressure expansion vessel?), on the boiler side of the filler circuit. On the top of it is a brass barrel a bit bigger than a cotton reel, on top of this is a small threaded nipple with a couple of o-rings at its base. Looks like it should have a cap but there's nothing there. This is where the water's coming from.

Does anyone have any ideas what may be wrong? I'm not intending to fix it myself but I want to have an decent idea what the problem is before I get a 'professional' in to fix it.

Rich.

 

[bripl]

from your discription it sounds like the aav try acar/bike tyre valve dust cap as a TEMP REPAIR.the aav needs replacing

 

[RichN]

Uh, thanks, but AAV? I'm guessing the V is for Valve?

Rich

 

[breezer]

think he means Auto Air Vent

does yours look like

this is an Auto air vent

 

[oilman]

It's not really on its side. This is breezer's old picture that has fallen over.

 

[RichN]

Sort of. I've taken a picture of the one on our boiler. Apologies for the quality - I couldn't get the camera to focus properly. The bit that's circled is where the water's coming from. Loks like the whole of the brass barrel can just screw off and a new one screw on in its place. Is it really that easy?!

Rich.

 

[RichN]

OK, how do I add a picture?