Combi Losing Pressure

[rayhool]

I have just moved to a new property and have a wourcester 24i combi. When I moved in I had to have the pump replaced and the expansion vessel re-infalted. Since then it seems to lose about 1/2 a bar of pressure every couple of days even when the central heating is not on. I have checked under the floorboards for leaks but cannot find any also it doesn't seem to be leaking out of the overflow, HELP!

 

[penpusher]

sounds like the schraeder valve on the expansion vessel is leaking. this is the car-tyre like valve, sometimes they don't seat correctly after recharging and leak air causing the pressure to drop, try using a soapy solution on the valve and see if it bubbles.

 

[rayhool]

Thanks for that. If this was the case would the overflow pipe not be leaking when I put the central heating on?

 

[Paul Barker]

Blow off drip? No? Blow off gush when system hot ? no? Martians are sucking it out.

 

[gasgeezer]

put a balloon over the prv discharge pipe see if it collects any water . also as it is not cold isolate flow and return valves on boiler in a couple of days open them if press. drops leak syst. side obviousley turn heating controls off.

 

[jiminblack]

Don't touch the flow and return valves on the CDi or you defiately will have a leak!!

 

[rayhool]

Thanks for all the replys. I got a plumber to look at it and he put some silicone sealer in the system which (touch wood) seems to have done the trick!

 

[COG]

Yes that will do the TRICK .Try looking in the combustion chamber on the top right you find the auto air vent and probably water stains below it ,if it was passing water before ( it evaporates out the flue)it will be full of silicone now so that means you have no vent to let air or steam from.

 

[rayhool]

I had actually had the auto air vent replaced when I moved in because it was leaking so this had already been checked.