Page 1 of Combi boiler - losing water pressure each night - help !

With the winter on us, I have found a fault in my combi boiler.

It is a closed water circuit and if the pressure drops below one bar on the gauge it switches of with an underpressure switch.

Each night it loses water so it switches off, i have to put in more water with the bypass lever each morning.

I have checked all radiator couplings and connections for any water weeps but nothing at all, checked when cold. (9mm mini bore piping), There is no air in the system, as I have checked,

Any help would be appreciated.

PS.. A workmate says there could be a fault in the boiler allowing water to escape from the closed circuit into the hot water circuit that feeds the hot taps, via the changeover valve from central heating.

Is this possible ?, i thought these two systems were seperate, although working from the one boiler.

This item was edited on Friday, 26th October 2007, 20:58

Cheeky Reply: You have a leak.

Sensible Reply: You definitely have a leak. Could be the boiler, my wife`s flat suffers from this albeit not daily, I keep telling her to replace the boiler as I have checked all the joints in the system. only other place is the boiler.

Doesn`t help you but...

Last week, we had a problem with our Baxi boiler central-heating system. Rang them up and they told us they could get an engineer out to look at it and they also sold us a £300 per year maintenance deal. The engineer turns up, takes a look at the pump in the airing cupboard and asks the wife if she`s got a hammer. Wife duly gets the hammer, engineer proceeds to tap the pump with it. Tells the wife to leave it for an hour and try it again. Engineer leaves. One hour later, we have a perfectly functioning system. Ring up Baxi and cancel the whole maintenance deal. £300 saved and not even a call-out charge.

Moral of this story - if at first it doesn`t work, smack the hell out of it with a hammer. :)

I`m with Bob-b on this, I suspect a leak, but it could be anywhere in the boiler/pipework or radiators.

Could be worse. I`ve just had to call someone out for mine and the main circuit board has went! 220+ VAT on top of the £75 call out charge.

I feel like crying! :(

"Life is like oral sex, one slip of the tongue and you`re in the s***!" - Roy Chubby Brown