Please help.......anyone. I have a Vaillant Combi (inherited with house, no apparent model details). A few days ago, pressure had dropped to around 1/2 bar - combi has worked without fault fow four years. I subsequently increase pressure but had problems turning off valve (sticky lever) and as a result, pressure was increased to around 2.5 bar. I have tried to release some of the pressure which, initially does drop pressure to desired level however, after a few moments, pressure increases back to 2.5 bar again. I now have a leak from my outside overflow pipe which I have never had before. Has anyone got an idea how to reduce the pressure in my system and hence (hopefully), stop my leak outside????? My very pregnant wife is not a happy bunny at present so any advice greatly appreciated. Thanks Folks.
VAILLANT PRESSURE PROBLEM !!!!!!!!
- Thread starter DEANO79
- Start date
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If you trace the external pipe back to the boiler (it's not strictly an overflow pipe) you should find a valve. This is the pressure release valve. The reason that water is coming out of the pipe is that the pressure in your system is too high and the valve is letting the excess off to the outside world. They normally operate at around 3 bar.
The valve should have a twist cap (or similar) on it. Operating this this will lift the valve and let pressure out of the system.
However there are a few things that might happen/have happened.
Sometimes residue gets into the seat of the pressure valve and you get a bit of a drip from it afterwards (even though the pressure is OK - should be 1 bar normally).
Over pressurising the system may have caused a problem with your expansion tank. Once you have got the pressure back to 1 bar, if this rises to over 2 bar when the boiler is operating the expansion vessel may either need recharging or at worst my need replacing.
The pressure in the system can drop if you've bled the radiators.
Try this anyway - it may all be fine afterwards.
The valve should have a twist cap (or similar) on it. Operating this this will lift the valve and let pressure out of the system.
However there are a few things that might happen/have happened.
Sometimes residue gets into the seat of the pressure valve and you get a bit of a drip from it afterwards (even though the pressure is OK - should be 1 bar normally).
Over pressurising the system may have caused a problem with your expansion tank. Once you have got the pressure back to 1 bar, if this rises to over 2 bar when the boiler is operating the expansion vessel may either need recharging or at worst my need replacing.
The pressure in the system can drop if you've bled the radiators.
Try this anyway - it may all be fine afterwards.
check the filling loop is properly closed
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