i am running h/w /c. heating from a vaillant boiler, but seem to constantly get an air lock which drones. i have pushed more water in, released water from the pressure release at the boiler, which only offer temporary help. i am not aware of any leaks around my system. how does the air release valve work at the top of the boiler? has any one got any ideas where else the problem might lie???

andrew, March 2007

Turn you boiler off so that the pump is not running,fill the system to 2 bar and manually vent all rads on the system.Do not vent using the pressure relief as this will cause you problems as this is an emergency feature as should not be messed with.The boiler should then be turned on and the system run for an hour or so, the boiler will vent any air trapped through its own auto release valve.

Andrew Turner, March 2007