You help would be very much appreciated........I have noticed water dripping on to the floor underneath my boiler and it is tripping the board.

I have taken the front cover off and the silver cover which covers the main components of the boiler. After looking at the very old instruction manual, I can see water dripping out of the 'automatic air vent' which is dripping down onto exposed wires and causing the electrics to trip at the board. It looks like the automatic air vent is missing a screw to stop it from leaking because I can see the thread inside of the hole where the water is leaking from.

Could you please tell me if i am right and if i bought a screw for it, does it have to be tightened or partially tightend with it being automatic air vent?

Many thanks

James, April 2011

Update: Replaced the AAV tonight with a Bosch genuine part. No leaks, electrical cut-outs!!! Water and central heating piping hot. I have saved an absolute fortune by doing this myself and having a little common sense.

Boiler working just fine now..........

Thanks to Carefree for his advice.

James, April 2011

thank you carefree.

James, April 2011

The Automatic air vent is probably missing a plastic cap. However, if this cap was present it should be loose anyway.
Your only option is replacement of the AAV if it is leaking.

Carefree, April 2011