My boiler is dripping from a Blue screw on cap, which is underneath a square-ish White Plastic Vessel, which is visible at the top rear behind the control panel, there is another pipe connected to this which goes outside. I have manged to tighten this cap up and the drip has reduced. What does this do and is it easy to replace (will my garage fill up with water if I remove the Cap)

Thanks Pete

Peter dyson, February 2008

To Paul the gas man.

Thanks for your prompt answer, I have managed to tighten the cap a bit more and the leak has stopped, I'm sure it start away at some time in the future, in which case I will remove the cap and cheak it out. I have checked the upper part of the cabinet and there are no leaks there from the boiler.
Again, many thanks

Peter, February 2008

the blue cap can easily be replaced, but when you remove it about 1/2 pint of water will pour out. the water may not be comming from the cap. it is more usually due to a leak insde the boiler running out the hole in the case under the condensate trap and dripping off the blue cap.

Paul the gas man, February 2008