Can anyone help me as I am paranoid my boiler is going to blow up every time I put the heating on, so I am now not putting the heating on and it is freezing!! Last week we bled our radiators as they were all very cold at the top, and the pressure on the bolier went right down to about 0. We had a plumber in the flat at the time and he managed to adjust the pressure, although I think increased it a bit far, so it was at about 3.5 bar. He suggested we needed to let some more water out of one of the radiators, which we did, and the pressure went down to about 1. Problem is that although the pressure is at about 1/2 when the heating is off, as soon as we put the heating on the pressuree raises to over 4 (off the scale). Is there anything we can do to mend this, or do I need an engineer? Thanks!

im, December 2008

Hi
There should be presure release valve which should let off extra presure, so the boiler dosent blow up. However if your presure range is that great ie 0.5 bar when cold upto 4 bar when hot then you have a problem with the expansion tank, either it needs recharging (pumping up with air using a bike pump) or the diaframe has split (new tank needed) either in the boiler or if its to hard to get to you can fit an external one. do a seach on google for boiler Exanstion tanks.

Dave the Rave, January 2009

sounds like u need your precharge in your expansion vessel checking@.75bar.

don, December 2008