I recently had my combi boiler moved 3 metres up from a bedroom to the loft. Ever since then, every 3 days I have to keep going up to the loft and topping the boiler with water as it keeps loosing pressure and not providing any hot water/heating. I have tried to contact the plumber to sort this problem, we have eliminated that there is no leak so are at a loss as to why this is happening.

Do you have any solutions that we are able to try?

Kevin McCann, July 2009

Pressure loss is always caused by a leak. If there is no evidence of water then first thing to try is pressurise boiler to about 2 bar and turn on the heating. If the pressure gauge rises too much (above 3 bar) the boiler will discharge water through the presure relief valve (usually a 15mm pipe which points outside). If this occurs then the expansion vessel in the boiler will need to be re-charged with air or replaced if the diaphragm is burst. The pipe leadinding to the expansion vessel may also be blocked. Otherwise i'd be checking under the floor and the heating drain point for a leak.

Ian, July 2009