Plumber left the boiler running at 2 bar but within 24 hours it had risen to 3 bar with water dripping from the overflow. It has been like this for 4 months now. This morning it suddenly rose to 4 bar (well into the red zone) when both water heater and heating on. When switched off pressure returned to 3. What do I do?

Puzzled, June 2009

Thanks Mr K, will try what you suggest.

Puzzled, June 2009

You can remove the water from drain cock if fited one or remove water from radiator air key to remove extra water and bring pressure 1 to 1.5 the system to be cold when doing this. If still continue to do this than you need to repressurezed the expension vessel to 0.9 Bar and than check and it should be done with system pressure to 0bar.

Mr K, June 2009