How serious is it and what can I do to fix it?
On my Potterton Lynx 2 combi boiler for heating and hot water a red light comes on under low system pressure when the heating goes off and cools down and the heating will not work. What can I do to get it working please?

Marie Casey, November 2007

repressurise system as said before and vent accordingly, also there may be an expansion vessel problem especially if you are losing water outside through the 3 bar pressure releif valve, just check outside and see if the pipe is leaking, you may also have a blockage on the pressure gauge

lee, November 2007

Fill the loop by the valve tap underneath until you get 1 to 11/2 bar pressure, run the boiler and air off all radiators starting with the lowest radiator in the system.
This should help ,if not get it checked as it will be losing pressure somewhere!!

Tim Hutton, November 2007