i put pressure to 1.5 bar , turn on the heater , the pressure rises to 2. 5 bar and the safety valve lets by , , i have replaced the safety valve, when the boiler goes off , the pressure drops down to around 0.6 -0.8 bar , where the red fault lamp comes on, an the boiler wont restart untill i increase the pressure through thefilling loop valve, i have put a jar under the discharge pipe outside an get just under half a pintof fluid. can you help. saunier duval thermaclassic f30e faned flue combinationboiler

chris lane, April 2008

This is usually a sign that the expansion vessel inside the boiler has lost its air pressure...they are refilled using an ordinary car tyre pump to around 10 psi - or whatever the maker recommends.

John, April 2008