when i switch on boiler not a lot happens, first i thought it was the pcb board but thats not the problem, tried different air pressure switch but no good.... one thing i did notice is if i take tube off air pressure switch and blow into it the fan comes on and boiler starts up and runs fine until it reaches temp but then it wont start up again unless i blow on pressure switch again, also their is no voltage to fan until i blow on air pressur switch, i would have thought the fan needed to come on first to activate the air pressure switch ????

john, March 2011

tks Brian double checked that and their is only 240v at 2 white when i switch boiler on but if i blow on in air pressure switch their is 240v at 1,2 and 3... boiler starts up in correct order i.e fan comes on, solonide valve clicks open and pilot lights then a second or two later main solonide valve opens and boiler runs fine up to temp, once it closes gas valves it will not come on again until i blow on air switch ? as i say pcb or air pressure switch are not faulty

john, March 2011

there are three wires to the pressure switch white 1 or NC orange 2 or NO brown 3 or C with the fan off 3 + 1 should be live with fan on 3 + 2 should be live if not possible problem with gas valve or pcb

brian, March 2011