DIY Doctor UK DIY Forums

When i put a call in for DHW or CH everything starts ok but the burners dont fire up, there is a spark, i have replaced the gas valve and flow sensors, could it be the PCB?
Any help would be great thanks

You need to see if gas is passing through the gas valve, you need to put a gauge on the inlet and make sure you have gas going in, then see if there is any pressure rise on the outlet when it is attempting to ignite, go to the ferroli wbsite and look at the instructions, you have to set your gas pressures after replacing the valve.

You might find this useful.
After several years, I finally bottomed the problem on my Modena 80, which kept shutting down when running DHW.
The overheat stat on the upper left hand side of the heat exchanger was operating at around 50 deg, instead of 100. It's actually a mechanical device operated by a bi-metal pad - The excess force of the spring clip used to mount it pushed in the face plate in slightly, causing it to switch off at a much lower temperature than it should.
I broke it while messing, and the boiler wouldn't fire up - Fan came on then instant lockout.
Careful when renewing this - It operates at 240v.

You might find this useful.
After several years, I finally bottomed the problem on my Modena 80, which kept shutting down when running DHW.
The overheat stat on the upper left hand side of the heat exchanger was operating at around 50 deg, instead of 100. It's actually a mechanical device operated by a bi-metal pad - The excess force of the spring clip used to mount it pushed in the face plate in slightly, causing it to switch off at a much lower temperature than it should.
I broke the stat while messing, and the boiler would not operate - Fan came on, then instant lockout.
Careful when renewing this - It operates at 240v.