Worcester RSF 280 - Main Burner not Firing

Hi,
I have an 8yr old worcester RSF 280 and currently no heating or hot water.
I've been through the fault finding chart for both heating & hot water. All voltages are present, diverter valve is operating, pump runs, fan runs, ignition sparks every time and lights the pilot, which stays on. The main burner does not ignite. The fault finding chart points to the gas valve solenoid as being the problem Is this likely to be the case, as I wouldn't like to purchase one and find that that is not the problem as they appear to quiteexpensive (£125). Any advice would be much appreciated. Thanks

seems like either valve or board.not sure but is there a pilot sensor .

Have you had or done any electrical work in the house in the last few days?

Can you hear the ignition sparking even though the pilot is lit?

Stan

You can measure the resistance of the second stage gas valve solenoid. If its o/c then it will not work.

If its OK then you can measure to see if there are volts applied after the pilot has been ignited.

If no volts applied and the ignition carries on sparking then it might be the PCB or ignition lead at fault in not detecting the flame.

Replacing the gas valve should be done by a competent person who is normally CORGi registered. Its not just a simple matter of plumbing it in! It has to be carefully set up to give the correct min and max gas pressures and tested for any gas leakage.

Tony