Johnny, your local gas fitter must really not want to come to your house! For £500 I'd fix your boiler AND your mother in law. Also I think your sister Gina should have won Eurovision - cheating foreigners!
it seems as though you have no gas going to the pilot, until this is lit and detected the main burner will not light.
1. Check the obvious; gas to the house? Meter valve on? Do other gas appliances work?
2. Check the gas isolation valve (bottom left corner of boiler) is open. It is normally never turned off, so if it worked yesterday it's very unlikely to have been (poltergeists, gremlins excepted)
3. If that doesn't solve it you are really down to checking the gas valve, and this is legally the domain of the CORGI registered gas fitter. There are two solenoid coils on it (there are also two makes of gas valve!), one of them switches on the pilot supply just before the sparking starts. Switch the boiler off, then wait 20 secs. Switch it back on and LISTEN. The fan will start whirring, and after about 10 seconds the pressure switch will operate with a quiet click. Immediately you should hear a more metallic clunk as the pilot solenoid energises, but I suspect you won't if it's broken!
If it is the gas valve you WILL need a CORGI reg'd fitter to fit it, look in yellow pages for a full page CORGI ad in the central htg section.
4. If no joy here's a long shot! When the boiler is ticking away trying to ignite the pilot try GENTLY moving the harness of wires to and fro at the gas valve end (you could say just a little bit, ooh ah, a little bit more...), then at the plastic plug end. It has been known for the PCB pins to be loose, if they are this action will get you a temporary result.
Let us know how you get on......PJ
Thursday, 29 September 2005