Glow Worm 30HXI?

Hi Everybody

Our boiler has decided not to fire up at all. It had been starting up intermittently over the last few days, but now nothing except some ticking noise every few minutes.

When it was firing, the fan sounded like it was fluctuating as was the burner. Sometimes the burner would go out but the igniter would kick in and everything would start up again.

I have had a local plumber round, he has checked all the usual things, the pump is working fine, there is water in the header tank, burner has been opened and cleaned. He tried running without the thermistor and flow meters but still the same problem, it just wont fire up now. I have also disconnected the condensing pipe and put boiling water down it to clear it up as it is snowing right now, but still no luck!

Any ideas from anybody?

Kindly