Hi. The Worcester Boiler is 6 years old and was last serviced 2 months ago. It goes to "Lockout" when restarting, sometimes taking 6 attempts to reset. The sequence seems to go as normal with air purge, a click as a solenoid opens, but no sound of firing up. Afterwards, the fan runs for a purge cycle and "Lockout" appears. Any ideas would be appreciated.

Joe, December 2010

Check following:
Defective spark generator.....it has 2 x thick leads, which go into the nozzle area. You will need a replacement part to confirm .....replace and test for correct start up. If this defective, there will be no spark at all. Remove the burner and run a test, pointing the burner safely away from any people. Look down the blast tube and check if the electrodes are sparking.
Defective light sensing diode...again, you will need a replacement to confirm. If this faulty, the burner will fire up, for an instant, then stop.

david, January 2011