The cam is powered by the live feed, usually from the boiler thermostat. First check is that the flue stat, or flame sensor is in the cold position, then it powers up the glowcoil, after a period it opens the solenoid. When the flue warms up, the flame sensor changesover and the cam stops. If no flame, then the cam continues and switches off the glowcoil and solenoid. Recon units are available from Peter Porter Ltd in Hertfordshire.
Thank you OILHEAD, that explains a few anomalies, need to do a bit of conning but it seems that although the control box is 'live' the boiler circuitry is dead despite having power at the round 3pin plug which explains the lack of control to the motor.
Presently, the 2nd and 5th (from the top/away from the motor) microswitches are depressed and if I operate the top m/s, ignition takes place and if the 4th m/s is held closed, the fan rotates and the fuel ignites and the boiler runs 'normally' after releasing the ign m/s.
While the boiler is running in this configuration, the cams are not rotating, the control box and panel neon lights are still off, operating the boiler stat and the flame stat makes no difference and even unplugging the round 3pin plug has no effect. The boiler will run until the 4th m/s (fan) is released.
If the boiler stat is dead (open cct) would that cause all the above ?
Have to do a bit more digging behind the panel before I start to panic or freeze over.... brrrrrrr...
Thank you again and will keep you posted