B11 oil burner troubleshooting

[Rossbraithwaite]

Hi, thanks for reading. I have a Worcester Bosch Heatslave 20/25 fitted with an Inter B11 burner. Yesterday the whole boiler was dead including the control panel. I replaced the control panel fuse which had blown. The Control panel came back to life and the fan started and just ran and ran. I checked fuel supply, ran motor with bleed valve open, there is definitely fuel there. There was no smell of unburnt fuel while the fan was running. Would you suspect the solenoid coil? Is this an open/shut valve for fuel flow into the burner? If that has failed will the control box not allow a spark?

 

[jeff the gasman]

Is it sparking? Check coil resistance!

 

[Rossbraithwaite]

I don't think it is sparking but is just audible is there any other way to know? So if the coil has failed the resistance will be low? what should it be roughly?

 

[Johntheo5]

I have a 17 year old firebird with a Riello burner but it has a 50V control box and I think the coil (even though have never had to replace any item of the Riello G5X burner, resistance was ~ 100 ohms.