Oil boiler lockout.

[StewartA]

Worcester Bosch Danesmoor SLPJ 20/25 Oil boiler with conventional flue; Santronic TF830.2B controller; Fully serviced and cleaned (including cleaning flame detector and nozzle chamber) – which had no impact on the problem; Oil supply OK. The system only has a room thermostat and a boiler thermostat, hot water tank is gravity fed, central heating pump is working OK.

Sometimes the burner locks out, sometimes it works all evening OK before locking out. I have tried a spare replacement controller which did not cure the problem – so not thought to be a controller problem.

Situation detail (a): burner fires up; room thermostat is closed (set high for this test); burner runs for some time; burner flame cuts out; burner blower continues for 10-20 secs, during which time some rapid relay activity in the controller for 1 second or so and then locks out and blower stops. The lockout only occurs at the end of the burn cycle.

Situation detail (b): burner fires up; room thermostat is closed (set high for this test); burner runs for a few minutes; intermittent rapid relay action in controller; burner and blower cut out.

Any ideas about the cause of the problem please?

Thanks

 

[dcawkwell]

Replace solenoid and solenoid valve at the pump.

 

[StewartA]

Thanks for your prompt reply dcawkwell.

I'm not an expert on the burner unit, but is there a solenoid? I see a transformer, motor/fan. control unit and oil pump, which feeds the nozzle assembly - but no solenoid. Is it integral with the pump, or have I missed seeing it?

Thanks / StewartA

 

[Burnerman]

The solenoid coil is the main culprit, sitting on the top of the oil pump......held on by one allen nut, 3 wire electrical plug going into it.
Costs around £30. Part number 071N0010, for a Danfoss BFP pump.
John

 

[StewartA]

Thank you Burnerman.

Part ordered - should be fired up in next day or so.

Regards
StewartA