I live en France and have a Lamborghini/Calor oil boiler, this has a Danfoss BFP11R3 pump and a Landis & Gyr Siemens LOA24171B27 control box together with a Landis & Gyr photocell. Boiler is about 8 years old. Had a bit of an issue earlier in the year as temprature fell to minus 25 and the fuel supplied here gelled, had to resort to using 20 litre cans with the hoses put in and the suction of the pump to run the boiler, all worked fine as it was only in use as a back up for the wood boiler. Couple of weeks ago the wood boiler developed a fault and the oil boiler was switched on, now reconnected to the main tank, had been run after this reconnection without problems; boiler fired and after half a minute or so went off, waited the prescribed preset time and fired up again, half a minute and off again; tried this a fem more times and decided to pop the spare burner in and it fired up and runs fine. Now have the rogue burner on the bench and have tried to isolate the problem, have checked the solenoid with an external power supply and it magnetises and holds, have checked the photocell and all seems ok and inded have tried a new unit, have tried the control box from the working burner. What I now have is thus, with the benefit of the external power to the solenoid the burner will ignite immediately this power is switched on, runs for half a minute or so and then the flame dies, I imagine the spark stops sparking as there is still evidence of oil. Wait for the unit to reset, press the button and off we go again to the same scenario. Incidentally I have a different make unit with an almost identical problem, only difference is that this unit will continue to run with the benefit of the externally energised solenoid; both units developped the fault at around the same time! Any thoughts?