Hi,
help
we have an old Monoflame Minor burner, with a Danfoss pump.
Changed the pump, coil, and motor two years ago, and been fine until now.
It will run for 2 or 3 minutes, then cut out. The oil has got low recently, but it's been re-filled.
I have bled out all the pipes, checked the filter in the pump, there is 240v going to the pump coil, the photocell is responding to the light ok on a voltmeter, and it sounds like a healthy flame, until it stops, and goes into lockout. The coil has 240v on it until lockout.
Has anyone any suggestions?
Thanks

Mike, May 2009

Thanks for all the responses. It was the solenoid, not sure which bit, probably the coil. The cost to replace the pump was about £30 more than the coil, so I swapped the entire pump out, it's been fine since.

Mike, June 2009

Change the Oil pump Coil these are notorious and drop out as the coil winding heats up

www.elanar.co.uk, May 2009

Hi,
it's the control box locking out, not the overheat sensor. No excessive soot, or smoke. worryingly, the only filter I can find is the one in the pump, but then again, this did look clean. It re-lights ok, but then shuts down after a few minutes again.

Mike, May 2009

If you want me to hazard a guess, check the coil resistance just after lockout occurs. They are available separately from the pump.

John, May 2009

You would think that a run of 3 minutes would be ok, wouldn't you? I'm wondering how long it has been since the boiler itself was cleaned out - including the flue baffles? Sometimes the boiler has an overheat sensor that is triggered by a sooty flue. Does the burner relight ok once you've pressed the lockout? Check the tank filter(s) for dirt or water, ensure that all valves are fully on. Any visible smoke at the flue? I think it would be good to test the pump pressure too, but at only 2 years old that should be ok.

John, May 2009