Danesmoor lock-out?

it could be the fuel pump solonoid,sometimes there is a fault with them,when they heat up a certain amount something expands and breaks contact untill it cools sufficiently for it to make contact again.It is very easy to replace,connector plug on the end,and i screwed cap

John Buchan
October 2009

Thanks to everyone for their help. Fitted new coil and it works fine and I have saved a load of money. I am a little nervous working with these boilers, I used to design the control systems for large gas-fired industrial systems (100 - 500kW) so everything on these domestic boilers appears a little small and delicate.

Anyway it is now fixed and I know a bit more about how it works.

George G
August 2009

2min Job (for an Industrial Burner man!)

Undo the Brass nut on top of the coil, pull off the moulded electrical plug, get a new coil (about£30) and fit in reverse order, you get a new brass nut in the pack.

www.elanar.co.uk
August 2009

Thanks John and www.elanar.co.uk

Yes it looks like a solenoid problem, ignition is good (about 11 second delay), oil delivery is good, flame sensor has been replaced just in case. I have borrowed a plug-in controller and the same problem occurs.

Do I just unscrew the brass plug holding the solenoid onto the pump to release the solenoid? I am concerned that I may upset some settings as I don't know much about these boilers.

George G
August 2009

The solenoid actually switches the oil supply on within the pump....initially the burner fan will run to purge the boiler with fresh air - after about 8 sec ignition starts, together with the oil switch on. Thats why ignition isn't immediate.

John
August 2009

A good Service about £80 inc filter & Nozzle, Sounds like a new Solenoid coil will be required about £45, so at most should be about £150 to sort

Worcester charge a fixed price fee, which is good if you have a combi with a million leaks and faults, but in this case, you would be the loser

www.elanar.co.uk
August 2009

Thanks John

The combustion sounds good and even, I worked in industrial heating systems for years so I am familiar with combustion, purging, flame sensing etc. Just no experience with small domestic systems. If I let the boiler go to lock-out it will restart after a short period - say 2 minutes.

What does that solenoid do? It doesn't feel warm to the touch when running or after lock-out.

George G
August 2009

Initially George I would think that the solenoid on top of the oil pump could be failing here - if the boiler gets going again once it has cooled off. Mind you, it could just be that the whole boiler needs a good clean out - from firebox, through the baffles to the flue. A good indicator of needing a clean is a chuffing sound when the burner is going, and black smoke at the flue.

John
August 2009