Oil pump fault on boiler?

19 Feb 2003
Reaction score
United Kingdom
Hi, I noticed my heating wasnt working this morning. After quick investigation i found that the water pump on the boiler was working fine but the oil pump runs for about 10 secs then cuts out and you have to press the reset button to restart.
I striped the system down to see if the jet was blocked but it seems to be working fine apart from no oil getting to the jet.
I traced the fault back to the oil pump, the pump seems to be running, oil is going into the pump but none is coming out.
I took this picture of the pump to try and explain better.


Oil flows fine in from the pipe at the bottom but none comes out from the L shaped pipe at the top right. Loosening the L shaped pipe slightly lets oil leak out so the blockage seems to be inside that pipe.

Does anyone have any suggestions what is wrong? Also does anyone know what the we electronic part is just under the red plate, looks to be a heater of some sort???


Edit:= Picture doesnt seem to work please click on link.
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you have an old pump, it could be the msla coil, which is under the red plate & wired to control box.
Do you know what the msla coil does? ie is it a heater or a solenoid.

If it is not functioning would that stop the oil getting through the pump? Or is my problem more likely to be with a blockage in that silver L shape pipe?

after a set period of time, (usually seconds) the coil lifts a soleniod which then allows 100/120psi (approx, if its 28 sec) to get to nozzle. the control box controls it, but msla coils are prone to failure. but to be honest it can be many other things. i would get someone in to look @ it.
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As wilhelm says, it is likely to be the coil. It is very unlikely to be a blockage. It could be other things, but blockage isn't the most likely.
Thanks guys,

I checked that solenoid earlier tonite by removing it and placing a screwdriver inside it and turning the boiler on. The magnetic field was barely noticable inside the hole.

I presume that if working properly the solenoid should be strong enough to hold a small screwdriver reasonably firmly.

It the MSlA coil is weak, then the control box should be ok.

If i was you i would replace the oil pump (danfoss LEFT HAND PUMP)because with a new pump you also get a coil supplied. A msla coil is about £25.00 +vat, You should be fit to pick up a danfoss pump for £30.00 +vat.

P.s If you go for the pump remember to get a coil lead.
That's unfair. If Zordey replaces the coil, that's it, job done. Replacing the pump means ensuring the joints are oil tight, and that no problems have been generated, AND having to check the pump pressure AND setting the air for correct combustion. Not to mention you're working clean enough to prevent debris getting into the pump.
Thanks again for the help. I just went and got the coil and 10 minutes fitting later the boiler is working again. Infact it almost seems to be working better than it did before if that is possible, altho that may just be because its been a couple of days since iv had any heat. :)

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