Danesmoor Oil Boiler - starts, runs, stops!

[beveldrive]

Hi, I have a Danesmoor 15/19. It's been running ok than packed up about a month ago. It was obvious that it hadn't been serviced for years. The oil pump was stiff to turn and filters were semi blocked. So I fitted new oil pump and replaced a few other parts and reset the ignition probes, cleaned the baffle plates etc.
This morning fired it up. It ran for about 15 mins. The flue got nice and the water pipes warmed up nicely....then it stopped and I can't restart it.

Any ideas, please?

Steve

 

[Fat Bob]

When you now press the reset button on the control box, what exactly happens? Do you hear the fan running? Do you hear it trying to ignite?

If the filters were badly blocked up. I would check your oil tank for water. You can buy a paste you put on a poll, stick etc and it changes colour in the presence of water.

 

[beveldrive]

Hi Bob, thanks for quick response. Come to think of it, I didn't see any indicator lights on the control box at any time when it ran or now after it stopped.

 

[Fat Bob]

Hi Bob, thanks for quick response. Come to think of it, I didn't see any indicator lights on the control box at any time when it ran or now after it stopped.

If you are pressing the button on the control box, and nothing is happening at all, it sounds like the boiler is up to temperature, and the pump is not circulating the water around the system.

When the boiler was running for 15 minutes, did the radiators start to heat up, or was it just the pipes at the boiler that were very hot?

If the pipes at the boiler were just very hot, and the radiators were not heating up then it is the circulating pump that is faulty.

If the radiators were heating up, and nothing happens when you press the control box button, then it looks like the overheat thermostat has cut the boiler off. What do do is look for a black nipple on the front face of the boiler next to the boiler thermostat, it should unscrew and reveal a white button press that and the boiler should start working again, then all you need to do is turn the boiler thermostat down half of what it is right now, an the boiler will not trip the overheat switch again.

 

[beveldrive]

Well I've just rotated the temp control on the front panel of the boiler to the next heat setting and it fired up again, ran for 4 mins and cut out. Flue is hot and out going water pipe is hot. I'm going to check the circulating pump as you suggest.

 

[Fat Bob]

Well I've just rotated the temp control on the front panel of the boiler to the next heat setting and it fired up again, ran for 4 mins and cut out. Flue is hot and out going water pipe is hot. I'm going to check the circulating pump as you suggest.

Yes that sounds like what it is.

 

[beveldrive]

Well I checked the circulating pump and it's spinning freely so not sure what to check now.
I can't find any overheat cut-outs or reset buttons anywhere. I've set the programmer to hotwater and heating but as the boiler only runs for 4 mins (always the same time, never varies!) the rads barely get warm and the same goes for the hot water. It does seem like the boiler core is heating during that 4 minute burn and then tripping out. What to do?

 

[Fat Bob]

It's definitely a circulation problem. Just because the pump rotates does not mean the pump is fully healthy.

Tell me more about the system, by answering these questions.

Do you have a pressurised system you need to top up, or system fed from a header tank in the attack?

Do you have a three port valve, or two two port valves?

What work, if any have you done to the system since it was last working ok?

 

[beveldrive]

It's fed from a tank in roof.
3 port valve
All I've done is replace a few components in the burner, as mentioned above. Only did that because the boiler stopped working ...no record of any servicing on the boiler from previous owner.

 

[Fat Bob]

It's fed from a tank in roof.
3 port valve
All I've done is replace a few components in the burner, as mentioned above. Only did that because the boiler stopped working ...no record of any servicing on the boiler from previous owner.

Have you just moved in, or has the boiler been working ok previous to this?

If you moved in a while ago, and have not been having any problems up until now, I would replace the pump.

A few checks to do beforehand trying turning the pump speed to maximum and see if it makes any difference. Check all valves are fully open, and try bleeding air out of boiler, radiators and any bleed points. If it still does not work you need to replace the pump.

 

[beveldrive]

I moved in 18 months ago. The boiler worked ok for a few months but then refused to start. I replaced oil pump (BFP 41 L3) pump solenoid and motor capacitor.
Ok, will tyr that , thanks.

 

[beveldrive]

Bob, thanks!
Set the pump speed to max and did complete bleed. All is now toastie and boiler is firing regularly and for as long as is necessary.
Still gonna replace the circ pump though, just to be on the safe side!

Cheers mate!

 

[Fat Bob]

Bob, thanks!
Set the pump speed to max and did complete bleed. All is now toastie and boiler is firing regularly and for as long as is necessary.
Still gonna replace the circ pump though, just to be on the safe side!

Cheers mate!

Thanks for letting me know everything went well. Glad I could help.