Old oil (paraffin/kerosine) fired boiler problem

Hi, I would be grateful for help with a diagnosis. The boiler stopped working and the red reset was lit. When I press it, the fan starts up and I think I can hear the ignition spark behind the noise of the fan. After a few seconds, I can see an electric. blue star through the dark window you can see on the photo. Below that, I can see some yellow flame. So, it looks like the oil is igniting but only for a few seconds. After that, it seems to give a gentle cough and cuts out and the red reset light is back on. If I press it again it starts up for an even shorter time and then it needs a good long rest before it will try to start up again.

Any suggestions gratefully received. My old dad used to fix this boiler when it broke down and I wish I had paid more attention to what he was doing. Good old dad. Anyway, could it be the electric eye needs cleaned or replaced? I don't even know where to look for it so any help would be most welcome.

There is a sequence of checks for fault diagnosis. First, prove your oil supply to the burner, check that you have oil, and that any tank filters or external filters are clean and pipework is clear. There are two bleed screws on the red filter that will allow this check. Once oil supply is confirmed, move to the oil pump. You need to check it is actually supplying oil to the nozzle. From your photos, it looks like at some stage, the fuel pump has been changed to one that incorporates a solenoid valve, with the original still in place but presumably 'filleted'. In the absence of a pressure gauge, disconnect the oil supply to the nozzle feed, have a container such a jar or bottle into which you can insert the pipe and try to start the burner. The oil should squirt through this at quite a pace (125 psi ish). If it doesn't, the fault is within the pump or solenoid valve, or the drive coupling from the motor to the pump. With a small flame, this seems to be the starting point. You may also have a blocked nozzle which can give this symptom.

Hi, thanks for the informed advice, I'll investigate tomorrow. I already tried to get an engineer to service the boiler but they took one look at it and said that it needed replaced along with the flue. However, I am pretty competent on the car mechanics and domestic electrics so I am more than willing to tackle the boiler myself.

I would be grateful for further advice on this Danesmoor DF 20/30 boiler. The baffles are corroded and partially collapsed. I scoured the internet and I can't even find a copy of a manual or any spare parts. Can you suggest a source for old baffles? Also, someone suggest that I take the old ones to a sheet metal shop and have them reproduced. What is your view on this idea. Am I likely to succeed.

Many thanks in advance.

I don’t think you’ll ever source baffles for this boiler.....I’m in a similar situation with my ancient Panda.
Anyway, making the baffles is dead easy for anyone with a MIG welder, an angle grinder and some 3mm mild steel sheet.
My baffles were more burnt than corroded which told me the burner was overfiring with excess oil pressure which I’ve since corrected.
At a guess I’d say the photocell (magic eye) is sorted up.....I don’t know where it is but it’s in a place where it can see the flame and usually plug in the side of the burner.
You may find parts like electrodes etc from www.heating-parts.co.uk
John

Hi John, OK, 3mm sheet steel it is then. The baffles were probably burned as well as corroded. I'll probably make it a project and bring this system back up to near to full working order. Did you need a pressure gauge to adjust the pressure?

Another issue is that we used to have control over the temperature of the hot water via the on/of rotating knob on the front of the boiler. Now it is just off or very hot. The switch is connected to one of those sensors what work on back pressure through a very thin copper tube. I'm guessing that replacing that is a lost cause unless someone here has done it and recons its easier than it looks at first sight.

Best, Ronnie.

For sure, if you want to bash on an oil pressure gauge is needed to set the oil pressure.....they usually screw into the side of the oil pump via a port marked P.
I’ve no idea what pressure is recommended - I’ll guess at 110 psi but maybe others will know.
You’ll also need a flue gas analyser to measure the CO2 output - again I’ll guess at 11%. These analysers are very expensive but the oil gauge is around £20.
With my own burner I blast it through with compressed air to shift any soot and dust.
Typically, the electrodes are around 2mm behind the nozzle (the air blast blows the spark into the kero spray) and the gap between them 3mm.
As I can’t adjust my burner pressure in situ, I’ve rigged up a gravity kero tank and electrical supply where I can fire the thing up on the bench.
It also sounds like you have a thermostat which has gone awol.....these typically push into a steel pocket on the upper side of the boiler. You may be able to match one from the firm I’ve mentioned.
Good luck with it! I managed to find a replacement burner on ebay for mine.....typically mounting brackets for burners are standardised, but the blast tube that pokes into the boiler firebox need to be the same length as the original.
I guess it all depends how much you like tinkering! I’d hate you to chuck money down the drain - maybe a new burner (or even boiler!) could be the way but in my opinion if the boiler isn’t leaking - it stays.
John

I’d say you’re spot on John with all you’ve said if he gets the nozzle out he’ll find the size prob 0.65 let’s guess and say W so 110 will be the right pressure
I make baffles all the time and have had no probs and,if it ain’t leaking I’m with you keep it. Bob

Many thanks for your input, Bob!
I must confess I’ve never seen this burner never mind fiddled with one.
John

D42 aren't as strtaightforward as modern burners when it comes to adjusting the air or nozzle position if it has been moved. Balancing up CO2 and CO can be a fiddle. It should run somewhere 110 -125 psi. with a CO2 around 11%. I would think in the day, most of these were set up by eye and smoke pump and thermometer. With an old Satronic TF701, there is a good chance that may have failed, but if it were just down to a photocell, I would have expected it to run for a few seconds before cutting out, not just a small puff. That sounds more like fuel problems with a blocked filter, failed pump or worn out drive dog.

Regarding Baffles...
Some of the older Danesmore boilers had folded sheet steel that formed a box around the heat ex held in position by lugs and a spring loaded lid in the middle.

Hi Terrywookfit,
Thanks for the comment. I don't like the sound of a spring loaded lid in the middle. I took a photo and wondered if you can tell which type I have.
Thanks, Ronnie.

You have the plate steel baffles so no problem.

If you need the manual.
https://www.nu-way.co.uk/wp-content/uploads/2019/10/D42-Manual.pdf

Dimensions for the blast tube etc are in there as well. Friend with lathe would sort.