Have you found the problem with this. I am having exactly the same issue with my boiler which is also a danesmoor 12/14. Firstly my boiler stopped working. After much searching I found the supply line from pump to nozzle was chocked. I also noticed a cracked electrode so I’ve fitted new electrodes, new nozzle and cleared the supply line from pump to nozzle. My boiler now starts up you hear the flame igniting for about 4-5 seconds then it locks out. I’m about ready to Chuck the thing away but know it must be something simple.
Worcester Heatslave 12/14 going into lockout
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Have you done the checks already outlined in the thread? Does the burner light then lockout, or does it just purge?
Follow the fault finding chart not assuming something is ok. If it is not lighting, are you getting a spark?
Follow the fault finding chart not assuming something is ok. If it is not lighting, are you getting a spark?
Yes have done all the tests. Checked for spark prior to fitting blast tube and after. Solenoid checked all ok.
It certainly sounds like it’s firing up. If I remove the burner as soon as it’s locked out the blast tube is damp with fuel and slightly warm.
Just checked resistance on photocell and that’s working.
Got a guy coming tonight to check the pump pressure.
It certainly sounds like it’s firing up. If I remove the burner as soon as it’s locked out the blast tube is damp with fuel and slightly warm.
Just checked resistance on photocell and that’s working.
Got a guy coming tonight to check the pump pressure.
So adjusted the pressure up from 80 to 100 psi. Still no better. Boiler fires up then cuts out after 4-5 seconds. All roads seem to point to the photocell or control box.
We tried a test tonight. Took the photocell out and shone a light at it and fired up the boiler. It did exactly the same. Fired up for 4-5 seconds then locked out. Correct me if I’m wrong but if the photocell sees light on start up it shout not produce spark as it deems the burner to be already lit. Is that correct?
The next scenario is that when checking the resistance of the photocell it shows open circuit when dark then shows resistance when in light. So looks like it might be working. Anyone know what resistance figures I should be getting?
We tried a test tonight. Took the photocell out and shone a light at it and fired up the boiler. It did exactly the same. Fired up for 4-5 seconds then locked out. Correct me if I’m wrong but if the photocell sees light on start up it shout not produce spark as it deems the burner to be already lit. Is that correct?
The next scenario is that when checking the resistance of the photocell it shows open circuit when dark then shows resistance when in light. So looks like it might be working. Anyone know what resistance figures I should be getting?
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Your photocell, in complete darkness should have a very high resistance - somewhere in the 20 megohm area and when introduced to light this should fall to around the 10k ohm region.
Obviously these figures aren't anything other than typical as light levels vary - as do photocells themselves.
On start up, the burner should purge fresh air only for around 8 sec (the spark will be present here) and then the fuel is electrically switched on courtesy of the solenoid on the top of the oil pump. If the photocell sees no light the burner should ignite to flame. Once the photocell sees bright light the spark is extinguished and the burner should continue to run.
The burner won't start if the photocell sees light initially.
If I'm bench testing the burner - I have to sometimes as you cant always adjust the oil pressure when its in its housing - I hold the photocell in my closed hand, switch the burner on and immediately it starts burning I open my hand to let the photocell see the flame.
One more thing - if you have adjusted the oil pump pressure you really need to have an analysis of the flue gases,looking for approximately 11% CO2. 100 psi sounds about right for this boiler.
John
Obviously these figures aren't anything other than typical as light levels vary - as do photocells themselves.
On start up, the burner should purge fresh air only for around 8 sec (the spark will be present here) and then the fuel is electrically switched on courtesy of the solenoid on the top of the oil pump. If the photocell sees no light the burner should ignite to flame. Once the photocell sees bright light the spark is extinguished and the burner should continue to run.
The burner won't start if the photocell sees light initially.
If I'm bench testing the burner - I have to sometimes as you cant always adjust the oil pressure when its in its housing - I hold the photocell in my closed hand, switch the burner on and immediately it starts burning I open my hand to let the photocell see the flame.
One more thing - if you have adjusted the oil pump pressure you really need to have an analysis of the flue gases,looking for approximately 11% CO2. 100 psi sounds about right for this boiler.
John
A competent service engineer would probably have in his spares, a photocell and a control box. In your position as a DIYer, I would first buy a photocell, and if the fault persists then replace the control box. As a professional, I may well find another source of your problem, but taking at face value your actions, it suggests a fault in flame sensing, which is the photocell or control box.
I’ve ordered up photocell and control box due to arrive today. Service engineer coming to fit and test so hopefully I’ll have heat tonight.
Hi Guys,
I have been meaning to write up the steps I went through for quite a while, time seems to have eluded me!
I have run through all the tests suggested by the helpful forum members in this thread, checking and then replacing the photocell, setting up the electrodes etc. all with no difference in symptoms.
I had tried to find a new control box and have been told by several wholesalers that they are no longer available and a newer compatible version was also not available, meaning that I had to replace the burner or the boiler. Faced with the decreasing range of options, I decided I had nothing to lose and took the control box apart.
Inside is a strange arrangement of multiple relay contacts, some resistors and diodes and a large relay coil. Shining a torch into the electronics, I managed to identify a broken wire on the base of the relay coil, this was quickly re-soldered onto the printed circuit board. The re-installed control box didn't work straight away, I also found some dry solder joints on the control box PCB and the terminal PCB in the control box base, so it's worth checking there as well.
Once I was sure everything inside the control box was connected to where it should be, it was re-installed and then the boiler fired up and remained running, as it still does today (touch wood). There were a number of random lock-outs in the first week, but these have cleared up.
About two weeks after the boiler was working, it went into lockout again, this time it turned out to be the solenoid valve electrical coil burnt out, open circuit when checked with a multimeter. It turned out I had put the spring washer on the spigot before the coil and then the lock nut, whereas it should be coil, spring washer then lock nut. The coil has been replaced and the boiler is now working fine.
I have also found out from the manufacturer that a new version control box is available, so I have a cheaper option than replacing the burner or boiler should it stop working again, hopefully not.
Hope this helps.
Tony
I have been meaning to write up the steps I went through for quite a while, time seems to have eluded me!
I have run through all the tests suggested by the helpful forum members in this thread, checking and then replacing the photocell, setting up the electrodes etc. all with no difference in symptoms.
I had tried to find a new control box and have been told by several wholesalers that they are no longer available and a newer compatible version was also not available, meaning that I had to replace the burner or the boiler. Faced with the decreasing range of options, I decided I had nothing to lose and took the control box apart.
Inside is a strange arrangement of multiple relay contacts, some resistors and diodes and a large relay coil. Shining a torch into the electronics, I managed to identify a broken wire on the base of the relay coil, this was quickly re-soldered onto the printed circuit board. The re-installed control box didn't work straight away, I also found some dry solder joints on the control box PCB and the terminal PCB in the control box base, so it's worth checking there as well.
Once I was sure everything inside the control box was connected to where it should be, it was re-installed and then the boiler fired up and remained running, as it still does today (touch wood). There were a number of random lock-outs in the first week, but these have cleared up.
About two weeks after the boiler was working, it went into lockout again, this time it turned out to be the solenoid valve electrical coil burnt out, open circuit when checked with a multimeter. It turned out I had put the spring washer on the spigot before the coil and then the lock nut, whereas it should be coil, spring washer then lock nut. The coil has been replaced and the boiler is now working fine.
I have also found out from the manufacturer that a new version control box is available, so I have a cheaper option than replacing the burner or boiler should it stop working again, hopefully not.
Hope this helps.
Tony
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sounds like you got air in oil there is a blead point on burner but i won't do it yourself,good chance your going to get wet.
That’s my burner back up and running. Turns out it was the control box. I got a new upgraded control box off the shelf from plumb centre. (Danfoss 057H8102)
Cheers for all the help lads.
Cheers for all the help lads.
Can't help but feel a competent service engineer would have solved this in one visit, maybe two depending on spares carried. Danfoss solenoid coils fail randomly, to the point where a regular service engineer may change them arbitrarily after 3 or 4 years. The latest Danfoss advice is they are good for 10,000 operations. This can be a relatively short time on a combi. Oil burners are basically a simple piece of kit, and if the simple things are done in an orderly fashion, problems are solved.
Yup fully agree follow the fault finding list can't go wrong.Bob
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