Problem getting burner to keep firing

[Best]

Since he ruled out the solenoid and cell, then has to be control box doing a steady second fail.
But you can get new solenoids failing.
I would have swapped the box for a new one to test it instantly.

 

[Robert Tyrrell]

I have swapped out the control box with a new one but it was an older model.
The pump is an 11L3, if memory serves me right. Do they come set up for two pipe now as well?

 

[Best]

I have swapped out the control box with a new one but it was an older model.
The pump is an 11L3, if memory serves me right. Do they come set up for two pipe now as well?

I am not sure, but as it is a wee washer in the 11L3 for one pipe, I would assume it will remain done that way and washer only needs removed for any that are 2 pipe

 

[Gazzt]

I think the danfoss 21r and 21l are set for two pipe, bfp11 come 1 pipe, but check documentation.
After changing all the parts are you still getting lock out.

 

[Gazzt]

I know this might sound daft but is there enough oil in the tank, and if you use a vacuum gauge on the pump it will let you know if you have a blockage, i has seen remote fire valves block with sludge and also they can fail and stick in the closed position.

 

[Robert Tyrrell]

I know this might sound daft but is there enough oil in the tank, and if you use a vacuum gauge on the pump it will let you know if you have a blockage, i has seen remote fire valves block with sludge and also they can fail and stick in the closed position.

Definitely enough oil in the tank and yes, it still went to lockout. There's no blockage at the fire valve either so unless there's any other suggestions I'm going to look at the heating pump, although I don't see how a faulty heating pump would stop the burner working on the hot water side.

 

[Gazzt]

Heating pump failure would affect the high limit on the stat. Are the electrodes correct and aren't cracked, also check the transformer. If the burner locks out after 9 sec the control box is not satisfied a good flame is established. Usally the electrodes should buzz for 12 secs or longer to ensure good ignition and to satisfy the photocell the flame is established. What type of burner is on it.

 

[Best]

Burner going to lockout means fault is at burner only, or oil problem.
Just check if flame is established and is reasonable before burner locks out.
I don't want to go into more detail on open forum about how I test burners

 

[Robert Tyrrell]

Heating pump failure would affect the high limit on the stat. Are the electrodes correct and aren't cracked, also check the transformer. If the burner locks out after 9 sec the control box is not satisfied a good flame is established. Usally the electrodes should buzz for 12 secs or longer to ensure good ignition and to satisfy the photocell the flame is established. What type of burner is on it.

The burner is a sterling 50 as per the MI. I've set it up as per the MI as well

 

[Robert Tyrrell]

Burner going to lockout means fault is at burner only, or oil problem.
Just check if flame is established and is reasonable before burner locks out.
I don't want to go into more detail on open forum about how I test burners

I agree with your assessment that it's at the burner but as it's clearly causing me a problem I'm open to all suggestions as food for thought while I'm lying on my sunbed by the pool
I did check that there was a good flame at the burner so it might be the transformer, or the leads, but surely that would cause an intermittent fault with the initial firing as well. It fires every time, after the reset but still goes to lockout