Heatslave 12/18 lockout when cold

[R3su]

Hi all,

My boiler has recently undergone some work (new pump, filter, tigerloop etc) and thankfully it’s up and running again for the most part. Unfortunately we now have an ongoing issue of the boiler going to lockout when it tries to fire from cold.
I’ll then have to reset it twice to get it to fire and it’ll run happily until the end of the heating cycle.
It’s a Bentone burner and has recently had a new nozzle.

has anyone got any thoughts?

many thanks

 

[muggles]

Quite possibly the capacitor but without more information it's hard to be sure. Does it sound like the motor is spinning or not?

 

[Burnerman]

The pump is held in by three allen screws......just slacken them a little - don't remove them of course.
John

 

[oilhead]

If the motor just buzzes on the startup, then the capacitor is suspect. If however the motor spins, then check all your oil connections to ensure that there are no leaks causing oil to run back during the off periods. Have a look at the tiger loop while it is running to see if there is any aeration. Finally, was the combustion checked with an analyser to set the combustion. If it is too lean a mixture then that will cause your symptoms.

 

[R3su]

Hi all

thank you for the responses so far.
Unfortunately work pressures have meant I haven’t been able to give the boiler a proper look since posting.
I have managed to make a video of it attempting to fire.

 

[oilhead]

This sounds as though it is lighting but locking out after the post ignition safety time which suggests a faulty photocell or control box.

 

[Terrywookfit]

Or excess air (As you previously mentioned). Especially if a smaller nozzle was fitted without checking O /P ..CO2.

 

[R3su]

Thank you for the responses. Photocell was replaced recently as the previous one ate itself.
With regards to control box is that the clear burner control box?

I’ll check if the engineer tested with an analyser. I know after his first visit it really smelt wrong. Now it’s smelling fairly sweet, not quite like it was but a lot closer.

is it still worth checking the motor housing screws or is the fact that it runs on second fire ok?

the tiger loop just fills slightly with oil (there already oil in it but the level increases l) and that’s it, no bubbles or anything.

 

[Burnerman]

The boiler is obviously igniting and then locking out straight away.....if the motor spins every time then ignore my idea concerning the motor mounting screws.
This is pretty typical of a photocell problem, as the other guys have suggested.
This is only my opinion but I have found on more than one occasion a dud photocell has goosed the control box too.....is it a Satronic 830 by any chance?
John

 

[R3su]

Hi John
It’s a bentone dko 970 21 which give me google search results as satronics and Honeywells.

do you know if there’s a way to test the control box or is it a case of replace it and see?

with regards to the photocell I wonder if it beltching black smoke before the repair has messed up the cell.

 

[oilhead]

If the photocell has not been cleaned since the black smoke episode, then that may all that is required.
https://www.satronic.co.uk/download/dko970-972.pdf gives you the fault code diagnosis.

 

[R3su]

Checked the control unit and it was giving the fault code short flash and four long which gives the cause as “within lockout safety time. No flame establishment”.


Ive checked the photo sensor and given it a wipe over but it was spotless.

 

[oilhead]

When starting, lightly cover the air intake with your hand and see if that enables a continuous burn. If it does then it seems like an overaired problem.