Honeywell / Satronic control box DKO 970 for Wallstar 15/20

[MM]

This is the oil burner safety control (model DKO 970) on my Wallstar

15/20 boiler, which once again is playing up.

I downloaded the 6-page manual

for the DKO 970 and studied the flash codes.

In the manual on page 2 in the paragraph "1.2 Lock-out diagnoses" it says the following:

In case of a failure the LED is permanently illuminated. Every

10 seconds the illumination is interrupted by a flash code, which indicates the cause of the error. Therefore the following sequence is performed which is repeated as long as the unit is not reset.

Sequence:

illuminated phase dark phase Flash-Code dark phase x z z z z

[where illuminated phase = 10 sec, dark phase = 0.6 sec, second dark phase = 1.2 sec -- I can't fit all that on one line in FreeAgent like in the actual PDF]

Error diagnosis Error message: lockout Flash-Code: x z z z z Possible fault: within lock out safety time no flame establishment

[where x = short pulse, z = long pulse]

This is the sequence I observe on my boiler when it won't start.

So my question is:

What does "within lock out safety time no flame establishment" mean in layman's language?

Does this point to the burner, the igniter, the solenoid, or another component?

NB: The boiler ALWAYS starts when I press the reset button on the DKO

970. I never have to press it more than once. The boiler then runs perfectly, cycling through on/off phases exactly as it should.

But next morning it won't start and the above flash code sequence can be observed. There's plenty of oil in the tank.

Thanks.

MM

[Allan Mac]

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0x z z z z

If the photocell doesn't see a flame within a preset period the ignition process stops. This prevents oil being squirted into the burner, and a potential explotion. There are a few possible causes

Dirty photocell No ignition spark Oil valve not opening Faulty control box clogged nozzle Faulty oil pump

Diagnosis of this kind of fault can be difficult.

Good luck. Allan

[Allan Mac]

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0x z z z z

Just remembered, saw this once before where the plastic drive coupling to the oil pump had worn

[MM]

Thanks for that useful advice, Allan. I'll pass it on to my heating engineer. He's a bit flummoxed over my boiler, but has a good reputation. On Wednesday he fitted a new transformer.

Unlikely to be the pump, as he fitted a new one two years ago. When I told him the reset switch was still having to be pressed, he asked me to note down the control's model number, so I assume he's sourcing a new one or maybe himself researching the flash codes (which I had told him).

Not a problem all the while I'm here, but when I go away and there's a sudden cold snap, that's when the boiler needs to be utterly reliable otherwise the house goes cold and there's then the risk of frozen pipes.

My gas boiler down in High Wycombe seemed simple in comparison with this Wallstar! It was maintained each year by Servowarm, who only needed to fit a new thermocouple every few years. That gas boiler was

23 years old by the time I moved out.

You're telling me! Heating engineer said he had one stubborn case (different make of oil boiler though) that he was working on for several days.

Cheers!

MM

[ARW]

Have you considered using an engineer that knows what they are doing?

[MM]

No, of course not! Are you mad, sir?

MM