Riello 40 oil burner ignition problem

[millemg]

I have been having problems with intermittent ignition issues with this burner. It runs but no ignition. I have done some maintenance, cleaned out the boiler chamber and plates, fan and casing cleaned, burner tube cleaned, nozzle filter cleaned, all is running ok, apart from ignition. I read about the photocell being an issue, so yesterday I received a new one in the post, fitted it, and it fired up perfectly and ran all afternoon and evening switching on and off with the thermostat etc. This morning I have tried to start it up, and it is back to square one, running but no ignition. If I remove the photocell, it fires up after 12 seconds, then goes to lockout.

Any advice would be great, thank you

 

[oilhead]

Check the white wire off the motor for 50 volts, you may have a problem there. Also clean up the contacts for the P/cell on the control box and make sure the spring contacts are tight. You could also check the operation of the P/cell with a multimeter, that may be faulty even though it's new.

 

[millemg]

Thanks for your reply. I have got another photocell on it's way, so I'll try that. How do I go about measuring the 50v supply from the motor please? If this reading is not 50v, would the motor still run as normal, as it was working ok before the photocell problem ?

 

[oilhead]

You need a multimeter to check voltage. The motor will still run as this is 240 volt, but the 50v feeds the control circuit so could cause your problem.
As the burner now runs, fires and then goes to lockout the fault would appear to be either the p/cell or the control box.

 

[millemg]

Thanks again, I do have a meter, just not sure if the motor needs to be running etc to take measurement ? The photocell will be here in the next day or so, but I can still measure the 50v if I know how to do it.

 

[oilhead]

With motor running using the points at the front of the control boxbase.

 

[Terrywookfit]

Measure voltage across white and black wires with motor running.
The resistance reading is around 10Ω. NOT WITH POWER ON !!

 

[millemg]

I've measured the motor output voltage today, exactly 50v, so it still points to photocell or control box. I'm still waiting for the cell to arrive. I will reply as soon as I know more. Thanks

 

[BoilerBob]

Could be the cell has got dirty give it a rub then try it. Bob

 

[millemg]

No, it's not that, I've cleaned the old one, then replaced it with a new one, which I suspect is also faulty.

 

[Terrywookfit]

You may need a 530SE to go with it.

 

[oilhead]

If it still lights but goes to lockout without a p/cell fitted, then the control box should be OK. Keep your fingers crossed with the new cell.

 

[millemg]

RESULT ...... fitted the new photocell and it's working great again !!!

One thing to think about. I'm not saying I did this on the previous photocell, I can't remember, but something to think about before testing sensitive components.

"Regarding the risks of introducing a voltage through the multimeter leads :

• Yes, there is a risk of certain parts being damaged, especially parts that can not tolerate the 1 to 9 volts that a multimeter might deliver across the probes in continuity mode. "

(I have just used another meter to read my probes on continuity setting, and it is pushing out 2.5v to perform the test)

Thanks for your help, now I will be having fun trying to bleed and balance the system after draining and replacing a rad !!!!