Riello burner lockout.

[greenfingersjim]

this is what happens. Any ideas most likely cause. Burner locks out. I press the reset and can hear the fan is not spinning. I remove the burner and fan cover to check motor isn’t seized. It’s not and I spin the fan by hand put back together press reset and it fires and heats up correctly. When temperature is reached it switches off correctly but then is locked out when call for heat later and I have to repeat above. I assume a motor issue, but why does turning the fan/motor a little make a difference. Thanks

 

[DetlefSchmitz]

New capacitor?

 

[greenfingersjim]

Also could a fuel pump issue stop the motor/ fan from spinning on start up. I assume it would it still spin regardless of pump issues.

 

[greenfingersjim]

I thought I’d start with the capacitor, but not sure manually rotating the fan would work like this if the capacitor is faulty.

 

[DetlefSchmitz]

The reason I'd start with the capacitor is purely down to cost. Pumps are more expensive. If you have a decent multimeter you could measure the capacitor value, for free.

If you could spin the fan by hand then it seems unlikely that the pump could be stopping it.

However I am not a boiler engineer. I just have a boiler with a Riello burner.

 

[Johntheo5]

this is what happens. Any ideas most likely cause. Burner locks out. I press the reset and can hear the fan is not spinning. I remove the burner and fan cover to check motor isn’t seized. It’s not and I spin the fan by hand put back together press reset and it fires and heats up correctly. When temperature is reached it switches off correctly but then is locked out when call for heat later and I have to repeat above. I assume a motor issue, but why does turning the fan/motor a little make a difference. Thanks

Are you sure the fan cover isn't fouling the fan?
Normally, if this happens though you will hear a buzzing, as suggested also possibly a weak capacitor and cheap to renew

 

[greenfingersjim]

My multimeter doesn’t have a capacitance function, but am I right in thinking the capacitor should be charged and register voltage when the boiler is idle?

 

[Johntheo5]

Yes, thats correct but I don't think you can measutre voltage across them.

 

[greenfingersjim]

Thanks. No voltage at all. When running it records 240v or so, but nothing when I check after it switches off. I’ll try a new one. I did wonder about the fan, but there’s plenty of clearance around it and no noise when it is spinning.

 

[Johntheo5]

You are probably better off getting a Riello approved one as they have a stud I think to screw them neatly onto the burner body.

 

[greenfingersjim]

Yes it does. I’ll check at local plumbers merchant tomorrow, but probably next week before I get it. I’ll update the thread then.

 

[oilhead]

If you can only get the right value as one without the stud, then just attach it to the existing capacitor with cable ties until you can get the correct one