URGENT Firebird Riello Motor Hot

[AlanLJ]

Hello all.

I'm looking for advice to help my heating engineer fix my problem! He actually installed the unit.
It’s a 3 year old oil boiler, a Firebird with C26 Riello burner.
It’s been running fine since installation, but went into Lockout a couple of weeks ago.
The engineer first changed the kerosene pump saying it was very stiff to turn, which seemed true actually. He also changed the nozzle. This made no difference to the problem though … still kept locking out after a few minutes.

He noticed that the motor which drives the kerosene pump was getting hot to touch after 5 minutes of use, so then changed that too. However, again this made no difference to the problem … still kept locking out after a few minutes … and the new motor also gets very hot to touch. New capacitor came with the new motor.

Frustrated, after a few days on non-use, and a very annoyed wife, I fired the boiler up myself. I noticed quite a lot of blue smoke coming from the vent, whereas previously it had always been clear, with only a hint of light colour detectable on cold days.

The engineer returned for a 3rd visit, and dealt with the blue smoke by adjusting the ‘air damper adjustment screw’ … I’m looking through the Riello manual as I type! Lol. He plugged a monitor in whilst doing this. During this 3rd visit, I know he pulled the whole Riello unit out and took much of it apart. He’s gone again now saying that he’ll have to speak with Riello. That’s fair enough.

My own little bit of diagnosis:
The boiler will fire up and continue running until something tells it to stop!
It’ll happily heat up the domestic hot water as well as the house radiators, but as soon as you start/stop a hot water tap, or it receives a signal from the Honeywell Wi-Fi thermostat (saying the house reached the desire temp), it goes into lockout.

At this point, the kerosene motor will be very hot, and you won’t be able to reset the lockout for several minutes. I’m presuming a safety temp control thermostat is causing that?

My question is: could the motor be spinning too fast, hence the reason for becoming very hot?
Could this be driving too much kerosene into the burner, hence that blue smoke?
Could it be that the new capacitor is faulty?
Or perhaps something’s simply gone wrong in the Control Box?

If anyone has any ideas on this one, it would be very much appreciated!

Cheers, guys.

 

[SJB060685]

A motor burns hot if the capacitor is weak or too strong, the motor windings could be failing, or a stiff pump, bearings or fan.
Do you have a multimeter capable of measuring capacitance?

 

[AlanLJ]

A motor burns hot if the capacitor is weak or too strong, the motor windings could be failing, or a stiff pump, bearings or fan.
Do you have a multimeter capable of measuring capacitance?

Hi SJB060685.
I can only presume (and hope) that the engineer did check the capacitor. I think he replaced both the kerosene pump and the motor for a second time.
He's very experienced and professional, hence this little problem has quite upset him . . . as well as my wife who can't dry the washing on the radiators! Lol.
As you say, it might be the fan that's failing too. Just seems odd that the boiler will run until interrupted, at which point it locks out, and needs to cool down
before accepting a reset.
Very many thanks for your help.
Cheers.
Alan.

 

[SJB060685]

The burner control box has no way of telling if the motor is running too hot. There is no temperature sensor that would cause a control box lockout. Any chance of a video showing the burner going through its relight cycle?

 

[AlanLJ]

The burner control box has no way of telling if the motor is running too hot. There is no temperature sensor that would cause a control box lockout. Any chance of a video showing the burner going through its relight cycle?

Thanks again, SBJ060685.
I'll try to do that asap. Just to say, there are no unusual noises, and the start-up cycle sounds quiet and normal ... to the uninitiated such as me!

 

[SJB060685]

With the boiler running try and initiate an interuption by turning the boiler stat down, the burner will shut down, then turn the dial up and be recording the burner so I can see and hear what the burner is trying to do please.

 

[AlanLJ]

Thanks again, SBJ060685.
I'll try to do that asap. Just to say, there are no unusual noises, and the start-up cycle sounds quiet and normal *** to the uninitiated such as me!

I've fired up the boiler this evening, and made a few videos of each startup; that being, it did of course go into lockout a few times, and
therefore require a reset several times.
The motor is hot, certainly, but perhaps not unbearably hot?
I do stand corrected on one important point though: it appears it doesn't need any form of interrupt to cause it to lockout, i.e. using a hot water tap, it's
quite happy to lockout on its own after 10 or 15 minutes of use. It's done this several times now.
Video to follow.

 

[AlanLJ]

I've fired up the boiler this evening, and made a few videos of each startup; that being, it did of course go into lockout a few times, and
therefore require a reset several times.
The motor is hot, certainly, but perhaps not unbearably hot?
I do stand corrected on one important point though: it appears it doesn't need any form of interrupt to cause it to lockout, i.e. using a hot water tap, it's
quite happy to lockout on its own after 10 or 15 minutes of use. It's done this several times now.
Video to follow.

 

[AlanLJ]

Oh, well! Sadly my video (1 min) was too large to upload. Not surprised I guess. :-(
Scratching my head a bit now.

 

[SJB060685]

Motors will obviously be quite hot when running at steady state, could not tell you what sort of temperatures are normal though, lots of variables can effect that.
Running for 10-15 minutes though at a time suggests possibly a fuel issue. I think the temperature of the motor is irrelevant to your lockout problem now.
See if you can get a shorter video of flame failure and retry cycle, that would help.