Worcester Danesmore 20/25 fault

[Crandart]

Had this boiler for 18 years and it's been no problem. But today it keeps locking out. When you reset it there is a buzzing noise coming from it and the fan doesn't start and it then trips out again. Ideas on where to start looking or how to deal with it.
Cheers

 

[holty]

seized oil pump would be first port of call. but obviously not the right answer without a proper diagnosis. any how just changing the pump alone would require an oftec or compotent engineer, with the right equipment to calibrate. otherwise very poor performance or worse could occur.

 

[oilhead]

Try a capacitor first.

 

[rpevans]

I second oilhead, try capacitor first.
Rich

 

[Boilerman2]

Capacitor if that doesn't work the TF830 Control box is the next most likely suspect!!

 

[holty]

personally first thing i would do. would be to take the oil pump off. see if it rotates etc. start the burner and see if the motor spins. pretty simple really that rules out one or the other.

 

[Crandart]

Tried the reset the following morning and away it went and no stopped since, does that still point to the capacitor?

 

[Burnerman]

That would still get my vote......the capacitor just tells the motor in which direction to spin.
John

 

[rpevans]

I thought that the capacitor also gave the motor a bit of extra 'oomph' to get it going?
Rich

 

[Burnerman]

It does, Rich - with these brushless motors all they do is oscillate at 50Hz (the rotor that is) rather than actually spinning if no start winding or capacitor is present.
The cap gives it that bit extra shunt to get it spinning.....you can do the same by tweaking the rotor spindle yourself but the motor will start slowly.
I'll leave the exact science to someone else!
John

 

[Terrywookfit]

A single phase a/c supply creates a pulsating magnetic field.
A/C motors require a rotating field to start.

The capacitor is wired in series with the start winding. This gives a 90deg phase difference between the currents in the start and run winding .
When the motor is turned on, the different magnetic fields in the two windings create the turning force to run the motor.

 

[rpevans]

Thanks guys.
Every day is a learning day.
Rich