Baxi 105 e buzzing fan

[Monkeypowah]

Just changed the fan for a proper part cos it was screeching and a few days later the boiler fails, this time the fan is running freely but when it recieves whatever power (can't work it out on my digital multimeter) from the board it just buzzes like it's forgotten to spin and just is magnetically frozen with what seems like a 50hz buzz, it also attracts my screwdriver like an electromagnet, fan spins fine when plugged into mains.
I know I'm looking at a new board, or is this something weird anyone has come across before?
I'm worried of course the new fan has caused it, but how?

 

[Blooflame]

providing you're gas safe there shouldn't be a problem with warranty cos it's knackered. If you're not gas safe mate, you should get a gase safe engineer

 

[MJN]

[...] but when it recieves whatever power (can't work it out on my digital multimeter) [...]

What do you mean by that? If you can measure what the board is supplying you might be in a better position to determine exactly where the fault lies.

If you can pinpoint the fault to the PCB (which it sounds like given your direct-to-mains test - the old fan probably took out the driver stage as they're usually badly designed, not to mention unfused) I can recommend www.cetltd.com for a refurbished replacement (done on an exchange basis).

Mathew

 

[Agile]

I would never recommend a repaired PCB.

In any case a professional should not use them because they are not approved by the manufacturer.

Tony

 

[MJN]

I've never had a problem. Of course, there's refurbished and there's refurbished and I'd only purchase from a reputable company like CET as their knowledge of boiler PCBs is second to none.

Mathew

 

[Blooflame]

if I've read it right, there's voltage but it seems that it tries to turn butr won't if after u power off it spins, then u have aknackered fan.

 

[Agile]

No, you have not read it all!

He says the fan runs ok off the mains.

That implies the PCB is delivering the wrong waveform.

It would need a scope to look at it.

Tony

 

[Terrywookfit]

I would check you have a/c Sounds like it is d/c.

 

[Monkeypowah]

Thanks guys I'm am gas registered by the way, two things to mention ,i now find my meter is on the blink (works ok one everything except AC where it just bounces around, that's why I couldn't workout the fan voltage).
Secondly, the fan suddenly did it when on normal mains after I ran it for a good bit??!!
Seems I have a faulty new fan with the most unusual intermittent fault.

 

[Monkeypowah]

For future reference, I dismantled the fan and the little clip that holds
the bottom bearing in was loose, every now and then the armature was bouncing up and going into this weird mode while under power, take off the power and it span freely.
It was one of those jobs where a few odd readings lead you down the wrong road and the freakin boiler was on the floor next to the toilet and he had no light in the bathroom.