Main Oven Fan faulty (Bosch HBN435AGB)

[Roy*]

The fan rotates slowly or not at all?

Basically it’ll start to spin free if you give a push and actually rotate for a while at a slow speed. This has been happening intermittently for the last year but now as it’s Christmas it’s stopped working. I removed the shield plate to ensure nothing was stopping it but it seems to be fine and rotates freely when you give it a push. To me it’s as if :

a)The motor is rotating but not rotating the fan due to some sort of drive/clutch failure (I’ve no idea of construction so this could be very wrong)

b)The fan motor is not rotating or rotating with little power due to it been ‘worn out’?

So I’m looking for advice please. Is it a case of new motor and fan (seen them online around £75) and get my sparky neighbour to fit it for me or is it easy enough to fit myself?

Maybe it just needs some maintenance or reconditioning?

I realise I’ll not get it sorted until after Christmas so we’ll have to cook without the fan assist, then that’s my fault for not taking the occasional fault seriously.

It’s 5 year old built in double oven and cost £700 so I don’t really want to buy a new one. I’d of thought a Bosch product would have lasted longer than 5 years, but then I guess they’re designed only to last as long as the guarantee……..

Thanks

Roy

 

[tiredengineer]

The easy repair is to replace the fan motor assembly.
If you're game you could try stripping the assembly out, taking it to bits, lubricating the necessary parts and rebuilding it. Might work, might not.
It's direct drive so no clutch or gearbox.
Hint. The screws holding the fan in place are accessed from the oven cavity.
Hint 2. The fan blade is held on by a left hand threaded nut.


Unplug your appliance before working on it.

 

[Roy*]

Cheers tiredengineer

I’ve seen the motor mounting screws on the inside and have taken the fan nut (reverse thread) off. As it’s a built in oven though I have to remove it from the cavity to get to the back, right?

Any top tips where to buy a new motor from or is ~£70 the going rate?

I’m not sure lubricating will help it’s almost like the motors on the way out, you know like brushes or whatever you call all that the stuff in an electric motor?

When you switch it on it will try to rotate but it’s not got any power to rotate the fan but push it and if flies round with no resistance…

 

[tiredengineer]

No brushes in these motors. Induction coil.
Yes you'll have to pull the oven out to get the back off and gain access to the fan. A table the correct height is handy, failing that any table and a mate to help lift it.
Sorry, no idea about prices or where to get them.


Unplug your appliance before working on it.

 

[Roy*]

thanks tiredengineer, sounds like a new motor.