Boch Wash+Dry Exxcel 7/4 dryer fan not working

[gibbobloke]

Hi

I have a 3 year old Bosch wash+dry Exxcel 7/4 (model nr WVH28360GB) which stopped drying around Christmas 2017.  Having bought the machine from Wash-House 3 years ago I have all labour included for any repairs abd so called out an engineer.

He pulled out a large handful of lint from the fan but could not get the fan to stay running during a drying cycle  - it would work for say 5 mins and then stop - thus the heating element cuts outs would pop.

A month ago the machine then stopped heating the water, after being informed repair costs for parts would be in the region of £300 (I stopped coughing 10 minutes later) I said thankyou and showed him the door.

So - having a reasonable (but limited) understanding of electronics I decided I would have a look.  I tested the water heating element which seemd ok, stripped out the main pcb and cleaned everything and have managed to get the machine to heat water again, but not get the fan to work.  There is continuity across the coil so I think it could be cut out or relay related (assuming that the large 4 or 5 square boxed on the main PCB are indeed relays).

Noting that there are at least 4 or 5 cut outs and at least the same number of sensors in the machine - anyone else had this problem and managed to fix it?

Kr

 

Andy

[Whitegoodshelp (Andy)]

A dryer fan motor cutting out could be caused by a faulty connection (although it should be quite random), or it's overheating due to some restriction. If there was a blockage inside the fan housing or where the fan is trying to blow the air is blocked it could overheat. Or maybe just a fault on the motor. Any TOC cutout should be embedded in the windings of the motor and is rarely replaceable separately.

[gibbobloke]

Hi again,

 

Fast forward to today and after ordering a replacement fan off Spares2Repair I now have a fully functioning machine.

However

I did note that the aluminum duct was full of corrosion and what looked like washing powder deposits (may have been corrosion) and the duct was very damp!!

So I am thinking about inserting some coarse gauge filter material into the two holes from the drum to 1. stop lint from knacking the fan again and 2. to try and keep the duct dry.

 

Anyone else tried this or had a better idea?  

 

Andy

 

[Whitegoodshelp (Andy)]

14 hours ago, gibbobloke said:

So I am thinking about inserting some coarse gauge filter material into the two holes from the drum to 1. stop lint from knacking the fan again and 2. to try and keep the duct dry.

Tbh I can’t see that working. The corrosion and deposits of limescale or detergent are most likely caused by steam from the wash rising up through the vent in the top of the door seal and condensing. 
 

That can’t be stopped. You need good airflow between the fan and the laundry inside the drum and anything that reduces that would be bad. Anything that didn’t reduce airflow would be ineffective for your purpose.

Anything like that added would also just trap stuff and cause a blockage unless I’ve misunderstood what you mean. Ultimately I believe washer dryers have a design flaw or weakness that is inherent and they all suffer from it. That is, the chamber you mention gets coated in limescale, detergent and lint, that eventually causes breakdowns and blockages.