Hello,

My dishwasher stopped working. I posted to the ukwg web site and
someone suggested that water ingress had seized the bearings on the
motor.

When the motor was in situ I could not turn the impellers. Once I
removed the motor, I could turn it but it was hard work. With the
impellers removed, I could not turn the spindle.

I thought if the motor was seized it would not move, so I am puzzled
how I managed to turn it but perhaps I was applying more torque than
the motor could (is this possible?)

I've only had one person help on ukwg, so I thought I would post here
for a wider audience. To be fair perhaps the repairmen are out at
work.

I took a few photos which I uploaded:
http://tinypic.com/r/fnegx2/6
http://tinypic.com/r/sp9qbb/6

There didn't seem to be any obvious water ingress until I removed all
the impeller assembly and then I found a sandy/dusty substance. It is
not rust. What is it? Scale? Some sort of corrosion?

It was suggested that the IWMS might be a problem in the future and I
would be better buying a new machine. There are some deposits in the
IWMS; I believe they are mould. It is in the water inlet side of
things, so it is not dirt from the washing.

http://tinypic.com/r/awtdno/6


Thanks,
Stephen.

It happens that Stephen formulated :
Hello,

My dishwasher stopped working. I posted to the ukwg web site and
someone suggested that water ingress had seized the bearings on the
motor.

When the motor was in situ I could not turn the impellers. Once I
removed the motor, I could turn it but it was hard work. With the
impellers removed, I could not turn the spindle.

I thought if the motor was seized it would not move, so I am puzzled
how I managed to turn it but perhaps I was applying more torque than
the motor could (is this possible?)

I've only had one person help on ukwg, so I thought I would post here
for a wider audience. To be fair perhaps the repairmen are out at
work.

I took a few photos which I uploaded:
http://tinypic.com/r/fnegx2/6
http://tinypic.com/r/sp9qbb/6

There didn't seem to be any obvious water ingress until I removed all
the impeller assembly and then I found a sandy/dusty substance. It is
not rust. What is it? Scale? Some sort of corrosion?

The rusty coloured white dust is limescale, so it looks as if the shaft
and bearing at least have been sat in water. Whether or not it should
be I don't know, but what I can say is that the motor shaft should turn
quite easily by hand. The fact that it doesn't, suggests the bearing(s)
have been damaged. You may be able to pull the motor apart and just
replace the bearings sourced from a bearing supply company, but would
need to sort out the leak before reassembly.

That type of motor will not produce much torque from zero RPM, its best
torque will be at or close to full speed.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

On Wed, 22 Aug 2012 18:31:27 +0100, Harry Bloomfield
wrote:

The rusty coloured white dust is limescale, so it looks as if the shaft
and bearing at least have been sat in water. Whether or not it should
be I don't know,

Thanks for your fast reply. I did wonder if it might be scale but I
thought the dishwasher softened its water, so I thought there would
not be any scale to precipitate?

The motor is not designed to sit in water; it is under the machine
exposed to the room, so it could not sit in water unless it flooded.
Beneath the motor is a tray with a polystyrene float which should cut
off the machine if the machine did flood.

I think that the rubber seal between the sump and motor has allowed a
drip to escape from the sump but this should be soft water, so I am
puzzled how it has deposited scale.

but what I can say is that the motor shaft should turn
quite easily by hand. The fact that it doesn't, suggests the bearing(s)
have been damaged.

Thanks. I hadn't held a motor before so I had nothing to compare it
to. It certainly seemed stiff but I wasn't sure if they were all like
that.

There is also a split in the spindle. I don't know whether that is
significant?

You may be able to pull the motor apart and just replace the bearings
sourced from a bearing supply company, but would need to sort out the
leak before reassembly.

Perhaps getting new bearings would be cheaper than a new motor (£100)
but although a dishwasher is not a life or death machine, once you
have got used to one, you miss it when it is not there. It might be
quicker to pay for a new motor and get it delivered the new day rather
than spend days looking for somewhere that could repair it. This motor
comes with new seals and a new impeller, so hopefully the new seal
would fix the leak problem.

That type of motor will not produce much torque from zero RPM, its best
torque will be at or close to full speed.

Thanks. I didn't know that; I've learnt something new today.

Thanks again,
Stephen.