Diplomat Dishwasher ADP8322

[ferengi]

Dishwasher has been playing up. Wouldn't take in water, kept pumping until it gave error (4 flashes). Found failed inlet valve so replaced. Now it runs through full cycle but arms do not spin. Sounds like it's pumping water round the system but just not getting any oomph in it. It is hard to hear exactly 'cos the water heating is bubbly noisy.

Checked the pump for connectivity (passed) and cleaned it out (was greasy round the impeller) but no change.

Any ideas?

D

 

[ferengi]

These are the numbers off the label, if they're any help...

8545 000 15819
33 0602 001158

Can anyone tell me what resistance reading I should get across the terminals of the circulation pump?

Any other ideas, folks?

 

[zipper]

Hmmm...I seem to remember seeing these numbers someplace else?
4 flashes (F4) indicates a pump issue, it seems very strange you found a defective inlet valve, that would normally prompt an F6 error. What was wrong with the valve?
Although your machine says Diplomat on the door it is in fact manufactured by Whirlpool. A few things to suspect would be: spray arms blocked, pressure loss, wash motor capacitor faulty, impeller jammed/defective, or a motor fault. Before condemning the wash motor first determine it is actually running, then check the spray arms are not blocked. There are a couple of other things to look at but check these first.

 

[ferengi]

You're a perceptive one!

I put a multi-meter on it and got infinite resistance so swapped it out. When I did that it happily ran through a cycle (albeit that it didn't spin/ wash) without giving an error. Weird, huh?

What's the easiest way to be sure if the pump is running? Can I run it with all the panels off? That way I can eyeball the pump I suppose (although it's not easily seen clearly when the machine is not on its side). How would you do it?

I'll have another look at the arms. I know the arms themselves are clear but perhaps the system feeding them...

Regards

D

 

[zipper]

The inlet valve resistance should measure around 3.8k ohms (3800 ohms).
Do you mean checking the drain pump or the wash motor? You can observe if the wash motor running by removing the right hand side plate. But you can get easy access to almost all the components by lying the machine on its back & removing the bottom plate (2 screws/2 plastic clips). You will see the drain pump attached to the left hand side of the sump (twist fitted). Take it out & check for pieces of glass etc. There is also a rubber non return flap fitted in the small plastic sump pipe branching off the sump very near to where the drain pump twists on (this can sometimes get clogged/jammed).

 

[ferengi]

Well, there you go, I was thinking that there was only one pump for draining and washing! So the pump I have taken out and cleaned was the drain pump and, because I have been lying it on its right hand side and removing the bottom and left side covers for access, I've never even spotted the wash motor. I'll check it out later along with that rubber non-return valve

If the wash motor has failed would it not produce an error?

 

[zipper]

You would think so but it isn't listed as a separate error code, it may however trigger another code. Error codes are often a good help in identifying a particular problem but they can also be annoyingly misleading sometimes. F4 usually turns out to be a drain issue, either on the machine itself or the plumbing. Think about it this way; if the machine can't evacuate water it won't fill either.

 

[ferengi]

Is this the wash motor/ pump?

And is that a heater to the left of it? If not, what is it?

D

 

[ferengi]

Btw What kind of resistance should I read across the wash pump?

 

[zipper]

Yes; inline heater to the left and wash motor on right side of picture. BTW from the photo it looks like there might have been water leaking on the bottom plate (or is it just a reflection?). If it is leakage one possible culprit could be the seals in the wash motor. At 25C: Heater res. 25 ohms. Drain pump res. 146 ohms. Wash motor res. (note this has 2 windings) from a slightly fuzzy memory you ought to get something like 70 ohms & 48 ohms (I can't remember if they have 3 or 4 terminals). There is a 4 uf capacitor mounted on or near the blind side of the wash motor.
To get easy access to all the components lie the machine on its back & remove the bottom plate.

 

[ferengi]

You're right about the water marks...but they're old; several years ago I had a backup caused by an external blockage. There doesn't appear to be any leakage now though.

What's the point of two windings? Btw the plug which you can see in the forefront only has two terminals? Across those terminals I am getting only 30 to 31 ohms. I had the motor out and the impeller was a bit dirty/ gritty but not bad. I've noticed though that the plug for the terminals is a bit burnt so it's obviously had a 'moment' at some point. I'm going to cut it off and put spades on it in case it's the plug making a bad connection.

Also, looking at that picture, I've just realised that I've put the motor back in a quarter turn out (CW) so I'll need to redo that!

 

[zipper]

Yes I see the 2 point plug but this motor has to have min 3 terminals to enable a 4uf capacitor to be connected between the two windings. The other connections will be at the blind side of the motor where the capacitor is fitted. If you pull off the motor connection plug what resistance do you read across the two? Single phase motors of this type have a run winding & a start winding. When switched on both windings are in circuit until the motor approaches full speed, at which point the start winding cuts out (otherwise the motor would burn out very quickly). The capacitor provides a start-kick but once discharged it effectively disables the start winding.

 

[ferengi]

ok doke, I'll check it out and get back to you later on.

Cheers

D

 

[zipper]

Burnt connections sound a bit ominous! I have seen bad/burnt heater connections but rarely on a wash motor. As you suggest replace the connections with spades. It is hard to see from the picture if it will be possible to observe the wash motor rotor actually spinning. But hook up the machine with the right hand side plate off. Run a program & try to ascertain if the wash motor spins or if it just stands there making a humming sound. It it hums without spinning then it is either down to a bad capacitor, defective motor windings, or jammed impellor.
But back to the start...F4 is almost always a drain issue.

 

[zipper]

As an afterthought I suppose you could do it another way. Rather than go to all the trouble of connecting everything again & running a program to find out if the wash motor is good or bad you could try this:
Make up a flex with spade terminals & a fused plug. Put a couple of pints of water in the machine. Close the door & hotwire the wash motor (don't forget to find a good earth point on or near the motor). Stand well back & switch on briefly to see if it runs/washes or just stands there buzzing.
You could also test the drain pump in-situ in much the same manner (remember to lift the drain hose & put it over the sink, or in a bucket).