Dishwasher not swishing: circulation pump gets no power

In article , Usenet writes

Oh yus. Especially if you're in the habit (as I am) of opening the machine mid-cycle to chuck something else in.

The machine filling, pausing, filling suggests it doesn't know where the water level is.

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Reply to
Mike Tomlinson
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In article , Usenet writes

No, they form a mains conditioner circuit, to stop rubbish generated by the motor(s) filtering back into the mains.

Switch '6 looks like some sort of breaker (thermal breaker?) Do triple check that.

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Reply to
Mike Tomlinson

Buying that dishwasher, we had in mind maintaining and repairing it ourselves. It's actually just right for us for that reason. Very simple, accessible, with standard parts at the right price. Ideally, we would have got a Chinese one, if it was available.

Anyway, it turns out that the problem wasn't the dishwasher's fault at all -- it was the self-tapping dishwasher "faucet" under the sink, that got clogged with rusty stuff over the past few years. It was barely a trickle! Turned off the mains, unscrewed it, cleaned it out and put it back again. Full power again!

I agree that that circuit diagram is not very helpful. Apart from everything being carefully scrambled and having no relationship to the physical layout, I think it must be for the top-end Beko model. Several features are missing from my bottom-of-the-range model. I discovered (from Beko UK) that the Beko DE2541F slimline dishwasher model only has a flow-meter for the water level control. That, and the flood protection device, I suppose. The flow meter is a lovely elegant little device, and you can hear it counting, by attaching an audible continuity tester to two easily accessible contacts on the flow meter.

As of this evening, the water fills properly now.

I'm guessing now, but when the incoming water pressure was only at a trickle, because the controller recognized that it was filling too slowly, the machine went into an unusual mode: filling for 15 seconds every five minutes, testing for the right water pressure. It never sent any mains voltage to the main pump.

Now that the water pressure is back, the controller does send mains voltage to the pump at the right moment. (It was *wonderful* at long last, to see the voltmeter -- attached by insulated crocodile clips to the motor leads -- jump from 0 to 240 volts!)

I *still* have a problem though! When the pump is meant to kick in, it doesn't, it merely "hums". My guess is that a month of not working, being tipped over on it's side, and having water drained from it, etc, has seized up the pump.

Does anyone know... what do do you turn in the pump or induction motor in an attempt to unstick it? Here's a very amateur picture of my machine's pump:

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With kind regards,

Sandy

Reply to
Usenet

kick

on

Make sure the pump CAN turn i.e. try to turn the impeller. There might be a foreign object , something displaced from flipping the unit etc. The crud in the water supply may be connected to recent freeze/ thaw. Breaks loose all kinds of scale and rust. Good luck

Reply to
malua mada!

Some of the Pump motors have a slot on the back of the shaft, that you can try turn (back and forth) with a screwdriver to free it up.

If it has a fan on the back, you can pull off the protective cover and try turn the fan by hand (just don't undo the long screws that hold the motor together!!!).

P

Make sure the pump CAN turn i.e. try to turn the impeller. There might be a foreign object , something displaced from flipping the unit etc. The crud in the water supply may be connected to recent freeze/ thaw. Breaks loose all kinds of scale and rust. Good luck

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Reply to
Peter Kolbe

What a bastard pump I have installed in my machine! The plastic pump "auricle" attached to the single-phase induction motor is designed to snap into position -- at the factory -- with plastic "snappy" fastenings. But it's also designed so you have to *break* the snappy things, and hence the auricle, if you try and remove it from the motor. And when the auricle is in place, you can't access all the screw/bolts that hold the motor together. A bastard pump.

The cooling fan blades are located at the back end of the motor, almost up against the back of the machine, where there's a metal plate holding a concrete ingot counter-weight (for when the front door is lowered), the inlet and outlet hoses, and the mains lead and anti-interference filter device. However, without undoing *everything* attached and entirely removing the back plate, one can unfasten the plate's screws and then pull back on it enough to see the back of the motor, and see the grey aluminium of the cooling blades at the back of the rotor.

There are twelve blades on my cooling fan (I marked one with red felt tip and counted). Using a *thin* wooden chopstick, I could push the rotor one cooling blade at a time. It's quite stiff, certainly not like a free spinning bicycle wheel, like I thought it might be. I must have pushed the rotor completely around about 20 or 30 times by now, in both directions. One direction *feels* slightly easier than the other, but this may be because of the radial asymmetry of the blades.

Is this how it's meant to feel, when you push the cooling blades around? The resistance is constant all the way around, so maybe this is normal...

...All advice welcome!

Now I have to go do the washing up by hand, again...

Many thanks,

Sandy

(P.S. At least the concrete ingot isn't made of tungsten.)

Reply to
Usenet

Usenet wrote:

Dear Usenet,

The dishwasher is operating normally again!

I screwed the back plate back on, and connected the dishwasher up again to the water input and output. I ran it on the 15 minute pre-wash no heat cycle, fine. Then a 30 minute, 35 degree heater cycle with three changes of water, fine. The rotating arms took a while to clear themselves of little dried cloggy bits, but at the end they were going round like they always have. Swishing again!

What a journey I feel I've been, through! It so happened that there wasn't anything wrong with the dishwasher per se; the fault in my case was the slowly gunked-up water supply all along. But it has been incredibly worth it -- taking off the panels, seeing the workings, testing with the multimeter, and looking over the whole works. Now the dishwasher, washing machine, power wash, and eh even the power drill, and jigsaw, and anything else, are not mysterious black boxes anymore!

-

A note about Haynes' "The Dishwasher Manual" by Graham Dixon:

This book leaves much to be desired. It is not up to the standard of the world famous car manuals upon which Haynes' reputation rests. OK, the Haynes label gave me the initial encouragement to make me think I could repair my dishwasher, but beyond pictures of actual sub-components (most of which come from Dixon's earlier "The Washing Machine Manual"), the book hasn't been much help. More of a hindrance really. To be honest, the book seems not even half finished. The index of only several dozen entries doesn't fill a single page. Many of the diagrams have no labels and are not given a reference number. Repeated photographs of the same component, but with different comments, are seemingly there to bemuse the reader and help pad out the book. There are many infuriating chapters of one, or one and a half patronizing pages. The flow charts (speaking as a programmer myself) -- which are meant to help organize complexity -- are instead there to make the simple seem more complex, are all badly titled, unlabelled, completely moronic and waste yet more pages. And here's another what for: the chapter on pumps and motors is all about the goddamed potted physics, and the pros and cons of various approaches to motor design. No mention of how easily they can seize up, or how to go about unsticking them. There's a corporate engineering drawing of a "generic rotor" with cooling blades floating in space, but without anything else, no context! Where's the explanation on how to test if the motor's working, in situ? Or about taking care when manipulating big hose clips, or lubricating the inside lip of the hose with a smear of washing up liquid when putting it back on, of NOT using grease, which will corrode the rubber, or checking out the auricle's side exit first?

I hope someone in the near future writes a *real* Dishwasher Repair and Maintenance Manual. These are, after all, increasingly the times when we're going to badly need one.

With kind regards and best wishes to all,

Sandy

Reply to
Usenet

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