Kenwood dishwasher fun (KDW12ST3A): Part Four

Right, I think I've finally cracked it. Before I get to that, I should say that having pondered the issue since my last failed attempt, I'd decided that the problem was with the main circulation pump even though it appeared to be operating normally (pumping!) and that the resistance across its terminals was within the specified range (78 - 100 ohms).

My theory went something like this: with the machine running normally, the PCB switches the heater on. However, that little switch that I replaced a few weeks ago must be depressed before the heater will actually work. It is the water pressure created by the main pump that causes the switch to be depressed. This is a safety feature in the event that the main pump fails, or there is a water leak, during the heating cycle. It prevents the heater from boiling or over-heating itself. Important, because my machine has no actual temperature sensor on it...

So, I decided that something must be serving to reduce the water pressure in my machine. It can only have been a slight reduction because both the top and bottom arms of the machine were spinning during the (many) test programs I had run. However, it was enough of a reduction that the little switch wasn't being depressed with the result that the heater was never actually switching on.

Tonight I removed the main pump which, frankly, was a pain in the ass. The non-reusable clips the manufacturer has used on all the tubing are nasty to get off, particularly as I was trying my best not to damage the tubing. Anyway, I got the pump off and inspected it. Some photos with commentary:

Here is the pump in situ. Note the nasty pipe clips...

Here is the pump on my coffee table, And what is that I can see in the impeller housing, directly under the sump drain connector?

Can you see it? It looks like a slice of water chestnut. It's actually a piece of rectangular plastic. I couldn't get it out of any of the connections. So I removed whatever the hell thing is attached to the housing.  

And lo, the piece of plastic is the same shape as the hole left by the thing that was attached to the housing.

Just like that...

Ah, I see. It's a flap that is supposed to be connected to that thing I just removed.

And here is a close up of the thing. Turns out it is a "FCD-90A" solenoid valve. It turns out that when activated, that flap serves to close of the water supply to the bottom arm in the dishwasher. It is this that delivers the "half load" facility on the dishwasher (which, incidentally, I have never used. Ever).

It's supposed to look like this.

And this.

I don't intend to replace the valve. And I can't put everything back together tonight because I have no jubilee clips of the right size. Roll on tomorrow for the grand re-assembly. Will I have my dishwasher back?

More soon, no doubt :)...

D