Kenwood dishwasher fun (KDW12ST3A): Part One

I bought my Kenwood KDW12ST3A dishwasher from Currys about 8 years ago. If memory serves, it cost £219 in the sale.

I bought it because my Candy dishwasher had exploded a few days earlier and I was desperate to replace it (and for that you can read that the pile of unwashed crockery in the kitchen sink was beginning to hum). The Kenwood was/is stainless steel and looked really nice in the corner of my kitchen. It was a few years later that I came across a bunch of reviews on the internet and the general view was that this dishwasher was a cheap-shit piece of chinese tat that was undeserving of the Kenwood brand. Many people had many problems with this machine. Alas, this had not been my experience and my dishwasher ran without fault for 8 years. And then a couple of months ago the fun started.

The first problem was an evident overheat - at the end of a particular wash cycle the contents of the dishwasher were roasting hot. At the next use the main circulation pump refused to run and so the dishwasher returned an error. For the first time ever, I took my dishwasher apart. At this stage, all I wanted to do was take a look inside. So far as the pump goes, it is a fairly simple motor arrangement. I was able to attach a screwdriver to the end of the pump's main shaft and discovered that the pump was jammed. I imagine it was some detritus or something, because I managed to free it by gently turning the shaft back and forth. I also noticed that the large starter capacitor on the pump was looking out of shape so I removed it and using my ESR meter, established it was toast. I ordered a new cap from CPC (a "Ducati 4.16.10.08.64", CPC part CA05818), and once fitted, and with the pump removed, cleaned, and re-installed, the dishwasher was up and running again. That was in June.

Fast-forward to the end of July and the second problem manifests itself. I don't know whether this was connected to the first problem but the dishwasher was failing to heat - the water inside was stone cold - and was returning an "E3" error. According to the manual, the E3 is a failure to heat and could be caused by a number of things including broken thermostat or broken heater. Some research on the internet also points to a possible broken control board or broken pressure safety switch.

First check was on the heater. Apparently, if the heater reads 29 - 31ohms resistance across its terminals, it's fine. Mine was fine. So, there being basically no information about the thermostat in this machine, I just replaced it (espares part ES1560613). This made no difference at all. I then looked at the pressure switch. This seemed OK and I was going to leave it bearing in mind the cost of a replacement (espares part ES1560552) but having actually inspected the device, I discovered that the only moving part was the microswitch inside it. The switch is an Omron D3V-16-3C5 and can be bought from Farnell for about 65p. Here's a few photos of the part in situ, and replacing the old switch with the new one. Needless to say, it made no difference....

So, what next? I took the front door apart to gain access to the control board. I've added some photos of this below. What I was looking for was signs of overheating in the board, My logic was that if the board is faulty, it might not be switching the heater on. Now, there was some evidence of overheating on the main switchboard, but the board with the relays on it looked fine. Whilst the door was off I took the opportunity to check continuity in all the wiring and it was all fine. So, I took the plunge and bought a new control board set. These are hard-wired together so its a case of all or nothing (espares part ES1551964). Now, this wasn't cheap but I'm still a long way off the cost of buying a new dishwasher. When the part arrived today I was hopeful.

Here are some photos of the removal process. To get at the little board that lives near the on/off switch, the actual door handle must be removed (unscrew the two machine screws that I've highlighted, so that the plastic tray which contains everything can be slid down the inside of the door).

The next pictures compare the new parts with the old. The old part in each image is on top. Interesting date codes on some of the PCBs...

 And now it's all back together it's still not working properly. I'm still getting the E3 error but the water is being heated a little. It's far from hot (hence the E3), but it is noticeably tepid. What is going on? I'm going to have a think about my next move.

More soon, no doubt...

D