We have a built-in Bosch dishwasher in our kitchen, and it has started occasionally not really running well, and never finishing the cycle – it just sits showing 1 minute forever, with the drain pump running. We tried changing the drain pump, but it didn’t fix the issue. So, since it is around 7 years old we thought we’d get a new one … but we couldn’t find one we liked. All the good ones nowadays seem to have a third cutlery tray, which didn’t come out of the machine … it might look cooler, but just doesn’t seem to be a step forwards. What we really wanted was out current one, fixed. We’ve succeeded, at a total cost of £13, and about 30 minutes in the end, but it took quite a while to suss it out, and there was no complete guide I could find on the internet, so I thought I’d note down what we did for any future searchers.
The model number of our machine is SGV57T03GB/02 though having looked about a bit, I suspect that the details below will work for most machines that have a similar set of buttons on the top right hand side of the door. After a bit of internet searching and I found a site that said that the 1 minute issue was due to faulty relays – see here. The advice was to replace the control unit, and we found that this was possible, at £140 or so (plus VAT at a guess). Probably worth a go, but a better option if we were going down that route anyway was to see if we could change the relays.
The usual issue with relays is finding the right coil voltage, contact ratings, and mounting configuration, and initially it looked like this would be an issue. I had got used to the idea that I would have to fettle the controller a bit to get some relays that were at least the right rating fitted, and then I found what look like exact matches. They come from RS components, and their code is 683-9150 (see here). Key data is a 6 volt coil voltage, and 10 Amp AC rated contacts. A cost of just over quid each is hardly a bank-breaker, even if you need to buy them in 5s. Inlcluding postage and VAT it came to under £13
Fitting was pretty easy -basic soldering skills, a soldering iron and desolder tool, and a Torx driver are pretty much all you need.
First stage was to remove the front panel (the one that matches the other kitchen units). The top of the front door panel, including the control unit, comes out of the top front of the door, and only requires four screws to be removed – two in the middle at the top, and the first one down on each side. It then can be sprung out and swings forward.
Remove all the connectors, noting that each has a catch to stop it falling out that needs to be pushed in to allow removal. It looks like they are keyed so that they can only go in one place, but we wrote them down to ensure we got the correct order.
The control unit can then be removed from the top panel. There are three catches, one in the middle at the back, and one on each side near the top. It is a bit fiddly to get them all off – start with one side, pulling it back a bit, then the one at the back, then the last side.
The control unit is held closed by a series of catches between each button, and one more on each side. You need to take the plastic splash cover off the top first. then the front ones can be sprung with a small screwdriver, the side ones by finger. The circuit board is then held in with two catches, one on each side – with these sprung off the board can be removed.
The relays are pretty obvious. Our board has room for four, but only three fitted (the white blocks in the photo above). Presumably, one does the circulation pump, one the drain pump, and one the heater … but I’ve no idea which does which, and at less that £2/relay it seemed sensible to simply change them all (especially as I had a pack of 5). They are pretty easy to desolder. Two of the legs are bent to retain them, so they need freeing up to allow removal.
The relays I got were identical pin configurations, so replacement was a doddle – plug in and solder. – Visible as the black relays below. Then re-assemble and test.