Help with Bosch dishwasher not heating up

[Pat1812]

I’d appreciate advice on the following please, if anyone can help?

I have a Bosch dishwasher SMV40C00GB/44, FD 9612. It was fully working, but started to make a grinding sound which a check online suggested to be a fault with the pump bearings. I therefore replaced the pump with a new one and the grinding sound disappeared – all good, except that the dishwasher stopped heating water. It completes all the cycles but now with cold water, and ends with the infamous flashing tap symbol. I checked the new pump and found no problem with the heating element resistance, but to double-check, I put back the old pump which I knew was working. Same outcome – the dishwasher no longer heats the water.

Any ideas what is happening here? I’ve checked the flow meter on the inlet and that seems fine, and the controller board has no obvious signs of faults. What else could be wrong?

Many thanks for any suggestions as I have run out of ideas…

[electrofix]

did the small plug next to the heater plug get damaged during the change

are you sure you have the correct pump?

Dave

[Pat1812]

Thanks for the speedy reply Dave – much appreciated.

Yes, I am sure I have the right pump – the fact that the old one doesn’t heat up now also suggest to me that it’s something else.

And yes, the small white plug was a pain to remove and the wires may have been loosened in the operation. I suspected this might be an issue and did two checks: running the dishwasher with the white plug disconnected gave the same result as when it was plugged in (does a full wash okay but with no heat) – so perhaps there is no signal going back to the board? Second, I checked for continuity between each pin of the white plug and the board, but all were okay as far as I could tell.

Does that indicate anything useful?

Many thanks!

[electrofix]

the small white plug are the temperature sensors

Dave

[Pat1812]

Thanks Dave. So would you suggest I try replacing the lead and/or plug to the sensors?

I don’t think the leads are available separately, or are they? Bosch appear to charge £47 for the whole harness which is a bit steep for an experiment.

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