Smeg DF410S Diswasher – Circulation pump not working

[Sheffield10]

My Smeg dishwasher has an intermittent problem with the circulation pump where sometimes it does not work for the whole wash cycle. I have removed and checked the circulation pump and other components several times, and once reassembled the dishwasher usually works for a cycle before the pump fails to work again. No fault codes are displayed. I have checked the following:
– checked the circulation pump and pipework for debris/obstruction – nothing found pump spins freely
– checked the resistance across the pump terminals (approx 45 ohms), checked there is no short to earth – there isn’t
– checked the starter capacitor resistance – rises from approx 4K ohms to infinity in a few seconds
– checked the heater element (approx 30 ohms) – water heats, so confident this is working
– checked the temperature sensor in the door – shows falling resistance with increasing termperature
– checked the door interlock – both microswitches showing good electrical contact when door latch in closed position.
– The fill valve and emptying pump are both working fine.
Given how expensive a replacement circulation pump is – I really don’t want to buy one if there are other faults I can check for first – any ideas please?

[kaibart]

You have only the wiring to in the door to check if thats ok its more than likely a wash motor

[Sheffield10]

kaibart wrote:You have only the wiring to in the door to check if thats ok its more than likely a wash motor

Thanks for the reply – I assume the check on wiring in the door is to confirm the wash motor is being fed a voltage when it should be, is that correct. I should also have added, that I can hear a buzzing noise coming from the region of the wash motor during the wash cycle, when the wash motor should be running. Is it possible that the capacitor is faulty even if it is showing rising resistance when it is tested – or shall I just give in and try a new wash motor!

[tubafan]

Sheffield10 wrote:

Thanks for the reply – I assume the check on wiring in the door is to confirm the wash motor is being fed a voltage when it should be, is that correct. I should also have added, that I can hear a buzzing noise coming from the region of the wash motor during the wash cycle, when the wash motor should be running. Is it possible that the capacitor is faulty even if it is showing rising resistance when it is tested – or shall I just give in and try a new wash motor!

My bold above – yes it could still be faulty. For the small cost of a generic motor capacitor of the right uF rating I’d give that a go before changing out the whole motor assembly.
When my Bosch dishwasher had the same issue a few years ago I gave the motor a flick with an insulated tool (lolly stick!) and it started running. On that basis I got a new capacitor and it did fix it.

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