SMV53M00gb/21 not heating water

[andcro]

Hi,

I’m looking for some detailed help. I’ve got a Bosch integrated dishwasher that has recently stopped heating water. It doesn’t display an error or beep code.

I immediately thought it would be the heater pump, but I put a meter across the two contacts where the larger red wires plug in and I get around 20 ohms – which seems about right.

There are 2 other connectors – the 3 connector where the pin purple ribbon cable fits appears to have consistent resistance across each of the 3 wire options – so again I think it might be ok.

The 3 pin Grey ribbon cable has only continuity across the middle and right connector at 14kohms- I briefly got 28kohms across one of the other combinations – but I’m not sure if this is right or not.

I went back to the main control module – I checked voltages on the connectors for the red cables, the right was 120VAC – but only back to earth (which is strange) the left was 0 VAC.

With the plug disconnected and the dishwasher running – it comes up with an E09 at the end of the cycle – this I think is as expected. With the plug connected – it just operates without error – but no heat.

So – it could be a relay on the control module as I’m not getting voltage on one contact, or it could be a thermostat not telling the control module to switch on the heat?

I’ve looked at the exploded parts diagram and can’t find an separate thermostat, so is it correct to assume it is built in to the heater pump assembly?

The dishwasher is around 8 years old and I don’t mind replacing the heater pump or the control module but I’m not keen to replace both as it’s probably not a good investment.

Thanks in advance for your help.

Andy

[Martin]

Re: SMV53M00gb/21 not heating water

Heater relay on the board primary suspect.

[andcro]

Re: SMV53M00gb/21 not heating water

Thanks Martin.
I found the relay details – but stopped short of unsoldering it and testing it as it needs 240v to switch it (chickened out!) – sounds like I might have to bite the bullet and do it.

Any suggestions on where to buy the relay if it is duff?

Thanks

Andy

[Martin]

Re: SMV53M00gb/21 not heating water

RS or Farnell

[andcro]

Re: SMV53M00gb/21 not heating water

Well – I pulled the relay and tested it on the bench and it works fine, so this leads me to think it could be that it’s not getting the instruction to heat.

Gutted really as found a supplier who were really helpful in matching a new relay.

Is the thermostat built in to the heat pump on these? I can only find 2 other sensors on the diagrams – one is a turbidity sensor and the other I can’t tell – perhaps water level?

[electrofix]

Re: SMV53M00gb/21 not heating water

There are 2 sensors on the heater element inside the motor

Dave

[andcro]

Re: SMV53M00gb/21 not heating water

Thanks Dave – so, sounds like replace the heat pump assembly then?

[electrofix]

Re: SMV53M00gb/21 not heating water

don’t jump to conclusions

you need to measure the sensors (NTC’S) not sure of the value. think martin has tech access so if he reads this he may give you some resistance values

of the ntc’s are ok it could be wiring or the main board at fault

Dave

[andcro]

Re: SMV53M00gb/21 not heating water

I’ve continuity tested the wiring between the control module and the heat pump – all good. I realise there’s plenty on the control module to go wrong so I can’t test all that.

It’s the NTC’s I’d like to locate – I’d come to the conclusion they must be in the heat pump assembly, but it’s only my process of elimination.

If it was newer I’d take a punt – but it’s about 8 years old and I feel I need to be careful throwing parts at it – it could soon exceed the price of a new one.

Appreciate you guys helping.

[electrofix]

Re: SMV53M00gb/21 not heating water

not sure if they are all the same but I split one a while ago for interest

the picture is the heater

NTC’s are arrowed

Dave

[andcro]

Re: SMV53M00gb/21 not heating water

The connections look the same – did you find out what the smaller connectors on the right were for?

I wonder if thats the NTC?

[electrofix]

Re: SMV53M00gb/21 not heating water

you beat me to it

altered the picture

Dave

[andcro]

Re: SMV53M00gb/21 not heating water

I checked the continuity on these – but I’m not certain of what it should be –
The 3 pin Grey ribbon cable has only continuity across the middle and right connector at 14kohms- I briefly got 28kohms across one of the other combinations – but I’m not sure if this is right or not.

[electrofix]

Re: SMV53M00gb/21 not heating water

think centre pin is common so I would expect same reading between common and either of the other 2 pins

when you got 28k its probably between outer pin which means each NTC is 14K

Dave

[andcro]

Re: SMV53M00gb/21 not heating water

Just double checked – you are spot on, 14k from the left to middle – 14k from the middle to the right pin – 28k across the outer pins.

Damm! Hoped that might have been the problem.

[Author]

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