CBCONW12 – Oven Won’t Switch On

[yucca]

Hello Folks

Just after a bit of advice trying to diagnose which component in a Currys Essential Built In Oven CBCONW12 (Conventional not fan assisted) has failed.

The over won’t power on. It doesn’t matter which function is activated, the LED light indicator does not illuminate and the elements do not heat. The cooling fan does not turn on either.

I have checked the following:

1. There is power going to the terminal block at the back of the machine so I know it’s not a fuse outside the machine
2. The rotary thermostat control was replaced about a year ago but just in case I removed the spade connectors from the reverse and placed a continuity tester across them which buzzes as soon as the thermostat control is rotated indicating that the switch inside is working
3. I have placed a continuity tester against the top element (which appears to comprise two elements in one unit) – the continuity test buzzes for each pair of spade terminals – I assume this is correct and that there is no break in the internal elements
4. I have placed a continuity tester across the terminals of the bottom element but that didn’t buzz (there appears to be a resistance of around 45 ohms)
5. I have placed a continuity tester across what I think is the temperature limiting switch and that buzzes so that shows the switch is not stuck in the open position
6. When the function switch is set to heat the lower element and the thermostat is increased, there is no voltage across the spade terminals to the lower heating element
7. The cooling fan does not turn on at any point

To me it looks like there is a component in series that is preventing power from being sent to all components – the only thing I can think it could be is the temperature limiting switch. Other than that, I guess it could be the rotary function control switch. From examining the rotary function control switch, the axle has “protrusions” which I think break a circuit when they point downwards.

Also, it looks like the components share a common neutral line. I’ve tried to find a wiring diagram but not been successful. Given how much time I was there I reckon I could have produced one myself but just got fed up.

Any advice would be gratefully appreciated.

Thanks

[electrofix]

ok you say you have power

you have a live but do you have a neutral ?

Dave

[electrofix]

cant be much its a very simple oven

Dave

[yucca]

Hi Dave

There was 240 volts across the live and neutral connections coming into the oven. Unfortunately I didn’t do a continuity test to check whether there was a break in the neutral line. So many of the cables were the same damn colours! Unfortunately, I’m not at the oven today so can go and check now.

Regarding the rotary function control switch, is the intention to connect the brass terminals 1 to P1, 2 to P2 etc when rotated? I could see that some of the brass terminals were joined together e.g. 1,2,3 might have been connected simultaneously.

[electrofix]

the neutral goes into p1 and will connect to 1 when rotated
check this

Dave

[Author]

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