Miele H4780BP wall oven not heating

[crane5]

Hi Guys,

I was wondering if anyone had experience with a Miele H4780BP wall oven not heating?

There are no fault codes in the service menu. Starting a bake cycle will switch the fan on but none of the 4 elements. The unit is getting 240v measured by multimeter between the L1 and L2 screws at the terminal block on the unit.

Is there a door sensor that would prevent the elements from switching on? I would think the fan would also refuse to switch on if the door sensor is showing open.

Pulling the unit out of the cabinet for testing caused normal operation with all elements heating properly, so the elements are good. After 2 days back in the cabinet the oven again presents with no elements heating but the fan running.

Can anyone advise what might be the likely cause preventing the elements from switching on? Any ideas very appreciated.

[LI-NY Tech]

If moving it made it work I'd be looking for a wiring problem. Check the junction box where the house wiring connects to the oven wiring.

[crane5]

Thanks. I was thinking a loose connection somewhere might be the cause. At the breaker panel everything is tight. The junction box is hard to access deep behind the cabinet but the problem might be a bad connection in there.

The LCD display and convection fan always work so the oven seems to get 120v reliably. If the second 120v leg drops out intermittently due to a loose connection in the junction box, would that cause no elements heating but the convection fan to still work?

When the unit was pulled out of the cabinet and worked normally there was some extra pressure on the door which is why I'm wondering about the door switch in the upper right corner of the frame. If the door switch is reading open would that cause no elements but convection fan working? Or would door switch open cause no elements and no convection fan?

[crane5]

The connections in the junction box seem fine. The receptacle and plug look good, the power cord going back to the terminal blocks seems undamaged.

Manually pressing the door switch turns the convection fan on/off so the door switch seems fine. Still none of the elements are turning on.

After the oven was pulled and put back in the cabinet it was working normally for 2 days in the cabinet then the elements stopped heating again without any movement or changes.

What could be the likely cause of this behavior?