NEFF C17MR02 Oven tripping RCD

[BlueVan]

6 year old Neff combi Oven/Microwave trips the Schneider 30mA EZ9R33263 RCD on our distribution board when we try to use the convection oven but runs the microwave fine, even on MAX setting.

One of us (not me) slightly nuked one of those part-baked baguettes using the microwave but hardly any smoke... Come on, it's an oven...

Anyone had this fault? Anything I should try before calling JustAnswer?

 

[mainline]

IR check the heating element.

 

[James]

99% of the time it is the heating element.
spray oven cleaner kills them if you spray it into the fan outlet at the back of the oven.

 

[BlueVan]

Thanks both. I'll try to figure out how to remove the element. I have a friend who has a megger.

Thanks to your prompting I made another discovery: it's only the fan oven that trips the RCD, the microwave AND the grill work fine. So I'm guessing it was indeed oven cleaner sprayed in the fan opening (not by me) that did for that element. Maybe NEFF mention this in the manual but who has the time to read them.

I'm going to try taking the element out and cleaning it with isopropyl alcohol before replacing. If I don't burn our house down I'll report back on results.

 

[mainline]

Thanks both. I'll try to figure out how to remove the element. I have a friend who has a megger.

Thanks to your prompting I made another discovery: it's only the fan oven that trips the RCD, the microwave AND the grill work fine. So I'm guessing it was indeed oven cleaner sprayed in the fan opening (not by me) that did for that element. Maybe NEFF mention this in the manual but who has the time to read them.

I'm going to try taking the element out and cleaning it with isopropyl alcohol before replacing. If I don't burn our house down I'll report back on

Once there is a hole in the elements jacket it’s done for.

 

[Avo Mk8]

Maybe also check the fan motor before you take the element out! They tend to have exposed windings.
If motor and element have spade connectors, you could try disconnecting each in turn (both L and N) and see if it stops the tripping when briefly turning the fan oven on!

PS assuming it's a sheathed element of the usual type, I don't think cleaning it will make any difference, even if you just mean the terminations. Generally leakage develops inside, but you never know!

 

[BlueVan]

OK, so I'll take it apart over the weekend and have a look at the motor and fan oven element. The element is only about £25 so that's worth a punt...

 

[BlueVan]

Took the oven apart and checked the fan: not tripping the RCD. Cleaned the element around the connectors but still tripped the RCD. Took element out (2 screws and 2 nuts), checked it with a multimeter: 24kΩ sheath to terminal... No need to go to my mate with the megger.

Have ordered a new element - £43 inc. delivery. Will post again when it arrives and I fit it.

 

[BlueVan]

The element arrived. Very slightly different to the one I took out - it was missing a stud that goes into a hole in the back of the oven, however it still fitted securely. Oven now works perfectly with no tripping of the RCD. I knew my way around the oven this time so took about 30 minutes to do the swap. Very pleased. Thanks to all for the advice.

 

[mainline]

The element arrived. Very slightly different to the one I took out - it was missing a stud that goes into a hole in the back of the oven, however it still fitted securely. Oven now works perfectly with no tripping of the RCD. I knew my way around the oven this time so took about 30 minutes to do the swap. Very pleased. Thanks to all for the advice.

Glad you got it sorted.