neff oven tripping when changing temp

[dalboy]

hi all
need a bit of help!

i have a neff oven that has been working fine for 3 years. top oven all works fine.

bottom oven I can choose from fan grill etc with the dial but as soon as I change temp from 0 within a few seconds it trips the rcd.

I bought a new bottom element and still same issue. don' think there is anything wrong with old one as multimeter shows continuity.

took thing apart and even swapped thermo from top oven with bottom and still trips so must be a bottom wiring issue?

there are 4 wires coming from the bottom thermostat dial. process of elimination I removed each wire and flicked power back on. it only seemed to trip when the red and white lead was connected - I followed this lead and it goes to where the bottom element goes into a small unit which I'm not sure what it is. on the image it is near the top with the red and white lead going into it. I put multi meter on this unit and it seems to have continuity.

I did notice behind this area above, the back plate is burnt / marked

all cables looked attached properly and none were frayed but some look black from the above

just to add I done all the tests without the bottom element attached. as it was tripping with or without it. assume if it was the element and I removed it, it shouldn't trip?

please see images attached if they help

thanks in advance really appreciate it!

 

[Mopasgas]

live and netural not connecting through switch at exctley the same time ,,,,,,,will cause rcd to trip ??? unbalanced load but with element diconnected its a wiring fault or that box ,try turning off and unplugging all other euipment on that circuit at fuse box

 

[dalboy]

so I wired the bottom thermostat dial to the top oven thermo cut out as I know top oven works. this didn't trip the electrics and i could turn heat up but as element isnt installed I can't verify it would heat but it didn't trip. only left it on for a few minutes to test.

I am going to swap the thermal cut out on top with one on back (as that's for bottom oven) and see if it doesn't trip and then heats with element fitted

does this sound reasonable?
the bottom oven wiring from thermostat must be ok if I ran it to top thermo cut out and didn' trip?

thanks

 

[assuhors]

The brown staining is just cooking fumes escaping and not unusual, does the main oven have a fan element as this would be the most likely culprit.
Do you have the Enr. number.

 

[dalboy]

The brown staining is just cooking fumes escaping and not unusual, does the main oven have a fan element as this would be the most likely culprit.
Do you have the Enr. number.

Thanks thats what i thought otherwise the fan etc at bottom wouldnt work.

yes i replaced main oven element and made no difference or do you mean another element? i can see an element at the top of the main oven which i presume is the grill. but even when i dont choose this on the selector dial, the electrics trip when i adjust the temp dial


the fan spins ok.

I believe model number is B1422N0GB/03


do you think it could be the thermo cut out like i mentioned a few posts up?

cheers

 

[assuhors]

Unlikely to be thermal cut out, you do have a fan element on that model it surrounds the fan blade and has electrical connections on the back.
Connect everything up apart from the fan element and see what happens. If no tripping then connect fan element and tripping will come back if it is the fan element.

 

[dalboy]

Unlikely to be thermal cut out, you do have a fan element on that model it surrounds the fan blade and has electrical connections on the back.
Connect everything up apart from the fan element and see what happens. If no tripping then connect fan element and tripping will come back if it is the fan element.

hmm interesting ok will take another look tonight if i can and see if i can find it.

why did it not trip though if i ran the thermostat to the other thermal cut out? or does the bottom thermal cut out connect to this other element you are suggesting.

thanks again.

edit: sorry which fan element would it be as the top one is what i swapped and still tripped.

https://www.espares.co.uk/search/pt1595/cooker-and-hob-elements?SearchTerm=b1422n0gb

 

[assuhors]

The fan element you will need if indeed it is that is Neff 00499003, there is a as good if not better quality element ELE9337 available on the Bay for £16.99
Don't use a cheap alternative as it will fail quickly.
The cut out on the lower oven prevents fan element overheating if oven fan fails.

 

[dalboy]

The fan element you will need if indeed it is that is Neff 00499003, there is a as good if not better quality element ELE9337 available on the Bay for £16.99
Don't use a cheap alternative as it will fail quickly.
The cut out on the lower oven prevents fan element overheating if oven fan fails.

thanks but this is what I already replaced originally.

I've even left the element out and disonnected and it still trips

 

[assuhors]

So you have changed the circular element?

 

[dalboy]

So you have changed the circular element?

yes you can access it from inside the oven and goes round the fan

I tried with no circular element attached and it still trips When changing temp dial

 

[assuhors]

Ok I would try disconnecting all three elements, top which is a dual element, fan and base elements if it still trips then you have got a very unusual fault.

 

[dalboy]

Ok I would try disconnecting all three elements, top which is a dual element, fan and base elements if it still trips then you have got a very unusual fault.

thanks will try

top oven works fine though so assumed the fault doesn' lay there but worth a try

 

[alan333]

A while ago I had random 'trips' with my Stoves range cooker. Obviously it's a completely different brand, but my problem was cured by insulating the un-insulated spade connecters - very similar to what your pics show.

Edit...here's the thread I created at the time if you fancy a browse...
https://www.diynot.com/diy/threads/cooker-circuit-occasionally-knocking-out-mcb.438910/

 

[dalboy]

right so still baffled with this

disconnected fan and element was already disconnected and still tripped.

changed thermal cut off and still tripped

changed thermostat from top oven and still tripped

a wire goes from bottom thermostat into thermal cut off. then another wire from thermal cut off has 2 spade connectors - 1 goes into bottom element which I have removed and the other part goes right into the bottom of the oven where a prong sticks out and is covered in insulation. is this just an earth?

when I remove this above lead from thermal cut out it doesn' trip.

maybe time to get a pro in....