Combi Oven tripping MCB....when fan assited oven has run for 15 to 20 mins!!??

[Tonewheelkev]

Hoping to get some ideas on why a 13 month old Hotpoint Combi oven (Yes....guaranteed for 12 full months...HaHa) might be tripping the MCB at the box.
This doesn't appear to happen when Microwave is selected.....but only seem to happen when Fan assisted oven has been running for 15 to 20 mins.

 

[telectrix]

is it tripping MCB or RCD? if it's MCB, what ratting is the MCB and what kW rating is the oven?

 

[Tonewheelkev]

It's a Wylex NHSXBS1B32 (32A 30mA SP Type B RCBO) that is tripping the ring circuit.
The combi-oven is rated at 2000w on the back panel

 

[Mike Johnson]

Are you saying your oven is on a ring circuit?

 

[Tonewheelkev]

Are you saying your oven is on a ring circuit?

Hotpoint Supreme Chef Combi/Microwave....yes....3-pin plug...designed that way....doesn't require dedicated wiring (according to specs!!)
Has worked fine for just over 1 year....now out of guarantee

 

[Mike Johnson]

If it's only just out of guarantee may be worth a call to the manufacturer to see if they will do anything, but meanwhile, have you recently bought any new or moved any old electrical appliance's and plugged them into the same ring.

 

[telectrix]

combi ovens in leeds??? whatever next, inside bogs and baths not hanging on a nail on the kitchen door?

 

[Mike Johnson]

Oh come on you know he was posh, he's got electricity.

 

[Tonewheelkev]

If it's only just out of guarantee may be worth a call to the manufacturer to see if they will do anything, but meanwhile, have you recently bought any new or moved any old electrical appliance's and plugged them into the same ring.

Trying to contact Hotpoint....now Whirlpool...is a complete joke....chat was terminated...all I can do is book a service.
No....no new/old appliances in the mix. Have tried plugging combi into different socket.....behaves same way, tripping the MCB after around 20 mins of fan assisted oven functioning. (Microwave function doesn't trip out.....then again, microwave only on for shorter time!)
Am as sure...as I can be ( )....that the oven is the culprit.

 

[Mike Johnson]

The problem with plugging into a different socket, it could be the same ring, try turning off the offending MCB and then find another socket that is still working and plug the oven into that, if that establishes the problem is the oven, then its time to call a technician I'm afraid.

 

[Tonewheelkev]

Believe it or not.....the flat I'm in has only one ring....all sockets on same circuit!
No probs for 25 years with this......

 

[Mike Johnson]

Book a service, at least you will get a guarantee for the repair. Unless it's the MCB, but doubtful if it's only when using the oven.

 

[marconi]

Could you try your oven at a friend's or relatives home please?

Do you regularly clean the oven iaw the manual - see 'auto clean' page 27 of 33?

https://manuall.co.uk/hotpoint-mwh-338-sx-microwave/

Have you had a cooking incident recently which may have contaminated the fan or the grill element?

HAve you tried operating the oven as the only item plugged into the ring circuit - ie every other socket on the ring does not have a plug in it - this last bit is important?

 

[Tonewheelkev]

Could you try your oven at a friend's or relatives home please?

Do you regularly clean the oven iaw the manual - see 'auto clean' page 27 of 33?

https://manuall.co.uk/hotpoint-mwh-338-sx-microwave/

Have you had a cooking incident recently which may have contaminated the fan or the grill element?

HAve you tried operating the oven as the only item plugged into the ring circuit - ie every other socket on the ring does not have a plug in it - this last bit is important?

We appear to be on a similar wavelength here!
Funnily enough....my next move was to take the unit to another dwelling....to see if I can replicate the trip.
It also occurred that I might borrow a 2kw bar heater...and see if that also brings along the trip.
Perhaps...there's a problem with the Wylex breaker!!
As it happened....ran autoclean yesterday FWIW......can't find any info 'out there' ....on how important (or otherwise!) it is to run this.
Had the unit apart today.....it's soooo clean really....can confirm no cooking incidents.
If the unit does work 'elsewhere' without problems...I'll look into having the breaker tested/exchanged
Sounds like a plan!!

 

[marconi]

Sounds like you have a good reason to order a take-away tonight.

For us it is Welsh leek and potato soup which includes bacon :

http://www.travelaboutbritain.com/recipes/leek_and_potato_soup.php

 

[marconi]

It would be very helpful to know how the ring circuit at your friend/relative's is supplied ie: RCBO, MCB, MCB and 'up front' RCD or a fuse. If it is easier take a photo and post it.

Also when you do the everything unplugged test I should have asked you to turn off all switched fused units which look like these and may also be fed off the ring:

https://www.tlc-direct.co.uk/Produc...nqwRxNmRuh7n7RMb9Ym4WGQBjxfaInNxoCJaYQAvD_BwE

 

[Sparkingmad]

Is the element in the oven loose? Has it moved backwards? Stoves used to have an issue where due to bad design the oven element could slide back when element heated up it would expand and cause the connections on the back to short on the back casing. Also they had aluminium foil on the insulation on the back of the oven. This one had me going for ages, stripped the damn apart and tested all fine put back together shorted out. In the end I had insulation resistance test the damn thing after every screw was put in. Finally found that the foil was deflecting and touching a neutral connection on the back. Good luck.

 

[Sparkingmad]

We appear to be on a similar wavelength here!
Funnily enough....my next move was to take the unit to another dwelling....to see if I can replicate the trip.
It also occurred that I might borrow a 2kw bar heater...and see if that also brings along the trip.
Perhaps...there's a problem with the Wylex breaker!!
As it happened....ran autoclean yesterday FWIW......can't find any info 'out there' ....on how important (or otherwise!) it is to run this.
Had the unit apart today.....it's soooo clean really....can confirm no cooking incidents.
If the unit does work 'elsewhere' without problems...I'll look into having the breaker tested/exchanged
Sounds like a plan!!

How did you get on?

 

[Mike Johnson]

I saw an interesting video on u-tube on this subject, seems the oven heating element had a split in it and it took about twenty mins for the trip to happen due to expansion of the casing.