Naff Neff Double Oven!

[puffernutter]

Our Neff double oven trips the RCBO whenever anything is turned on for the fan oven. The smaller oven/grill (non fan) is fine and what we're having to use for the New Year's Day roast!

When you turn the main switch on, you then need to set the clock. The cooker is fine at that point, the moment you move the fan oven switch it trips. I have turned the oven on with the fan oven switch in any of its 8 or so positions (including just the light - and I have removed the lamps, so it isn't them!) it will trip the RCBO.

Anybody come across this?

Leaving it alone today, but plan to investigate over the weekend!

Cheers

Peter

 

[gaz1]

is it a new fit or old fit

did it work before and had no trouble

 

[ajlelectronics]

It just needs a new heater element. Not expensive, just as well as we used to go through them every 6-12 months for some reason in a Whirlpool oven. We now have a Neff and so far it has been fine. Just the very strange quirk that you get no handles with the grill pan. Never worked out how they expect it to be used.

 

[Johnnybravo]

^^
What he said
Ours did exactly the same,new element even though the old one still worked, and problem solved.

 

[Bullet2012]

Neff definitely read Naff as the OP says.
We had a new Neff single oven installed a couple of months ago. It replaced our 20 year old falling apart Creda.
It is complete pants, looks fantastic but I would not describe is as user friendly, also it takes an age to change temperature. Has way to many functions, it tries to do the job of a twin oven as well but it cannot even function correctly as a single.
I will be looking for a replacement in the January sales, and it will not be a Naff

 

[Wendelspanswick]

Might be worth substituting the RCBO as well, a friend spent months trying to resolve a fault he thought was in his wiring or cooker, I came round with my tester and the RCBO failed straight away.

 

[puffernutter]

All, sorry, been cooking all afternoon! (The Mrs is on the cusp of a relapse of labyrinthinitus and I'm taking as much load as I can).

The oven was secondhand about 3 years ago. It has worked without issue since I installed it.

It did it first (trip the RCBO) about a week ago, then the problem went away.

After I'd finished cooking today I showed my eldest son the fault, except the fan over just turned on without any issues!

The RCBO is less than 6 months old as after I had an RCD melt in the fuse box on a different circuit, I replaced the lot!

So, could it be condensation or expansion creating a gap between earth and live or neutral?

Cheers

Peter

 

[puffernutter]

And it is still going without any problems - no idea what caused it - have to wait for it to happen again!!

Cheers

Peter

 

[hotponyshoes]

It will be one of the elements on the way out.
They are a coil of resistance wire wrapped over a guide rail and inside a tube.

As the wrapped bit fails it goes sort of fuzzy (like it oxodises) and touches the outside of the containing tube. The oxide has some resistance but can basically short to earth and trip the rcbo. Sometimes it will burn itself off on the first contact so it might trip once and then be ok again for a while.

Some of them have multiple windings in each element so one can blow out and it will carry on working after a few trips although it might be taking longer to warm up than it did before.

I use a couple of ovens for some mobile catering, they are all on wheels and just pushing them around when on will trip a decent rcbo. I think the elements are prone to breaking if moved around when hot as I replaced a few fairly often before I worked out that leaving them to cool down before moving helped a lot!

 

[winchman]

Usually just an element going to earth easy to test with a merger if you have access to one, possibly the fan but they just usually seize, just replaced my fan before Christmas £30, Had to buy a new fridge today! Even a tight wad like me couldn't fix it.

 

[puffernutter]

An update. It has been very fickle, choosing to trip the RCD when my wife wants to do baking on a Saturday morning, but fine when I want to grill burgers or sausages in the evening!

However, I ordered a new element and last Saturday, when it started tripping, I decided enough was enough!

I removed it from the housing and got into the back. Before doing much else, I removed the all leads from the circular (fan oven) element (left them dangling in the air) and turned the power back on. It tripped. This means it wasn't the element causing it! So, on the plus side, I have a spare element

Looking in the back, there is a fair amount of insulating material. Above the top over element. which has 4 spades in a row, there is obviously an air leak from the oven and the insulating material (which frays) is contaminated with grease and in the area of the spade connectors. My supposition is (and I don't have a wiring diagram) is that when first turned on, the oven is actually "dead" until you set the digital clock. When that is set power is available to the control switch and any movement gives either a N-E fault or a L-E fault. Anyway, I trimmed that insulation material back and it turned on without tripping the RCD (could just be luck).

We'll have to see what happens over the next few days/weeks....

Cheers

Peter

 

[puffernutter]

And the bloody thing tripped the RCD tonight!

I need to get a circuit diagram so I can fault find properly!

Peter

 

[Olderisbetter]

On a whirlpool we have it tripped at random times, It turned out to be the main temperature stat on the oven, It was somehow down to earth randomly, Found a spare from a scrap oven and it has been fine since.

 

[puffernutter]

Credit to Neff (with a disclaimer!) I now have a circuit diagram.

The clock (when set) engages a double pole relay (switches both N and L). So, when I set it to Fan Oven with the element removed and the wires dangling in the air, set the clock and it still trips, than indicates a N-E fault somewhere....