Oven failure - advice wanted

Forums › Off topic › Oven failure - advice wanted

duckDecoy

899 posts

Ultimate Geek

Subscriber

#288613 12-Jul-2021 12:27

We have a 16 year old Westinghouse in wall oven. About 6 months ago the element around the fan stopped working, one night the oven just wouldn't get hot on fan bake. Google said most likelyl the element died so I ordered another and installed it myself. Worked fine.

On Friday night the oven was on and at 250'C when I heard quite a loud "whump!" noise from the kitchen. The oven had tripped the RCD/breaker switch. I turned it back on and the oven display came back on. I noticed that where the display is seemed to be very hot, but I don't actually know if thats normal. The fan element is now no longer working again. Possibly important: the breaker didn't trip the first time the element died.

Because I got the element so recently I am wondering if the element hasn't failed and if something else has gone wrong. I would prefer not to get a service person in because I am certain they will tell me thats its old and i should just replace it rather than paying them to fix it as something else might break soon, and charge me $180 for the visit. There's a few wonky buttons etc so I think that's good advice. But if it is just an element then that's a cheap $79 fix at a time when we've had few bills come in. Or maybe its something else small that people think I could fix myself.

My questions are:

1. Is it likely that an element would fail just 6 months after new? I believe it was a genuine part.

2. When an element goes does it make a loud "whump" sound? Or would this indicate its probably something else.

3. Is it possible for me to test if the element has failed? I don't own a multi-meter but i'd happily buy one if that was needed because I have borrowed on a couple of times lately. I wouldn't want to buy a replacement element only to have it not be the problem.

Ive been thinking about pulling the oven partially out at some stage because some of the buttons are "loose" and when you push them instead of it registering it instead pushes the display back, I sort of have to hold onto another button to stop it being pushed back when I want to push my intended button. I think it has come loose and it could just be a screw holding the display in place (suggested by google), and to access it you partially pull the oven out and take the "lid" off the oven and access the display and circuit board etc. So if anyone thinks that could reveal something useful too I could try that.

1 | 2

5816 posts

Uber Geek

ID Verified

#2743028 12-Jul-2021 12:50

We had an oven where a similar thing happened (Parmco oven, element around the fan stopped).

It wasn't actually the element though, it was the gubbins in behind the function selector. Basically a bad design where the switch got hot and shorted out. Parmco fixed it twice (first under warranty, the next because I bleated CGA).

We replaced the oven the third time it did it.

Yours could be similar, or it could just be the element, though there isn't much that can go wrong with an element - they're just a big resistor.

Fred99

13684 posts

Uber Geek

#2743043 12-Jul-2021 13:28

On Friday night the oven was on and at 250'C

What were you trying to cremate?

Sure you can test the element with a multimeter, should be about / less than 50 ohms, then test to see if its shorted between either or both terminals and the metal tube of the element.

There is a certain randomness to element failures, but 6 months doesn't seem very long. Are you sure that when you replaced the element the cables weren't accidentally touching something that gets hot? If that was the case and insulation on the wire failed, then you'd get a bit of a whoomph and breaker / RCD would trip.

duckDecoy

899 posts

Ultimate Geek

Subscriber

#2743047 12-Jul-2021 13:36

Fred99:

On Friday night the oven was on and at 250'C

What were you trying to cremate?

Heh. Was reseasoning my cast iron pan

robjg63

4099 posts

Uber Geek

Subscriber

#2743145 12-Jul-2021 14:06

I was also wondering why you had it at 250 - that's pretty much maxxed out!

Elements popping can certainly make a noise.

If the element burns out cleanly it *shouldn't* pop the circuit breaker. If something grounds - that could - possibly the element breaking then touching the body of the oven? You would think in that case it should trip the circuit every time you switch it back on though...

Nothing is impossible for the man who doesn't have to do it himself - A. H. Weiler

sleemanj

1490 posts

Uber Geek

#2743149 12-Jul-2021 14:12

Element could have warped with the heat and contacted the chassis causing a short to ground maybe.

Potentially there is a fuse, or thermal fuse as well in the oven that might have blown at the same time as the circuit breaker tripped so element might test out ok but not work still.

---
James Sleeman
I sell lots of stuff for electronic enthusiasts...

Fred99

13684 posts

Uber Geek

#2743161 12-Jul-2021 14:32

sleemanj:

Element could have warped with the heat and contacted the chassis causing a short to ground maybe.

Potentially there is a fuse, or thermal fuse as well in the oven that might have blown at the same time as the circuit breaker tripped so element might test out ok but not work still.

This image shows how the elements are constructed:

Sure the elements usually blow and open circuit if part of the heating wire overheats and that happens with little fuss, but if the wire gets too close to earthed sheath, it'll arc and blow a hole through the side.

That outer sheath is earthed - should never be possible for it to be live.

They're (Ovens) not normally wired in with an RCD as there's always some leakage to earth through the MgO insulation, and they'll trip RCDs. And they're usually on a high current breaker (or fuse) - so if that happens then they can go with quite a pop before the breaker trips.

(the person who created and uploaded the image to Wiki needs a spell checker)

duckDecoy

899 posts

Ultimate Geek

Subscriber

#2743170 12-Jul-2021 15:10

Dammit, its sounding less like this is something I can easily self diagnose with certainty.

Another question - would anyone recommend NOT using the oven given the fan element isn't working and something popped the circuit breaker. We have 2 other elements that still seem to work and we could potentially limp on like this for a while.

Sharesies

Trade NZ and US shares and funds with Sharesies (affiliate link).

MadEngineer

4295 posts

Uber Geek

Trusted

#2743197 12-Jul-2021 15:47

If you have to ask then it’s a no. I don’t recommend you use that oven at all until you’ve had it repaired.

It used to be that when you blew your oven fuse you’d have to call a sparky to replace the fuse wire as the old fuse cards you got didn’t have wire of a suitable grade to rewire yourself nor would anyone sell you said fuse wire.

You're not on Atlantis anymore, Duncan Idaho.

Fred99

13684 posts

Uber Geek

#2743206 12-Jul-2021 16:14

I'm amazed at how many flats I've visited that still have ~40 year old Shacklock ranges in them, still in serviceable condition.

Our European made gourmet oven has caused me endless grief over 10 years. Poor design mainly - door hinges, electronics exposed to oven fumes, and poor service from the NZ agent/importer.

gregmcc

2147 posts

Uber Geek

ID Verified

Trusted

Lifetime subscriber

#2743277 12-Jul-2021 17:28

it's unusual for the oven to trip the RCD as typically hot water and ovens are the 2 items that are not on an RCD.

Anyway RCD tripped is a earth fault, most likely one of the elements has shorted internally to the metal sheath of the element, some times they blow a hole in the side of the element so a close visual inspection would show it.

Failing that you need electrical test gear to figure out which element, something the average homeowner isn't going to have.

The choice here is to do a cost assessment on repair vs replace and go from there

SATTV

1648 posts

Uber Geek

ID Verified

#2743281 12-Jul-2021 17:50

gregmcc:

it's unusual for the oven to trip the RCD as typically hot water and ovens are the 2 items that are not on an RCD.

Anyway RCD tripped is a earth fault, most likely one of the elements has shorted internally to the metal sheath of the element, some times they blow a hole in the side of the element so a close visual inspection would show it.

Failing that you need electrical test gear to figure out which element, something the average homeowner isn't going to have.

The choice here is to do a cost assessment on repair vs replace and go from there

A wall oven is not always hard wired, often they are plugged into a standard 10A wall socket so will be on a RCD.

The OP may be confusing RCD with MCB.

I suspect it is just the element gone but without seeing it and testing properly it is hard to make that call.

John

I know enough to be dangerous

Bung

6496 posts

Uber Geek

Subscriber

#2743282 12-Jul-2021 17:51

Fred99:
I'm amazed at how many flats I've visited that still have ~40 year old Shacklock ranges in them, still in serviceable condition.

Until something needs changing then the spade connectors on the old wiring start falling off when you touch them.

That could be the OP's problem, the hot wire on the element dropped off and shorting.

Scott3

3973 posts

Uber Geek

Lifetime subscriber

#2743292 12-Jul-2021 18:20

SATTV:

A wall oven is not always hard wired, often they are plugged into a standard 10A wall socket so will be on a RCD.

The OP may be confusing RCD with MCB.

I suspect it is just the element gone but without seeing it and testing properly it is hard to make that call.

John

Typically wall ovens need around 16A.

Sounds like this is a freestanding range with oven and hobs (and perhaps power outlet's mounted on it). I think typically these need around a 32A feed, but are often on a special oven plug and socket.

Not sure what the rules are, but would seem prudent to have it protected via an RCD especially if a oven with mounted power sockets could be installed.

MadEngineer

4295 posts

Uber Geek

Trusted

#2743356 12-Jul-2021 19:23

FWIW, we had our kitchen renovated and while we do need a new switchboard and re-wire, the kitchen itself was re-wired with the outlets (microwave, fridge, dishwasher and wall socket) RCD protected but not the oven. The oven is on its own 32 amp circuit with a proper oven socket on the wall, a 32 amp switch and the original 32 amp fuse (asbestos liner included!) in the switchboard. Oven does have its own outlets.

You're not on Atlantis anymore, Duncan Idaho.

Fred99

13684 posts

Uber Geek

#2743411 12-Jul-2021 19:35

Scott3:

Not sure what the rules are, but would seem prudent to have it protected via an RCD especially if a oven with mounted power sockets could be installed.

I don't think they've been available / legal on new appliances in NZ for decades.

And nope - an RCD on an oven circuit could nuisance tripping, even if it's a wall oven it has to be on a separate circuit minimum 15A, so not plugged in to a 10A socket.

(not a sparky - part time slave to one one who's away ATM).

1 | 2