Intermittent electric oven heating

Myles45

Hi,

Does anybody know why an oven may be working intermittently?
We have a gourmets pride BL100 & recently it's decided that it will only heat up on random occasions. Sometimes it's fine & other times it will heat up to temperature & then just cool down with no warning. All lights are working ok & the thermostat seems to be ok as it switches on & off when it reaches temperature & cools, but only intermittently.
Not sure if it might be a loose or frayed wire as sometimes with a bit of bashing & banging it may start to work & other times it just won't work whatever we do, just have to leave it & try again another day. Very frustrating.
I was going to take the front panel off to have a look at the switches but not sure how it actually comes off. I've removed all the dials & knobs & the three screws along the bottom but it appears to be fixed solid still & I really don't want to have to pull the thing out & dismantle the whole thing if it's not necessary.

Thanks

Calahonda52

Out of curiosity I found this
http://www.ransomspares.co.uk/parts/brands/gourmets-pride/cookers-hobs/bl100/thermostat/144849.htm
so the moving parts piece of the stat should be accessible, don't know about the probe

These chaps are closer to home and I find them excellent
don't know if they do the piece u may need
https://www.spareparts.ie/shop/shop/Thermostats.16?layout=grid

Myles45

Thanks for that Calahonda52, I'm not certain it is the thermostat although it's certainly a possibility. Can they work intermittently?

I suspect it may be just a poor connection in the dial part which I could check if I could get the front panel off.

I think to replace the thermostat might require removing the whole hob top but not certain without more thorough inspection & pulling the whole oven out. I have done it before a good while back when I thought the elements were gone & had the back of it off but the elements turned out to be still ok, that may have been the start of the intermittent issue I think.

Calahonda52

re
Can they work intermittently?
yes.

I don't know how they work, I am guessing its the old bi-metal strip approach but I don't know if it is in the probe or the dial, my guess is in the dial and the knob widens or closes the gap that allows the current to flow to the element.

Myles45

I think I'm going to have to take the whole thing apart. It may just be dirt/dust on the potentiometer track, but I can't get at it to check without removing that front panel.

The Red Ace

the fan oven motor and element will have a common neutral directly from the terminal block, do a visual on that connection but it is more likely on the phase down from the stat, some cookers will have a safety device on this line usually clipped to the oven section, I would this suspect if fitted or it can be routed via a micro switch on the door which can also go faulty. best time to check it if you are a diy er is when it stops working then it makes it easier to trace

Myles45

Thanks Red Ace, I presume if the fan is still working (which it is) then it wouldn't be that common neutral terminal block. Also I'm pretty sure there is no micro switch on the door unless it's inside where the hinge is somewhere.

I'm fairly convinced its either the temperature selection dial or possibly the element selection dial, as messing with either of them with a gentle hand on one of the elements usually results in it eventually coming on, but it's hard to detect then if it switches off again without then just waiting to see if it continues to heat or not, which is the frustrating part.

Don't suppose you've had experience of this actual oven & know how that front panel removes?

The Red Ace

hi myles reading your response I am a bit baffled as normally a fan oven has one element but you mention elements, the simplest way to proceed is check that the oven stat has a live supply coming in with a phase tester, that will normally come via the timer, if you have no live there then the break is somewhere between the terminal block and stat. assuming all is ok as far as the stat what happens next when the oven stat is switched to desired temp the contacts on the stat for the fan close for the duration of the cooking period while the contact for the element open and close for the desired temp otherwise everything would be incenerated, if you don't feel confident working on a live supply get in a pro. otherwise good luck

Myles45

Hi Red, Yes it actually has 3 elements which you can choose between, depending on what sort of cooking you want to do. There's a round one on the back where the fan is, then one bottom & one on top which is split between grill in the centre & oven around the edge.
My biggest issue at the moment is finding out how to access the switches behind the front panel without taking the whole damn thing apart which I really don't have time for to be honest.

I only really get one day off a week being self employed & have even been working that too partly in recent months.

It doesn't worry me taking it apart, but I'd rather avoid it if there's a quicker way.

The Red Ace

ah ok, what you have is a multifunction oven, not familiar with the particular brand that I can remember so cant help you with accessing the switches but follow the fault finding procedure when you get it apart, the retaining screws if a range often run along the bottom edge of the control panel . I came across a brand new range cooker recently with a dodgy timer giving the exact same problem

Myles45

Yes, Sorry perhaps should have mentioned multifunction & yes there were 3 screws along the bottom which I removed after taking all the knobs off thinking it would then just pop off but it definitely still seems to be fixed solid which really doesn't make sense.

I'll give it a bash at the weekend & see where I can get with it & will revert back with results or more questions. Thanks for help so far though.

The Red Ace

it will probably have retaining screws hidden at the two ends under covers that have to be prised off, knobs will also have to be removed