Problem with Main Oven on SMEG D010PSS

[mark_r]

Hello,
I am hoping someone can offer some advice. I have a SMEG D010PSS double oven and the main oven will not heat on any setting, while the small oven appears to be working fine.

When trying to use the main over the selector switch appears to operate normally and the light indicating the oven setting comes on, however when setting the temperature the thermostat clicks as normal but the associated light does not illuminate and the oven does not heat up.

I reached for my multi-meter and followed some basic troubleshooting and checked the following

1) The oven thermostat – seams to be working fine – continuity when turned past relay click
2) The safety thermostat – again seams fine and has continuity. Also the main oven interior light is still coming on (and of course the fan comes on)
3) The main-fan thermostat seams to be running fine – fan comes on after ceramic thingy heats up.

So I assumed that the selector switch itself could be faulty and seeing as I could not find the “connections” for this online I though I would take a gamble and ordered one (from the UK Whitegoods shop of course). However on replacement the same issue persists 🙁

Surely it cannot be the elements – the main oven has 3 and not all can be blown. Also the oven is not tripping the circuit breaker and the top oven works fine.

I did notice a couple of strange things
1) If I disconnect the fan-element fan terminals and try and turn the oven on the same issue exists EXCEPT if I set the selector switch to the “defrost” setting and then the thermostat light will come on if I turn it up. But as I said on all other settings the thermostat light refuses to come on. I have no idea what (if any) elements the defrost setting affects.
2) If I leave the thermostat set at a heat beyond the click – when I rotate the selctor knob the thermostat light will flash on briefly when switching between the “top grill” and “bottom element” settings,

Any guidance would be greatly appreciated.

Mark

[timdowning]

Re: Problem with Main Oven on SMEG D010PSS

This sort of oven problem can be caused by the clock being in Auto setting. Or the clock itself not being set or faulty…

[mark_r]

Re: Problem with Main Oven on SMEG D010PSS

Hmm – yes I thought of that. However the oven does not function at all if the clock is not set (i.e. the selector switch does not work/illuminate) and when I set it I hear they relay “click” at the back of the clock and then the selector switch functions. I recall that if the timer is set for delayed cooking then I think there is only a single relay and this appears to be working 🙁

Thanks

Mark

[mark_r]

Re: Problem with Main Oven on SMEG D010PSS

OK so weird update. If I disconnect all of the connections to the top grill element (so both inner and outer element connections plus the earth), then turn the power back on, when the selector switch is in the grill position the thermostat light illuminates as it should to try and heat the grill. Clearly it can’t because there are no terminals connected but at least it appears to be trying. Once everything is connected back up it is back to the old behavior and no other setting works even when the top element is disconnected….

This is driving me nuts…

Mark

[electrofix]

Re: Problem with Main Oven on SMEG D010PSS

ignor the neon light in the situation you have they will light up on next to nothing

have you actually checked the fan oven element with the multimeter to rule it out. take a resistance reading after disconnecting 1 wire

if this oven has 3 elements in can be used in 2 modes. convection and fan. most people I meet don’t even know 2 modes exist so use 1 till it fails. what happens when you put it in convection mode

Dave

[mark_r]

Re: Problem with Main Oven on SMEG D010PSS

Hi Dave thanks for the reply. I did check the elements with my multimeter but I removed all connections before doing so. I seam to escalate that the bottom, fan and centre top elects all measured about 20-30 ohms resistance and the outside top element was about 60-70.. What is the idea behind leaving one of the terminals connected while I do the measure?

Also Imwill double check but neither the convection or traditional settings (non fan) appear to be working.

Mark

[electrofix]

Re: Problem with Main Oven on SMEG D010PSS

removing both connections does the same thing. removing one just makes sure you are reading the element and nothing else.

have you checked the power is coming through the clock. it looks from the pictures the clock has 2 relays to control ovens and it is possible for the main oven one to fail but the top oven one will still work

Dave

[mark_r]

Re: Problem with Main Oven on SMEG D010PSS

Dave, thanks again for your advice. I checked the rear of the timer and there is definitely only one relay and it appears to work as if it is “off” neither the selector switch nor the thermostat work.

That got me thinking though – there is another relay that I know cuts out the elements connected to the main oven door hinge. I think that it cuts out the elements when the door is open. I took off the side panel to reveal the switch, which has side terminals and four top terminals. A brown cable is connected to the rear side terminal (RST) and a white cable connected to the front side terminal (FST), On the top a brown cable is connected to the rear left terminal (RLT), two red cables connected to the right rear terminal (RRT), a white cable connected to the front left terminal (FLT) and nothing connected to the front right terminal (FRT).

I tested the switch with my multi-meter for connectivity and found the following

oven door open (switch in position 1)
RST is connected to RRT
FST is connected to FRT

oven door closed (switch in position 2)
RST is now connected to RLT
FST is still connected to FRT

Which is very weird as both white cables appear to be isolated in either door position. So I took a punt and figured maybe whne the door is closed FST should be connected to FLT (similar to the back connections) – so I pulled the white cable in FLT, connected it to FRT. Turned the power back on, expecting something to blow but the oven worked fine – the began heating, the thermostat light came on as normal and went off at the desired temperature.

So I am thinking it is this door switch that is the problem – my only concern is that what I have done may be masking a bigger problem. Does anyone know how this switch is supposed to work? It seams strange that the white cables would be connected to it – but totally isolated (in it’s current state) -but I am no expert.

This is the switch

And I have labelled the cable I moved as 1 and the terminal I moved it to as 2.

I think that the front connection should move in line with the rear one but not sure – does anyone know?

Regards

Mark

[electrofix]

Re: Problem with Main Oven on SMEG D010PSS

luckily with my mod powers I have got your image and modified it to explain

micro switches have a common terminal, a normally open terminal and a normally closed terminal

looking at your picture, I have added some arrows for clarity.It looks like there are 2 switches here and they will be electrically separate unless linked with wiring

when the switch is in the relaxed position ie the button on the switch is not pressed there will be an electrical connection between red and blue

when the button is depressed there is a connection between red and yellow

also see
https://www.youtube.com/watch?v=q6nP1FjxAMU

hope that makes things clearer

Dave

[mark_r]

Re: Problem with Main Oven on SMEG D010PSS

Dave,
first of all great job retrieving my image from a badly encoded post 🙂 Your diagram and video helps greatly and this is exactly what happens to the terminals at the rear – however with the front set of terminals Red remains permanently connected to Blue irrespective of the whether the micro switch is open or closed – so reckon that must be it. As you suggest it looks like this is two parallel switches in one unit.

New switch will be ordered this evening for UK Whitegoods and hopefully normal service will be resumed…..

Thanks once again fro the help and advice it is very much appreciated.

Regards

Mark

[mark_r]

Re: Problem with Main Oven on SMEG D010PSS

Hi,
just to complete the thread – I ordered a replacement door-hinge operated micro switch and replaced it this morning. Everything is working as it should now.

Appreciate all the assistance and can thoroughly recommend the spares service offered by UK Whitegoods.

Regards

Mark

[electrofix]

Re: Problem with Main Oven on SMEG D010PSS

thanks for update

glad to help

Dave

[Author]

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