AEG Competance 5151 B W

[Iain Muir]

The oven is working fine but it takes a full 15 minutes (timed, not estimated) to get the empty oven up to 180⁰C. Why might this be? I think it only has one element (though I may be wrong) so I would expect it to heat up normally or not at all. Can an element partially fail? Thanks.

[electrofix]

look on the label inside the door and post the compete prod number should be 11 digits 9 plus 2 extra

Dave

[Iain Muir]

Thanks Dave. There’s nothing quite in that format but what there is is:
Model Code: PNC 944 181 059
S-No: 83641817
Type: 56 BJB 39 GA

[electrofix]

this oven is bascally a conventional oven that is fan assisted. A true fan oven has a circular element around the fan
you oven relies on 2 elements. The grill element and another one below the floor that you cant see. Its not unusual for the bottom one to fail then it takes ages to heat up as the remaining element struggles to produce enough heat

built around 1996, not a bad age, not much today would last that long

you need to do some checking to confirm this is the fault

lower element seems to be available
https://shop.ukwhitegoods.co.uk/8996…r-oven-element

Dave

[Iain Muir]

Thanks Dave, that certainly sounds like what the problem is!

Iain

[Iain Muir]

I’ve removed and tested the element – it’s a double element unit. There’s no sign of physical damage and there’s continuity in each element though quite widely differing resistance. One element, marked 500W at 230V has a resistance of around 100 ohm, which adds up, the other which is marked 600W at 86V (rather surprisingly) has a resistance of around 13 ohms, which again is about right.
So, it looks like that double element is OK. The grill element works fine – as a grill at least.
Any other ideas about slow heating? Thanks.

[electrofix]

well it could be the switch behind the knob. the lower element may not be energised

try turning it on and see how quick the floor of the oven gets hot. It will get warm by reflective heat from the grill element but it should get really hot

Dave

[Iain Muir]

Thanks for your help. The oven floor is heating up, but whether it’s one or both elements I can’t tell. Why are there 2 elements, and one rated at 86V, anyway?

[electrofix]

think they use the other one in series with the grill element to stop it grilling everything so now the check is
does the grill element get hot in oven mode. we know it works in grill mode

Dave

[Iain Muir]

Yes, Dave, the grill warms up in fan oven mode too.
The oven has a multitude of functions: fan, convection, grill, grill with fan and one I’m not sure about! (the symbol is an asterisk with a water-drop below it). I suppose the double element is to enable that wide range to be provided, though in what combination I can’t guess. Perhaps only one of the floor elements is being energised instead of both when set for fan/convection oven. That’s something I could test if I knew that both elements should be energised.

[electrofix]

are you checking the top element in the grill / fan setting or the oven setting as they are wired differently

fan.grill is grill element on full power plus a fan. oven setting uses one of the lower elements to lower the grill element output so it does not grill the food

the water drop symbol will probably be fan only with no heat which can be used to defrost food

Dave

[Iain Muir]

I checked it in oven mode – so top and at least one bottom element working OK. I guess the 86V element will be the one in series with the grill when in oven mode to reduce grill heat (reflecting voltage drop caused by grill element), and that the 230V lower element will also be energised in oven mode. So in oven mode, both lower elements should be energised…

[electrofix]

yes but one will be fed with 240v the other because its in series will have a lower voltage

but if both elements are working in oven mode there is no reason why its taking that long to heat up. the only long shot and it does not happen often is there is a break in one of the element that opens when it gets hot

Dave

[Iain Muir]

OK. I’ll get round to testing it sometime in the next few days. If one isn’t being energised, and no obvious fixable reason for it, I guess a new ‘mode selector’ (or whatever it may be called) will be needed, if available. Thanks again for your help.

[electrofix]

sounds like a plan

Dave

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