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Techdesk, Field Service Engineer
Category: UK Appliance
Satisfied Customers: 16407
Experience:  Whitegoods engineer working for a multibranded national company in the UK.
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Diplomat Range 850. The upper and lower ovens sometimes heat

Resolved Question:

Diplomat Range 850.
The upper and lower ovens sometimes heat when switched off. What causes this?
Submitted: 7 years ago.
Category: UK Appliance
Expert:  Techdesk replied 7 years ago.


Can you post the full model number of the appliance please?

Normally 3 letters and then some numbers.



Customer: replied 7 years ago.

Diplomat Range 850

ADP 5428 (Cream)

Model No. XXXXXXXXX /p>

Serial No. 30407714

Expert:  Techdesk replied 7 years ago.


There isn't an ADP5428 listed on the MFI techical disc, there is an ADP5426 which is cream 850mm dual fuel range cooker.


I've used the ADP5426 wiring diagram.


To have both oven heat up when switched off would require a fault on the controls for both ovens.

On the wiring diagram it shows two thermostats, one to control the top and one to control the bottom.

It would require both of these to be faulty to cause the problem you describe.

The cure would be to replace the thermostats.


The only other possible cause would be a wiring fault.

Have you had work carried out on the appliance just prior to noticing this fault?


When it goes wrong are the temperature lights lit?


Hope this is of some help.

Let me know how it goes or if you need more help.




Techdesk and other UK Appliance Specialists are ready to help you
Customer: replied 7 years ago.

Sorry, ADP5426 is correct.

I fitted a new element in the lower oven, recently. The fault with the lower oven occurred just after that. The fault with the upper oven followed a couple of weeks later.

When the faults occur, the lights are lit.

Expert:  Techdesk replied 7 years ago.


OK, from the description it would appear that both of your thermostats have the same fault.

It's very unlikely you got the wiring wrong on the fan element but it's worth checking.

You should have on one side black wire(s) and orange on the other. There may or may not be an earth wire in the centre tag.


Hope this helps