[JamesJernigan]

Oven is over heating. This oven also gets very heavy daily use.
Dual fuel range with electric convection oven.
Oven has a large round temp dial gauge on the front. Also on the front are three LEDs indicating when the oven is on (blue LED), when the coils are in heat mode (blue LED), and clean mode (red LED).

Symptoms: Besides over heating to about 450 degrees, the temp gauge is sticking at 350, actual temp is 450. Also the heating LED does not light up even though the oven is increasing in temperature.

I replaced the oven sensor and the oven is still over heating. I have not checked the new sensor yet, but feel confident that it is operating properly as I do get accurate temp readings.

I checked all connections from the sensor to the control board as well as at the resistor (temp set dail), the temp gauge, and all connections on the control board.

IF it is the control board where the problem lies, can I replace a component, or do have to replace the whole thing?

[denman]

I cannot find any info on the given model number, please check it.

Usually the board must be replaced.
Manufacturer's do not publish board schematics so they are difficult to troubleshoot down to a component.

If one element is always on it could be that it's control relay's contacts are welded together.
But getting a replacement could be difficult as it is not available from appliance parts outlets. You have to try electronics supply houses like Digilab so you need the part's part number.
Also could be that the electronics is holding the relay closed all the time.
This would be non-repairable unless you are a pretty good electronics tech.

[JamesJernigan]

Thanks Denman - I think you are correct in that the relay is stuck in the on position. That could explain why the board is not sending the signal to the indicator light too.
The model # is correct. My local parts distributor (APD) also has trouble locating this model. If you go direct to thermador you can find it. I have the same isssue online at parts websites other than Thermador's.

Another quesstion - Wondering if this is connected to my currrent issue. A few months ago and previous to that about 6 months ago, the top heat element quit working. I tested it and it was still good. I reconnected it and it functioned properly. After the more recent second occurrance, I cleaned the contacts thinking that it could be getting oxydized. So far so good, but do you think that the increased resistance from the bad connnection has caused the relay to go bad? I have followed the leads from the elements to the board so i know exactly which relay switch it is. I have not checked for the relay part number yet if i can see it on the board.
I have ordered a new PC board, but it is going to take at least another week to get it. Would you recommend replacing the heat element as well? Do they slowly go bad? Don't want to cause same issue with new control board if things are starting at the coil.

[JamesJernigan]

Just thought I would give the link to the Thermador e-shop site with the correct oven parts info.

Thermador eShop Home

Thanks for your reply.

[denman]

Would you recommend replacing the heat element as well? Do they slowly go bad?
If it measures and looks OK it should be OK.
They do go bad by developing a hot but I think it fails fairly quyickly after this happens.