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Tyler Z.
Tyler Z., Appliance Doc
Category: Appliance
Satisfied Customers: 80244
Experience:  9+ years being an appliance technician with factory training.
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I have a Thermador SMW272B Oven/Microwave. During prewarm

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I have a Thermador SMW272B Oven/Microwave. During prewarm to 425 Degrees, the oven went to about 365 degrees and stopped heating. I also tried to use the broiler and the convection heating control and all are inop. The panel lights are normal, and the fan comes on. The self cleaning feature was not used recently. I confirmed that the 40 Amp breaker in the house electrical panel is not tripped. Previous postings seem to point to the possibility of needing to hit the Reset switch on the Electronic control panel, or a problem with the Hi Limit Switch on the Relay/Power Board. Please advise
Hello, and thank you for using this service. I'll be helping you with your problem today.

There is a high limit switch located behind the door latch assembly. Just open the door and remove the vent that goes across the door latch assembly to access the switch. Push the tiny red button to see if it will reset. If not, then you need to replace the relay control board (if the unit is getting 240 volts) which is located under the top panel of the oven, meaning you'll need to uninstall the oven and remove the top panel to replace it.
Customer: replied 6 years ago.
I removed the vent that goes across the door latch assembly, but I am not sure about the location of the switch. I did not see a tiny red button. Can you describe its location with the metal enclosure just behind the door latch. Is in on the right or left side within the metal enclosure?
you remove the metal enclosure, it's behind it just behind the latch assembly. The switch looks like a 1" black and silver device with a tiny red button on it.
Customer: replied 6 years ago.


I will check when I get home from work. Just to be sure, the 6"x6" metal enclosure has to be removed, and the 1" black and silver device is on the back side of the metal enclosure? Would it help if I sent a digital photo or can your receive attachments?

yes that is correct. And that's up to you, but it shouldn't be that difficult to find. If you need to send a picture, use the insert/edit image button.
Customer: replied 6 years ago.
I cannot seem to insert a picture in this text box with my MacBook Pro. At any rate I see a black and silver round device that must be the Hi Temp Switch. I cannot see any red button sticking up beyond the top of the device, which probably means the switch did not pop up. Please confirm
there is definitely a tiny button on the top of the black part smack dab in the middle. Just push on it's (it's a tiny square red switch) and if it clicks it will reset, if not replace the control board.
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Customer: replied 6 years ago.
I accepted your answer for payment. I have found out that the control panel is no longer serviced by appliance dealers, and I have to send it for repair to Core Centric Solutions . They will rebuild the display and power relay board, part number 492067, $179.98. How can I remove this part to send it in? I know that the facing around the microwave pops out, and there are two screws holding the top electronic face. Is the control board located in the metal enclosure behind this facing?
yes the control board is located behind the facing, but to access th relay control board you'll need to pull the oven forward out of the cabinet and remove the top panel to access that board.
Customer: replied 6 years ago.
You have been very helpful but I am still having problems. An appliance repairman who works with Thermador was supposed to come out and pull the relay control board but never showed and now we are close to Christmas. I have a Thermador parts list with diagrams for the SMW272B (the components top to bottom are oven Display board, microwave, warming drawer, and oven). The top plenium control parts show a part number 16-10-660 Main power/relay PCB Conv, but the Concentrics Solution parts order list shows a Part 492067 Single oven control kit (Display and Power Relay Board for $179.98. You mail it to them and they rebuild it. Not sure if the two parts are the same.

I did not understand you response about having to pull the oven forward. It is far removed from the top plenium. Looks like you just remove the cover around the microwave, then remove two screws on the display face, and the top display drops out, exposing the metal box surrounding the relay control board. Can you describe the appearance of the relay control board?
The relay control board is a rectangular board behind the display board and it's about 5" wide and about 8" long.
Customer: replied 6 years ago.

. Thanks. I see the Relay control board. I am going to call CoreCentrics one more time since the repair kit says it is for Display and Power Relay Board. Does this mean two boards have to sent in? I assume the display board is the one attached to the back of the display screen.

yes both boards need to be sent in. And the display board is part of the display screen.
good luck.

Edited by appliance Doc on 12/15/2010 at 1:55 PM EST
Customer: replied 6 years ago.
Your advice did not turn out to be accurate. I was able to get a technician to troubleshoot the oven. The problem was a fired Display circuit board, and a hole in the oven heating element. He replaced both and the oven is now fixed.

that is actually what I said as well. I stated that your control board was shorted, but aparently the element was bad as well.