Error code 21 on Thermador

I replaced the board 2 years ago and fixed the problem but now have an error code of 21 - is this the board again? The range is connected to a surge protector - do I need a better one or is this just an unfortunate common problem.

Hello,
The 2-1 error is a Potentiometer Failure. The potentiometer it’s referencing is the temperature selector. It could be that that part is bad, or you have a bad wire or connection between it and the X3 plug on the relay board.

KC
profaultcodes.pdf (142.2 KB)

[quote=Servicer;289271]Hello,
The 2-1 error is a Potentiometer Failure. The potentiometer it’s referencing is the temperature selector. It could be that that part is bad, or you have a bad wire or connection between it and the X3 plug on the relay board.

KC[/quote]

Any suggestions on how to check this - determine which part is bad?

You’ll have to measure the resistance of the potentiometer, either at the part itself or at the X3 connection on the board.

At the potentiometer, if you measure across the pins that the white and red wire connect to, you’ll read around 20.5k ohms when set to 350. If you measure from the x3 connection, you’ll disconnect the harness and measure directly across the wires.

[quote=Servicer;289405]You’ll have to measure the resistance of the potentiometer, either at the part itself or at the X3 connection on the board.

At the potentiometer, if you measure across the pins that the white and red wire connect to, you’ll read around 20.5k ohms when set to 350. If you measure from the x3 connection, you’ll disconnect the harness and measure directly across the wires.[/quote]

Any description (location, how to get to it, etc) or diagram of potentiometer before I pull the range out this weekend and test it? Also, if it’s is the actual part/potentiometer, do you know the part number?

To get to the back of the potentiometer, you’ll need to remove the part of the cooktop that sits behind it, i.e. the burners, griddle or grill.

Attached are some pages from the service manual that pertain to the potentiometer.

The part number is 418329.
KC
2_1_Error.pdf (513.5 KB)