Hello: I’m sorry I wasn’t clear. Here is a link that describes troubleshooting on a modern electronic gas control: http://hometips.me/Mar/Icon-gas-control-valve-error-codes.pdfv It clearly has electronics in it that do much more than just give a temperature read out.
Here is a photo of controls. The lower three units are old style, electro-mechanical. Those are the ones I’d trust.