Oven Simmerstat Questions, Help needed.

[peps1]

Hello Guys,

I got a Magnetic Stirrer Hotplate from ebay with a broken temperature control going so cheap I thought it would be worth a punt.



Got it on the bench today and tested it out, as described, everything works apart from the temperature control, the plate heats up but cant be adjusted, and the control pot just keep turning and turning. 

I stripped it down, and assume the problem is the Simmerstat (something I have never worked with before).

The Part is a Diamond H Controls LTD 31ER1TF 45, with tabs for Line, Load A, Neut, and Pilot, Load B (not connected)




I googled he part number and found a this:
http://www.amazon.co.uk/UNIVERSAL-REGULATOR-SIMMERSTAT-COOKERS-APPLICATIONS/dp/B00J5JOX64

That states it replaces Diamond H 31ER1TF

Should I order this one, or am I missing something important here?

[Gyro]

So long as the physical dimensions are ok (shown in answer to a customer question) then I think you should be fine.

There's nothing particularly complex about a Simmerstat, it's a simple thermo-mechanical device. Inside there's a heating element wrapped round a bi-metal strip to simulate what the main element is doing. The strip opens the switching contact as it is heated, breaking the circuit and closing again as it cools. The knob simply changes the position of the 'fixed' contact so that more or less heating of the is needed to open the contacts again. Think of it as a very slow mechanical pwm. If the knob just keeps turning then it sounds like a mechanical failure, or possibly failed internal heater.

As long as you can identify and map the connections across to the new simmerstat correctly then you shouldn't have any problem.

[peps1]

Thank so much Gyro.

Very good of you to take the time to explain a simmerstat 

[Gyro]

My Pleasure