We have a Aquahot 431/12. Burner wouldn't fire. Performed pinpoint test and found both hi-temp thermostats open circuit. Replaced them only to have the same thing happen again.
I have now replaced all the thermostats, started boiling, shutoff but too late. Both high limits went bad again.
Did a component test on the controller which passed. Then I did ohm test on the C- plug on the controller side. C-1 and C-5 have continuity. Don't believe that is right.
Plus add off the market controller. Spheres SG 1553/ 12v.
Do I need Controller WPE-300-901? Or further testing?
I don't want to just keep throwing parts at it, but rather get to the root cause of this problem.
Thanks!