Pentair 400 SFS code

[Tonyjp]

My Pentair 400 has a SFS ( stack flue sensor ) code. I tested the SFS. It tested at 3.7 ohms which should be good. The heater is only 2 years old. The sensor looked perfect. When I hold down the two buttons to get the temperature it says 514 degrees. The unit is completely cold and will not start up. I have turned it off and restarted it. Same thing. Last time I left the breaker off for 3 days. When I turned it back on same code and 514 degrees. Because it is completely cold and will not reset I think it is the control panel. Has anyone else had this happen? Any suggestions?

 

[JamesW]

It tested at 3.7 ohms which should be good.

It should be 3.8 megaohms.

Show the meter during the test.