sfs pentair 400k btu

Hello, I have a five year old Mastertemp 400 Pool/Spa heater setup that was getting E06 error (first error ever with heater). THEN: Replaced Sensor with aftermarket, and cleared the E06 code, but heater would shut off with SFS code on back of control board after 1-2 minute run. I ohm tested...

I've been scratching my head over this for a week now. I have 2 400k pool heaters for my pool. They both worked fine over the summer. Last year I had to replace the SFS sensor on one of them. The same one, a year later almost to the day, started acting up again. It starts heating, sometimes the...