When I turn on my spa which I use a Pentair Master Temp 400 it does not turn on right away, first shows ADO on the screen of the heater, then SFE then turns on finally. Temperature always starts at 60 at 70 degreases I increase it to 102 degrees it will then proceed to to 102 shut off and never come on again until I increase it again to 102 and the same thing happens again. Please help?