2story

Hello! I am new here I have a 04 Prodigy Serial H3E1485 Temp is set on 80, temp of water in the tub is 95, I am a HVAC tech-which means I know nothing about hot tubs but would ASSUME that I have a dirty or bad thermistor, I see on the board that I have a Hi limit, next to it a thermal reg jack, one is on the inlet and the other on the outlet of the heater, do they screw in to the heater ? Is this my problem?? It is not a big issue except in the summer when i would like to let it cool off, with minimal use. Is cleaning it something I should bother with? Drain the tub to replace or wet??