Pentair Minimax CH 150 natural gas pool heater will not turn on. I have jumped the TH/PP to the TH and the unit will run though. I have also jumped the high-limit, safety, pressure, and rocker switches with no changes. Since I cannot find any faults in the safety loop I am considering replacing the Electronic Thermostat (471677) but would like some advice first.

Hi,

Before replacing the t-stat...take the wires off at the t-stat and twist them together....heater should fire...if not then the t-stat is not the problem, it is in the wire...if it fires then replace the t-stat, but make sure that the t-stat you use will work with a "millivolt" system....

I think there is a good chance that your problem is the t-stat, but it will be best to make sure of it first.

heatman101

Sounds like a thermostat problem .Check the gas valve for voltage when it has reached the set temp if voltage is not present and valve still firing replace the gas valve .If voltage is present then the sensing bulb in the thermostat is bad /out of range.The thermostat needs to be replaced.It is possible that your thermostat is out of calibration or needs to be replaced. -------- This should help.Thanks.Helpmech.