Recent content by jstanley993

  1. J

    Mastertemp 400 Temperature Issue

    I have a Pentair Mastertemp 400 that is about 3 years old. Recently the spa has not been heating like usual. The spa will only heat to 91 degrees. I checked the temperature setting on the heater and it set to 104. After reading on the forums I believed the culprit could be the thermistor. I...