Have a two year old in ground 25K pool / spa. Never had any issues with water or equipment but today the heater starter cycling on and off when trying to heat the spa. No strange temp readings and no error code on heater. It would just kick off and then the heating light would go from a steady orange to a flashing orange and back again - took 90 minutes to heat spa from 75 to a 100. Pool has great flow and filters are clean running at 17 psi. Never had any scaling issues in pool and CH is 300 right now. Any ideas?
2 year old Mastertemp 400 Cycling on / off for 30 second intervals
- Thread starter JoeMX82
- Start date
Take a look at the themal regulator. It's possibly all gunked up and not working properly.
Yes, what ps0303 said. It's more than likely the thermal regulator. On the newer MasterTemp you can access the regulator from the front of the heater (where the pipes are). There should be 3-4 3/8" screws holding the access panel to the cabinet. Once this is removed the regulator is behind the 4 notch round cap situated to the left of the water pipes and in-between the upper and lower pipe. Use a flat head screwdriver in the notches and unscrew counter clockwise. There's a decent spring behind the cap so watch out for that as it will be pushing as you unscrew and obviously turn the pump off before removal.