I have a mastertemp 400 HD heater and I'm having an issue with maintaining the temp. Initially when you turn it on, it stays on and heats it up well. However once it reaches the set temp, it will shut off Rapidly instead of staying on for a few minutes to heat it back up to a degree or two over the set temp. It will turn on for about 20 seconds then shut back off, but overall maintains the set temp of the spa. In addition, the heater thermostat is a few degrees above the overall system thermostat. We replaced the thermostat on the spring inside the manifold as it was moderately corroded, as well as the bypass valve, although it wasn't broken. We also replaced the sensor on the exhaust as a rat bit some of the insulation off. Any idea as to what the issue could be? Thanks so much in advance!!!
MasterTemp 400 HD Shutting Off Rapidly
- Thread starter maxkittens2
- Start date
- Jul 21, 2013
- 65,367
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Pentair MasterTemp Heaters - Further Reading
www.troublefreepool.com
Have you tested or replaced the temperature sensor thermistor in the MasterTemp heater?
Temperature Sensors - Further Reading
www.troublefreepool.com
Thank you so much, I will check it out and replace itPentair MasterTemp Heaters - Further Reading
Have you tested or replaced the temperature sensor thermistor in the MasterTemp heater?
Temperature Sensors - Further Reading
)Pentair MasterTemp Heaters - Further Reading
Have you tested or replaced the temperature sensor thermistor in the MasterTemp heater?
Temperature Sensors - Further Reading
I just tested it and it’s measuring the correct number of ohm, a little over 15k ohms for 61 degree water. Any other ideas to check? Thank you
- Jul 21, 2013
- 65,367
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
You need to look at the diagnostic LEDs on the back of the board right after the heater shuts off rapidly.
Check the stack flue temperature as described in the wiki linked above.
Check the stack flue temperature as described in the wiki linked above.
Last edited:
Update it was the AGS sensor. Heater would completely shut off sometimes (lose all power) and randomly stop heating shortly after turning on. Hopefully someone else can benefit from this!