Pentair Mastertemp 300 shows 1 degree for pool temp. Heater continously runs. I have replaced the thermistor with no change.
MasterTemp 300 heater always reads 1 degree for temperature.
- Thread starter dogcomputer
- Start date
- Jul 21, 2013
- 65,496
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Connect a 10K resistor in place of the temperature thermistor.
If you still show the problem it is the wiring harness or board.
Have you checked the wires for signs of rodents chewing on them?
If you still show the problem it is the wiring harness or board.
Have you checked the wires for signs of rodents chewing on them?
No sign of wires being chewed, control board was replaced 4 years ago. I don't have a resistor, is there another way to test the board.
You can get a resistor.
Do you have a temperature sensor in your system?
If yes, you can connect to that to see what the temperature reads.
Note: Do not operate the heater with the water temperature sensor bypassed.
Just do it as a test to see if the reading is correct.
Do not run the heater like this.
