Pentair Master Temp 400 Fault Code


New member
Mar 22, 2021
Los Angeles
I have a Pentair 400 and it has been recently shutting off and I have to recycle AC power to get it back on, and when it turns on I read "273" in the panel display and I dont know what that means (error code?) and when the igniter starts and heater turns on, the water temperature is low, and it wont let me set the target temp.


TFP Expert
Mar 2, 2011
273 might be the stack flue temperature, which is displayed when you push the pool on or the spa on button.

If the number is showing up without pressing the button, the button is probably stuck and you need to replace the keypad.