Mastertemp 400 not starting w/ automation (not staying on w/ manual)

[jwelch649]

Hello,

My Mastertemp 400 is not firing up when asked to do so via Intellicanter. All the lights light up and the code displayed is r02 for about 2-3 seconds then it goes blank with no heater activity (see attached pic). If I manually push pool or spa on the heater panel, it fires up and heats for a minute or 2 before completely shutting down with no error codes. I've replaced the stack flue sensor and high limit switch.

Any thoughts on where to start troubleshooting?

Thanks!!

 

[ajw22]

Normal boot-up is 888, 128, and then rX, where X is the software revision number.

I suspect your membrane keypad is bad and a key is stuck powering it off after it tries to turn on.

Read Pentair MasterTemp Heaters - Further Reading

It describes how you can disconnect the keypad and jump the pins to simulate the keypad.

Knockoff non-Pentair keypads are inexpensive on Amazon.

Let us know what you find.

 

[jwelch649]

Thanks @ajw22 for the reply! It ended up being the Control Board. I got one at Amazon for $78 and it is working perfectly (for now). I'll certainly roll the dice on long term success to save ~$350.

Very much appreciate all the knowledge I've found here at TFP!!