Additional Diagnostics for Pentair Master Temp Heater E05 error code


New member
May 11, 2017
Just joined, and was impressed with the content in reviewing a Pentair Master Temp 200 E05 heater error message I had.

The previous threads were helpful, but here are a couple of other things to check when seeing an E05 code

-check your physical connection on the Stack Flue Sensor (SFS) spade plugs...I had the E05 code, bought two replacement sensors (luckily) inserted one, still had the E05 error code!...did a could of things, but one was to remove new sensor and re-seat the two wires...turns out one of the wires did not crimp onto the spade connector and though it was loosely inserted, it wasn't connected. Tried the second sensor, worked fine! Sending the new (bad one) back for replacement!

-some of the previous threads refer to LEDs on back of board...get a mirror out, and look at the back of the board...there are a handful of LEDs that light up, for me the SFS was that was indeed the problem

-I have a variable speed pump...make sure it it running fast enough to push enough water through the heater...though not a specific error tied to E05, it was listed in the manual as something to verify.