Harmon ESP, Red vs Black

[Bill Bennion]

Is there a benefit to the Red ESP over the Black ESP on a PB 105. I do have a newer board.

 

[Overfireinthehole]

Not really just make sure dipswitch 5 is set to on for a red wire or off for the black or white. The red one is a k type thermocouple and the old black ones were a thermistor type, basically the same as your room sensor. Tcouples increase in resistance with heat and thermistors decrease in resistance with heat. Now I’ve never worked on your specific model but I’m pretty sure the different boards handle the different probes the same way.

 

[MSmith66]

depending on the control board that you installed will depend on the ESP probe used. The new board should have had a paper with it telling you what ESP probe color to use and what Dip switches to turn on/off. The wrong ESP probe will have your combustion blower running ALL the time, even when the stove is to be off many hours later.

 

[rickwai]

The red probe is a little larger in diameter. It requires drilling the hole out. Usually it is not in a easy place to get a drill into. I just use the same as it had if replacement is needed.