Pentair mastertemp 250 E05 code

[bennett.tim72]

Hi All, I have a Pentair mastertemp 250 with an E05 code.
I've replaced my stack flue sensor and I still get the E05 code.
My wife tried the heater yesterday with no luck. (E05 code)
I tried it last night and it worked fine for about an hr and a half until the E05 code came on. Checked this am and E05 after about 30 seconds
Nothing blocked in the stack.
Anything else I can check?
My water flow is fine, wondering if i should increase the gas valve?
Any ideas? Thank you kindly Tim

 

[danpik]

A lot of times the error code is because something is wrong with the way the unit is running, not because there is a problem with the sensor. In this case the sensor is probably doing the job as it was designed to do which is telling you that the stack temp may be too high. Now, as to what is causing that is the dilemma. I am not sure what you mean by increase the gas valve.

Sorry I can't be of more help at this time on this one. maybe Paul has some ideas.

Dan

 

[bennett.tim72]

Thanks Dan! I spoke to a Pentair representative, he figures I have calcium build up in the heat exchanger. Hence the high temps in my stack. I agree with you, I feel the sensor is doing its job.
I'll start another thread asking about acid wash your heater!