pentair minimax 400 natural gas heater

[coreyparker]

[h=2][/h]

I have been having problems. the unit is around 13 yrs old. I just replaced the Ignition mod and the therm board. I have checked all sensors and found them to be in working order. I thought maybe the gas valve is going bad. The heater runs and then the service light comes onIt will restart after a few minutes and continues this cycle. Please help. Thank you​

 

[ps0303]

With intermittent problems like this, you need to be monitoring the voltage on the sensors as one of them is dropping out for a second or two. It's going to be hard to catch the one acting up and might take you some time to find it. You could jumper one out at a time and let the unit run and if the unit stays running with X sensor jumped out, that's your problem child.