Pentair Master Temp 400 from heck

[RedAmbition]

We inherited this pool with our new house 2 months ago and I’ve been trying to get the heater working this whole time. It runs for a few minutes before cycling on/off a couple times and then the service heater light comes on. None of the red led’s on the control board come on.

I have replaced the bypass valve, the manifold o-rings, thermistor, thermal regulator, and control board.

I removed the thermal regulator to see if it worked w/o it and it did, so I replaced it, but it still won’t work with the new one installed.

I’m running out of ideas, so if anyone has one I’m all ears!

Thank you!

 

[ajw22]

Have you followed the Troubleshooting charts starting on page 38 of the manual?

Ignitor or ignition control module?

 

[RedAmbition]

Have you followed the Troubleshooting chatrs starting on page 38 of the manual?

Ignitor or ignition control module?

I have. I didn’t think it would be either of those since it does work without the thermal regulator. It stays on and raises the water temp just fine w/o it.

Or am I not understanding what they do?

 

[ajw22]

Could your replacement thermal regulator have been bad?

Have you checked that the heat exchanger is not corroded and leaking?

 

[ajw22]

Bad thermal regulator should show E05 or E06 on panel.

 

[Jimrahbe]

Red,

Can't figure out where that name came from...

Are you running the heater manually or is it being controlled by an automation system?

Thanks,

Jim R.

 

[Rocco]

this sounds very similar to an issue I had with my unit. I had to remove the burner assembly and clean it. There are a bunch of little holes that the gas flow through, if they get dirty or clogged the gas flow is not enough so it cuts off after a few minutes, retries a couple times and then throws the service required light on.

Please let me know if you would like additional details on how to remove the burner assembly.