Pentair Minimax NT E004

6 years ago

I have replaced the upper plenum, fan, pressure switch, ignitor, flame sensor, and I cleaned all 8 burners of dirt dobbers and rust. The heater worked a few times and now one month later I again get error code 004 after it tries to cycle on 4-5 times. After the purge cycle, the fan shuts off for about 15 seconds and then I hear the fuel gas ignite. When the fan does not turn back on shortly after ignition, the fuel gas trips off. After 4-5 times, I get the E004 code. Can someone tell me what to do to get this problem fixed. I do not see anything wrong with the hose. Also, I cleaned the burner valve as best I could.

Comments (7)

  • JMarko

    After reading several of the other posts with similar problems, I again cleaned out all the burners and orifices. I also replaced the hose to the fan/ pressure switch just in case there was a small hole. I just put it all back together and still get the same problem. The gas trips off shortly after it lights because the fan does not switch from low speed to high speed quickly enough. Any suggestions for the next step. I was thinking it may be the controller (expensive item) or possibly the Honeywell gas valve.

  • muddy_water

    Have you called Pentair?

  • muddy_water

    Check the stack flue sensor.....

  • JMarko

    I don't see any stack flue sensor in the manual. I don't think this model has one.

  • muddy_water

    I guess I was thinking of a Master temp...Sorry...Try the link below

    Here is a link that might be useful: Pentair

  • JMarko

    Thanks, I will check that link. Last weekend, I got the heater running by lowering the fuel gas pressure at the manifold by turning the adjustment counterclockwise inside the valve. I went in 1/4 increments until the heater started. I then ordered a 0-15" wc gauge so that I can make sure the pressure at the manifold is at 2.0 " wc. Once it arrives, I will post again to let you know if this fixes the problem. Hopefully, it will consistently fire up properly if the pressure is right.

  • coltar15

    When you get Pentair on the phone and tell them your model number, there will probably be a pause, and a sigh.,from the tech. Don't let that bother you.
    Seriously, that can be a hard heater to trouble shoot. Get help.

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