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Munchkin 926 control board upgrade

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hmontena
hmontena Member Posts: 5
Have been getting issues with 2006 Munchkin 80M with 925 board. F18 fault which is gas valve failure. this occurred about 6 times, reset and things were back in operation. My heating man and I agree that it sounds like the board. Went in to verify that all the wiring connections were secure. Has been running. I purchased a 926 board upgrade. The vendor told me that I had to purchase a '926' wiring harness.

Is this a fact? The wiring harness is different? The color codes and schematics look to be the same. The controller is the only difference? If so I will return the $115 harness.

Thank you for your help, Herb

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  • HomerJSmith
    HomerJSmith Member Posts: 2,511
    edited December 2019
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    I think he means a new display panel and display cable?

    Yes, the 926 board need a new display panel and comes with a new ribbon cable. The display panel that you get with the kit is a naked board that fits into the display console. You have to take out the 4 screws in the display console and put the new 926 display board in the shell, removing the old 925 display board, first.

    As I recall any cables necessary for the conversion to a 926 board comes with it, with the exception of the display board and cable.

    A part # of the cable you have would be helpful.
  • HomerJSmith
    HomerJSmith Member Posts: 2,511
    edited December 2019
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    The problem with the 80M was that the Honeywell gas valve vent would touch the back of the boiler cabinet and that would close off the vent hole. The vent is a 1" brass end tapered projection out of the gas valve toward the rear of the black boiler cabinet.

    The fix was to shift the heat exchanger so that the nipple wouldn't touch the back of the cabinet or drill a 3/8" hole in the black boiler cabinet thru the inside shell, only, where the nipple touched, thus allowing air circulation around it.

    That could have very well been your problem.
  • hmontena
    hmontena Member Posts: 5
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    Thank you Homer, that is interesting I will look. More head scratching on the computer finds that the ribbon cable and small board are different. The big harness is the same. I will put it into stock. So it can collect dust for a few decades.

    Thanks again everyone, Happy New Year !!