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Munchkin boiler

tclougherty
tclougherty Member Posts: 7
edited April 13 in Gas Heating

I have a munchkin boiler that is 20 years old. I replaced the combustion blower, the heat exchanger, and several components. The boiler is in good shape. I’m now looking at an issue with the F 10 and F09 Faults.. The boiler will start and run through the cycles and work, but when it goes from HI fire, Low fire and then shuts down and then tries to restart, it will fault. I can see the spark and the heat exchanger will light, but then it goes into fault. I’ve replaced the rectifier as well as the igniter and checked all grounding connections. Any advice is appreciated.

Comments

  • mattmia2
    mattmia2 Member Posts: 12,559

    what did the combustion analysis show? how often has the combustion side of the hx been cleaned?

  • tclougherty
    tclougherty Member Posts: 7

    combustion was checked and boiler cleaned annually

  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,403

    Have you opened up the boiler and poured water through the HX? If the drain is slow or clogged, you can get an F09.

    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab

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