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Munchkin F09 Error Code

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Alan (California Radiant) Forbes
Alan (California Radiant) Forbes Member Posts: 4,055
edited December 2020 in THE MAIN WALL
We installed this Munchkin in 2006 and it's never been serviced. Received a call from the owner that his heat wasn't working with a F09 error code - "No flame detected". The burner would ignite and then go out right away. I checked the rectification probe, but finally pulled the cover off to see what was going on. While I was undoing the bolts, I looked over at the tridicator and saw that the pressure was dropping. It was then that I heard the sound of water running.




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
SuperTech

Comments

  • JUGHNE
    JUGHNE Member Posts: 11,077
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    After 14 years without service, I would have expected more coffee grounds inside and the rear target wall gone
    kcopp
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,117
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    You got any High-Temperature bubble gum?

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    Solid_Fuel_Man
  • kcopp
    kcopp Member Posts: 4,443
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    Why never serviced?
  • fenkel
    fenkel Member Posts: 162
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    Time for a new boiler.....or find a old used hx...
    What size is the boiler?
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,055
    edited December 2020
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    The owner said that the boiler has never been serviced; curious because the house is fastidiously clean and neat and I've sent him my reminder postcards for servicing.
    The boiler model is a T50M, Munchkin's smallest. Primary/secondary piping; heating only (no DHW).
    We will be replacing the boiler, but the problem is finding a short one. The distance from the center of the flue to the bottom of the boiler is 27".


    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
  • TomS
    TomS Member Posts: 62
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    I wonder what caused the hole in the stainless steel tubing? Can you tell if it started internally or externally?
  • MikefromMn
    MikefromMn Member Posts: 9
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    What does HTP have to offer? I thought those were lifetime warranty on heat exchangers.
  • Canucker
    Canucker Member Posts: 722
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    What does HTP have to offer? I thought those were lifetime warranty on heat exchangers.
    I don't know any warranty that would be in force after 14 years of no service
    You can have it good, fast or cheap. Pick two
  • MikefromMn
    MikefromMn Member Posts: 9
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    I can't see how the heat exchanger leaking was caused by the no service. And 14 years isn't a "lifetime". If the heat exchanger wasn't leaking, I'd think a good cleaning & a new rear target wall would get it up and running.
    Clogged drain from all the coffee grounds no doubt causing the F09. Amazing it ran as long as it did. I'll bet the owner reset it more than once.
  • JUGHNE
    JUGHNE Member Posts: 11,077
    edited December 2020
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    IMO, part of the cause would be the coffee grounds would have insulated the lower section of the HXC from transferring it's share of the heat letting the rest of the coil overheat.

    These things need some serious water flow and have little mass to absorb extra heat. Just start one with the inlet/outlet valves closed and see how quickly you get a lockout.....how do I know this? :o

    (Of course I was just testing the high limit) ;)
    Alan (California Radiant) ForbesCanuckerkcopp
  • archibald tuttle
    archibald tuttle Member Posts: 1,085
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    JUGHNE said:

    IMO, part of the cause would be the coffee grounds would have insulated the lower section of the HXC from transferring it's share of the heat letting the rest of the coil overheat.

    i understand this thought, and I guess if it's looking for a certain outlet temp and you aren't getting all the full heat absorption it's going to ramp up the flame compared to the actual load conditions.

    These are cute reliable little boilers but I never like the credit card the junk into the sump and hope it is not clogged. They would be much more serviceable if there were a couple unions to get the heat exchanger out to work on it. I would keep these things going forever if that were the case (doesn't help them sell their new stuff I guess . . . not saying this was planned obsolescence so much as not thinking of the manufacturing engineer never thinking of the field engineer who has to service this stuff.).