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Miller Gas Furnace (Converted to Oil)

Dale Member Posts: 1,317
Mobile home rated furnaces are tricky. First, all combustion air MUST from outside the trailer, so, CMH has a 4 inch pipe to the roof jack (mobile home speak for vent) then, it MUST have the combustion air from under the trailer. There must be a pipe run to the bottom of the furnace. The louver door is return air only.


  • John Penwarden_3
    John Penwarden_3 Member Posts: 21
    Miller Gas Furnace (Converted to Oil)

    My girlfriend is looking to buy a "fixer-upper" house in Northern NY. The heat is via a Miller Gas furnace (CMF-80-PO-CONV). It is ducted through a conc slab. The furnace does not look that bad, but I am leary of a furnace being located in a small closet. Also, the gas fired water heater is in the same closet as the furnace. The closet is about 2' deep x 6' long. The furnace gets it's air from a louvered opening in the interior wall of the house.

    So, questions are:
    -history/performance of Miller gas heaters (setup for oil)
    -prox to other sources of ignition (water heater, etc).

    I am sure I will have more Q's but those are the first. Oh, and there are no old tickets indicating a routine maint or cleaning has been done.

    Northern NY (Qc, Vt Border)
  • Gene_3
    Gene_3 Member Posts: 289
    if you can

    pull the blower, this us easy on newer units, 2 screws and unplug, slide it out, check the heat exchanger for cracks by looking down into the unit, any cracks are verboten and require unit replacement......why was it converted to oil and still has a gas w/h????? does the gas w/h have an air intake as well?? it should
  • John Penwarden_3
    John Penwarden_3 Member Posts: 21

    My guess is that the orig water heater was elec and died, they then added a 2nd wall mounted LP heater for a converted space (daycare area), and added the water heater (but that is just a guess).

    Hopefully I will be able to check things out a little closer on Sunday.

    Northern NY (Qc, Vt Border)
  • S Ebels
    S Ebels Member Posts: 2,322
    This reminds me of..........

    The CMF-80 reminded me of a sevice call a few years ago that was nearly the cause of my death due to laughter.

    A local slum (trailer) lord called and said he had moved a trailer into his "park" and couldn't get the furnace lit. Said he had looked for a pilot but all he could see was some sparking when it tried to light. The man was redneck enough to make Larry the Cable Guy look like the pope. Sooooo I went over to have a looksee.

    I don't know how else to say this but I found a CMF-80 PO (oil) hooked up to a copper line..................which led outside to the NATURAL GAS METER. I about choked while trying to keep from laughing right in the guy's face. I suppose it couldn't get enough gas through the nozzle to have ever done any damage but I gave him a story about how close he had come to death in order to teach him to leave his hands off stuff he obviously didn't know anything about.

    You can't make this stuff up..........
  • Steve_35
    Steve_35 Member Posts: 546
    We find few of these

    more than 15 years old w/o cracks in the hx.
  • Gene_3
    Gene_3 Member Posts: 289
    trailer stories

    I got one, we got a call at a trailer with the boiler in the bathroom, you know the one you have to sit on the can to service the burner.

    well the guy went to work and left the door open

    he had also left something in the can

    ze toilet would not flush--no water, so we checked and found his main off, when we turned it on water was spraying out of the kitchen sink {musta been why it was off} but we had to flush to be able to work and proceeded to the bath

    the guy I was with flushed and sat on the can and turned towards the boiler, but we both looked at eachother, like telepathy, we both seemed to know that nothing was going down, in fact...it was coming up

    he instantly jumped up in time

    and yep we left
  • mtfallsmikey
    mtfallsmikey Member Posts: 765
    I would...

    Replace it. Look at some other brands, check specifications for clearances, etc. Miller, as well as other mobile home furnaces are rated for close tolerances in closts, and non-combustible floors.
  • JC-TRX250R
    JC-TRX250R Member Posts: 13

    where in Northern NY. If it is close to where I live I would be willing to go check it out for you.
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