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  1. #1
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    392

    Majestic Dv360 lp conversion

    I got a call to troubleshoot a majestic dv360 that the homeowner had "someone" convert from NAT to LP. The issue is that the pilot flame is big and yellow. It has the proper orifice (62) and the pressure is good.
    Any sugesstions?
    Common sense is NOT common !!!

  2. #2
    Join Date
    Dec 2011
    Location
    PA
    Posts
    199
    Check the out pressure while unit is running to confirm that they changed the valve head. If pressure is good, the pilot is not getting enough air. clean pilot thoroughly.

  3. #3
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    392
    Thanks Vader. They "supposedly" installed the conversion kit, but I did not have have my torx security bits with me to verify the proper installation.
    This is why I hate curing "tinkeritus"!

    I did notice that the main burner did not turn down when I tried to adjust the main flame. It is a SIT 820 valve. I will have to make a return appearance in the next few days and would like to be armed with all the ammunition that HVAC Talk can offer!!! :-)

  4. #4
    Join Date
    Aug 2004
    Location
    S.E. Pa
    Posts
    6,141
    I agree with verifying primary aeration first. I would remove the pilot orifice spud and visualize the bore of the pilot burner down to the primary aeration port below. With the pilot tubing disconnected from the valve, you can blow the entire tubing clear including the pilot burner. Verify the correct pilot orifice again and replace PMI. You can use an old pilot tube compression adapter and a short tube to make an adapter to your manometer for direct pilot pressure readings right out of the valve. Since the house line pressure translates directly to the pilot pressure minus the pressure drop of the piping, this is a major determinant to your pilot flame. You can have a partial obstruction in the valve vestibule or knob that restricts gas flow to the pilot while the inlet pressure into the valve is spec. Also, there is a small cotton filter between the valve vestibule and the pilot tube attachment. If this gets clogged with moisture, condensibles, or particulates, you will have to replace the valve as it is not field serviceable. That's why I like to get a direct pressure reading right out of the valve to the pilot and compare with line pressure. When I say line pressure, I mean before the SIT valve. Those pressure taps on the valve see about a 1wci drop.

    If the gas inlet pressure under full load is acceptable, and there is no appreciable restriction through the SIT valve, I'd probably replace the entire pilot assy.. Keep in mind pressure, as measured with a manometer, does not guarantee flow. A manometer can read adequate pressure but a restriction may not allow sufficient flow.

    HTH,

  5. #5
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    392
    Thanks Hearthman!!! I have never read what the pressure to the pilot is supposed to be......now I know.

    This is a newly fired fireplace that sat unused for 5 years. I replaced the orifice with another with the same number with no difference. I did take out the pilot orifice and looked inside, but could not see any obstructions. I carry a couple of those pilot assemblies in my service truck and will hook one up to the valve to see what happens after checking the pilot pressure at the valve.

    Thanks guys!

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