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Warm Morning Wall Heater LP to NG

alsunne
alsunne Member Posts: 1
in Gas Heating

Has anyone had experience with converting a 1970’s vintage Warm Morning wall furnace from LP to NG? Specifically I need to know the burner orifice size for NG. The furnace is a 65B.

Comments

  • pecmsg
    pecmsg Member Posts: 5,298

    why!

    50 year old furnace I’d be concerned about the intregerty of the heat exchanger.

    Mad Dog_2mattmia2
  • Mad Dog_2
    Mad Dog_2 Member Posts: 7,519

    Penny-wise & Pound fooling. It's not going to have any modern safeties either. Mad Dog 🐕

    Consulting by Mad Dog & Matt Jr.
    mattmia2
  • HomerJSmith
    HomerJSmith Member Posts: 2,635
    edited June 22

    What is your elevation? About 2 drill sizes smaller I would guess. The drill size is stamped on the burner orifice. The lower the number the larger the hole.

    LP gas has twice the heat value of NG, therefore the hole in the orifice of LP is smaller and NG is larger.

    Be aware that a LP to NG may require a change in the manifold pressure regulator spring in the gas valve and you will need to check the manifold outlet pressure to the name plate rating.

    I would check the gas valve manufacturer and go to their literature for a conversion kit if it is even available.

    http://abingdongas.com/online-shop/index.php?rt=product/product&product_id=181

    And get a Carbon Monoxide detector.

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