Results 1 to 5 of 5
  1. #1
    Join Date
    Jan 2007


    Worked on and installed a lot of waterheaters which where all NG. But was called to a house today to find a propane waterheater with soot build up in chamber. My question is has anyone ran into this issue and what was resolution and why? I checked draft and burners after cleaning, also combustion air and gas pressure which all seem to be ok.

  2. #2
    Join Date
    Jun 2013
    Austin, TX
    Soot is caused by a rich mixture or excessive cooling of the flame, both of which cause incomplete combustion. Make sure it has been properly converted and adjusted to run on propane. A natural gas appliance would run excessively rich on propane.

  3. #3
    Join Date
    Mar 2013
    Springville, NY
    make sure it's a true propane heater, most cannot be field converted. running the fuel tank too low or to empty will also cause sooting.
    Political Correctness, the language of wussies.

  4. #4
    Join Date
    Jul 2009
    Columbia, MD
    What everyone else said. Get a thermocouple switch adapter and wire a low gas pressure switch to it. That way, when the tank runs low it will cut off water heater so it don't soot up

    Sent from my iPhone using Tapatalk

  5. #5
    Join Date
    Apr 2009
    I've seen a few soot up because the control valve did not shut off all the way once the tstat was satisfied. It'd be like a big candle underneath the burner. Some controls do shut off eventually but do so slow enough to do the candle thing part of the time - then little by little the sooted spot grows bigger and bigger. Also, like HVAC_Marc said, be sure it is in fact a "propane" water heater. If it's convertible from nat to lpg be sure the original installer didn't just change the orifice and not also change the spring or the spring setting on the control valve from nat to lpg. If it's built for Nat gas only, (you can't change the spring setting from nat to lp on these) and if someone just changed the orifice to convert it that will definitely cause soot problems.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event