+ Reply to Thread
Results 1 to 5 of 5
  1. #1
    Join Date
    Sep 2007
    Posts
    8

    Default Water heater gets 'confused'

    Greetings -

    Got an interesting problem that I'm finally willing to try and solve.

    We've got a 4+ year old propane water heater (came new in our new house), and ever since we've had it, it occasionally gets into a state where you'll use some hot water, and the exhaust fan will kick on, but the burner won't fire. The exhaust fan will then fun forever, as it seems to think the burner is on and needs to run. I go down and flip the on/off switch, and it fires right back up in the correct state. If you peek in the fire hole when it is in the confused state, there is flame in there - I'd describe it as more than a pilot light amount of flame, but far less than full blast when it is working right. Maybe the difference between your simmer burner and your rocket burner on your gas stove.

    Back when we first moved in, it seemed like 3 or 4 times a year it would get cranky like this, and do this make 3-4 times over the course of a week or so, then it would go away and work fine.

    Slowly over time, the frequency has increased, and the length of the time before it seems to resolve itself has increased as well. Seems to not have anything to do with weather, seasons, load on the the water heater, etc. Probably just a failing bit of electronics.

    Anyway, before I have someone out, I'm hoping to see if anyone might have any idea if this is minor or major.

    thanks,
    -- robert

    P.S. Might be meaningful: I've never drained the whole thing, but a couple times a year I drain a few gallons, and they're always crystal clear.

  2. #2
    Join Date
    Aug 2007
    Location
    The Great White North
    Posts
    4,045

    Default Re: Water heater gets 'confused'

    which water heater do you have?
    Does it normally have a standing pilot light?
    "" an ounce of perception -- a pound of obscure "
    - Rush

  3. #3
    Join Date
    Aug 2007
    Posts
    1,131

    Default Re: Water heater gets 'confused'

    Without anymore info concerning the WH as of yet....and without getting too involved in technical explanations concerning the firing sequence of these critters and the parts involved...you might give this a try -

    Turn the breaker off to the unit or unplug it and then remove every spade-lug electrical connector you can find and clean/polish the male contact surface with some very fine grit sandpaper or a piece of fine grade steel wool....or similar. Then plug the wire back on. Do these one at a time as you don't want to get things misconnected.

    Same for any/all wiring harness plugs you find. Disconnect them and clean the connectors as best you can.

    If that doesn't do the trick, then more info concerning the specifics of the WH will be necessary to help with diagnosis. It sounds like the necessary 24 VAC is not getting to your main gas valve or it is but the solenoid is hanging up rather than opening freely. Which and why is the question.
    Last edited by goldhiller; 10-22-2008 at 11:37 AM.

  4. #4
    Join Date
    Sep 2007
    Posts
    8

    Default Re: Water heater gets 'confused'

    My apologies for the slow response, been away for a bit. Anyway, here are the vitals:

    Bradford White, 40 gallon:
    MITW40L6CX12

    (How sad to read the expected operating cost at the expected propane price of $0.93/gallon.)

    I'll try and squeeze in some cleaning of the connections this afternoon. It'd be nice if that solved it!

    thanks,
    -- robert

  5. #5
    Join Date
    Sep 2007
    Posts
    8

    Default Re: Water heater gets 'confused'

    Quote Originally Posted by rwyatt View Post
    Bradford White, 40 gallon:
    MITW40L6CX12
    Actually, I think it is M1TW... (I read the 1 as an I).

    Poked around the Bradford White website and found the service manual for this kind of water heater, and they basically suggest what you suggested - open her up and clean out the contacts.

    http://www.bradfordwhite.com/images/...8_39935_00.pdf (2M PDF warning)

    There's a paragraph in there that describes exactly my behavior. It'll try to fire once, if that fails, again in 6 mins, and yet again 6mins after that, at which point it gives up, but it keeps the blower motor running.

    cheers,
    -- robert

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •