Page 1 of 2 12 LastLast
Results 1 to 15 of 18

Thread: Water heater pilot went out-

  1. #1

    Water heater pilot went out-

    Woke up to barely warm hot water this morning. The pilot light on our barely 4 year old 40 Gal AOSmith water heater was out. The pilot re-lit easy enough, and the burner fired up like it should. And about 10 seconds after it fired, the 'howling' started, as usual... ever since I installed it, the thing howls every time the burner fires, I'm assuming something to do with the rush of hot air going up the flue and heat expansion causing some vibration. Anyway, all normal. I'm on the floor looking in the window and the flame is quite yellow, and for several minutes I could hear hissing, exactly like water on a hot skillet. My first thought was the tank is leaking from the inside- BUT, there's no trace of any water ever having been in the catch tray, no calcium tracking, no water marks on the heater. I figure if the tank WAS leaking from the inside, it wouldn't just leak while the burner was on, water pressure would keep pushing it out. Also, after about 5 minutes during the reheat the hissing stopped...

    So my next guess is condensation within the burner is the source of the hissing water. And it makes sense I guess, the coldest it's been in the last 4 winters has been like 15, and right now it's brutal cold outside, got down to like 1 overnight and most of yesterday it never got above 15, so I'm guessing the extra-cold water coming into the water heater may have caused some condensation to form within the burner, and some of it dripped onto the pilot, snuffing it out...

    I'm just wondering if the condensation theory sounds plausible, and if anyone else has had something like this happen? Not sure how to deal with this other than hope it warms up outside and the pilot stays lit!

    At least this heater has one of those 'pilot-on' indicators, a blue light that blinks every 3 seconds as long as the pilot is lit, and the heater is in plain view, easy enough to check during the day-
    ========================================
    ELEVEN - rotary cutter tool machines
    FOUR - CO2 lasers
    THREE- make that FOUR now - fiber lasers
    ONE - vinyl cutter
    CASmate, Corel, Gravostyle


  2. #2
    Join Date
    Feb 2003
    Location
    McKean, PA
    Posts
    15,030
    The howling and vibration is likely caused by the water boiling under the accumulated calcium and other mineral deposits in the bottom of the tank. The pilot going out could be caused by back drafts if the roof shield isn't in place or back drafts in the stack due to a missing hood or hole in the flue. A weak thermocouple could also cause the pilot light to go out.
    Last edited by Lee Schierer; 01-31-2023 at 12:52 PM.
    Lee Schierer
    USNA '71
    Go Navy!

    My advice, comments and suggestions are free, but it costs money to run the site. If you found something of value here please give a little something back by becoming a contributor! Please Contribute

  3. #3
    Quote Originally Posted by Kev Williams View Post
    ... looking in the window and the flame is quite yellow, ...
    Flame color would lead me to believe your gas supply may be a bit sketchy. Might warrant a call to your utility.

    As for condensation, water vapor and CO2 are primary byproducts of Nat Gas (mostly methane) combustion. If the flue is cold enough, the water vapor may condense prior to exiting the flue. Could this drip on the pilot??? I'll leave that to your eyes.

    Or do you just have off spec gas supply and pilot blows out from turbulence of heat cycle cut-off?

    ******
    ETA - Some further pondering: flame color may be poor fresh air flow :: not enough O2. I could only speculate as to cause. ...I've owned 10 or six water heaters; no howlers in the lot.
    Last edited by Malcolm McLeod; 01-31-2023 at 1:09 PM.

  4. #4
    After the burner was on awhile and the hissing stopped, the flame was mostly blue like it should be. Pretty sure the gas supply is fine. I have a wall mounted ventless 22,000 btu NG heater in my garage shop, connected to the same gas line, it's flame is always blue, as are all 5 burners on our GE gas range...

    This was the first time a pilot has ever went out in this house that I can remember since 1969. Current Goodman furnace has a piezo igniter, as does the range, the water heater and the garage heater have pilots-
    ========================================
    ELEVEN - rotary cutter tool machines
    FOUR - CO2 lasers
    THREE- make that FOUR now - fiber lasers
    ONE - vinyl cutter
    CASmate, Corel, Gravostyle


  5. #5
    Water vapor can cause discolored pilot light. When we run humidifier in house, flames on gas stove turn kinda orange. You shouldn't have any condensation on center tube of WH, as it's in contact with the warmed water. Due to extreme cold, last of flue gasses, or air from inside the house rising thru vent pipe, could be condensing on vent pipe, running down inside center tube The incoming water contacts bottom of the tank, which could cause condensation. Have you contacted AO Smith about your problem?
    Last edited by Bruce Wrenn; 01-31-2023 at 4:50 PM.

  6. #6
    Join Date
    Feb 2014
    Location
    Lake Gaston, Henrico, NC
    Posts
    8,033
    Howling sounds like a check valve.

  7. #7
    Join Date
    Sep 2016
    Location
    Modesto, CA, USA
    Posts
    8,640
    Your gas company should come out and check stuff for free.
    Bill D

  8. #8
    Join Date
    Sep 2007
    Location
    Longview WA
    Posts
    26,298
    Blog Entries
    1
    A weak thermocouple could also cause the pilot light to go out.
    Another problem related to the thermocouple is the clamp that holds it in place. If the screw is loose the thermocouple will not generate current as well and may cause the safety shut off to close the gas line and kill the pilot.

    Many years ago my gas water heater needed the screw holding the clamp for the thermocouple tightened every few years.

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

  9. #9
    2 mornings later-- I just washed off some operator panels I'm making which kicked on the water heater-

    Flame has some yellow in it but it's not mostly yellow. Analyzed the stove flame, occasional small yellow flame tips occur pretty much always-

    I specifically listened for any hissing, there was none whatsoever. Only hiss at all was the gas entering the burn chamber...

    --and it howled, as usual! (I'll have to record it, it's very similar to the 'howl' of blowing across the opening of glass cider jug, just louder!)

    Just an anomaly it seems
    ========================================
    ELEVEN - rotary cutter tool machines
    FOUR - CO2 lasers
    THREE- make that FOUR now - fiber lasers
    ONE - vinyl cutter
    CASmate, Corel, Gravostyle


  10. #10
    in case anyone cares, found the problem...

    after 3 more pilot outages in the past 3 weeks, 2 of them lighting off burner gas in scary, loud fashion, last one earlier today, I thought about getting a tankless. Only problem with that, there's hardly any available without waiting 3-4 days!

    So I go to light the pilot again, only this time it simply wouldn't light, just a faint wisp of flame occasionally. This went on (and off) for nearly 2 hours. Told the wife I suspected, HOPED, that the pilot tube was just dirty, but I didn't want to shut all the gas off in the house just to check the pilot tube.

    Then it dawned on me... no thermocouple, no gas delivery unless I push the 'pilot' knob in
    Pilot tube seals with a ferrule fitting so no tape needed, so I grab a wrench and remove the tube from the Honeywell controller. No smells. Push the Pilot button, immediately got smells. Wiped the end of the tube off, put 'er up to my lips, and blew... Not a whole lot happened, but I didn't expect to blow much thru a .010" hole, so I tried some suction. At least when the suction grip quit I knew it wasn't totally plugged up. Gave it another push for good measure, and screwed the tube back in...

    Much to my surprise, after 2 hours of nothing, I pushed the Pilot button, waited 5 seconds or so, and the pilot fired up first click of the piezo. And the pilot flame was noticeably bolder than before. It's actually quite visible thru the sight window, before I could hardly see it..

    My theory (conjecture) is that the weak pilot flame was being pushed sideways under the shroud by the residual air in the burner chamber being moved around by the incoming NG- and the 'hidden' flame wouldn't light off the gas until the air finally got moved out of the way enough, and by then there was too MUCH gas, which just went BOOM, and blew out the burner AND the pilot flame...

    After a few minutes I turned the knob to 'medium hot' and the burner simply lit with no drama whatsoever. Dirty pilot tube, nearly spent $1400 today for that!

    A tankless is still in our future, this one still howls
    ========================================
    ELEVEN - rotary cutter tool machines
    FOUR - CO2 lasers
    THREE- make that FOUR now - fiber lasers
    ONE - vinyl cutter
    CASmate, Corel, Gravostyle


  11. #11
    Join Date
    Sep 2007
    Location
    Longview WA
    Posts
    26,298
    Blog Entries
    1
    Great Kev, now some other folks may benefit from your experience.

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

  12. #12
    Join Date
    Mar 2019
    Location
    Los Angeles, California
    Posts
    770
    I love my Noritz tankless. Its 20 years old and works like a champ. With the savings in gas, probably paid for itself a couple times over. You will have to de-scale it once a year or use a scaling filter and de-scale it less frequently but still every couple years.
    Regards,

    Tom

  13. #13
    Join Date
    Feb 2008
    Location
    Colorado
    Posts
    164
    Somewhat Unrelated to your issue, but in case it might help others, on our previous water heater, we frequently had “flame outs” when we had high winds here — not uncommon in the high mountains. Easy to restart, but tricky to coach the wife to do so when I was a thousand miles away. Apparently wind would blow down the flue and extinguished the pilot flame. New water heater has an electronic ignition and haven’t has an issue since.

  14. #14
    Join Date
    Mar 2014
    Location
    Iowa USA
    Posts
    4,218
    Most pilot problems come from insects and such building cobwebs inside the burner orifice area or line or just plain dirt.

    I will never have a tankless water heater.... why the huge gas/electric line needed for one, the lime issue for us folks in hard water country.

    When our gas bill for heating water is $20 per month, where is the savings?? It takes X Btu's to heat one gallon of water to X degrees regardless, our water heater is hi Eff 40 gallon and can store what little hot water we require at next to nothing cost. The tiny pilot helps keep that already heated water warm.
    Retired family of 2 with lots of laundry and a daily dishwasher run.

    If we paid $100's to heat water, sure... maybe.
    Last edited by Bill George; 03-02-2023 at 7:08 AM.
    Retired Guy- Central Iowa. , Cloudray Galvo Fiber , WorkBee 1000x750 CNC Router - Mach4 - Windows 10

  15. #15
    Join Date
    Sep 2009
    Location
    Medina Ohio
    Posts
    4,388
    I put a circulating pump on my water heater and have pretty much instant hot at all the faucets. It does seem to save on the water bill as I used to have to wait 30 seconds for hot water in my bath and 45 in my wife's bath. gas usage has stayed about the same.

Posting Permissions

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