Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Gas hissing from water heater combustion air inlet area

mick04u
mick04u Member Posts: 17

Is it normal to hear a faint gas hissing from the combustion air inlet area around the bottom of my water heater when it's not running? If I turn off the pilot light, it goes away. As soon as I press the control knob to relight, it starts again. Is it normal for it to hiss like that from just the pilot light gas feed? The pilot light looks normal.

Mad Dog_2

Comments

  • Intplm.
    Intplm. Member Posts: 2,572

    Not necessarily a bad thing. It could just be the way the pilot light sounds. However, there could be a leak somewhere on the gas valve and or tubing feeding the burner/pilot light.

    Spray this on the valve and tubing etc. to check for leaks.

    mattmia2
  • mick04u
    mick04u Member Posts: 17

    There are no bubbles at the tubing connections at the valve. I also don’t hear a hissing at the valve area. The hissing appears to be coming from inside the combustion chamber where the pilot and burner are located. If the pilot is staying on and there’s a leak somewhere in the combustion chamber, you would think it would ignite.

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 17,466

    Possibly the pilot is too large. Turn the temperature down to keep the main burner off and listen for the noise with the pilot on then turn it off and see how the noise is. If the noise is from the pilot I wouldn't worry

    Intplm.
  • mick04u
    mick04u Member Posts: 17
    edited March 10

    It only makes the noise when the pilot is on and the main burner is off. If I turn off the pilot, it goes away. So probably nothing to worry about?

  • Larry Weingarten
    Larry Weingarten Member Posts: 3,780

    Hi, One thing I don't see mentioned so far is the tubing connection at the pilot end of things. These can leak too. The Neanderthal (pre OSHA) approach would be to use a long fireplace match or similar, and move the flame past that fitting. If nothing lights, good. Placement of that connection is such that it would not necessarily be lit by the main burner firing. Also, I've seen leaks along the length of the pilot tube, so the entire length needs to be checked. The noise itself doesn't have to mean something is wrong, but as mentioned above, it could mean the pilot flame is too large.

    Yours, Larry

    Long Beach Ed
  • HVACNUT
    HVACNUT Member Posts: 6,670

    I believe this is sealed where the lines go in. Spark pilot? It would be impossible for you to test for leaks without removing the whole assembly.

    Its not normal to hear the pilot hissing when everything is closed up. How old is the water heater? It needs service.

  • mick04u
    mick04u Member Posts: 17

    It’s brand new and I just installed last week.

  • mick04u
    mick04u Member Posts: 17

    And yes, it has a spark igniter.

  • mick04u
    mick04u Member Posts: 17

    What’s also odd is that there’s a red line from a marker right next to the pilot burner window (see attached photo). I wonder if something was flagged upon inspection and it was never fixed.

  • mattmia2
    mattmia2 Member Posts: 12,191

    the line is usually made when they check something.

  • mick04u
    mick04u Member Posts: 17
    edited March 11

    If it’s leaking, it has to be leaking from the burner tube inside the sealed burner chamber because it stops if I turn off the pilot and starts back up when I press the temperature knob to reignite the pilot.

  • Larry Weingarten
    Larry Weingarten Member Posts: 3,780

    Hi, As your unit has a flex connector for the main burner, you could remove the unit from the combustion chamber and hook it up, then test for leaks.

    Yours, Larry

    HVACNUTLong Beach Ed
  • hot_rod
    hot_rod Member Posts: 24,800

    could it be water dripping onto the hot metal of the burner or pilot assembly?

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • mick04u
    mick04u Member Posts: 17

    No, it’s a steady hissing.

  • hot_rod
    hot_rod Member Posts: 24,800

    I agree with @EBEBRATT-Ed a high pilot flame. Any gas leaking inside I think would have been discovered by now, if it ignites

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • HVACNUT
    HVACNUT Member Posts: 6,670

    Call them back. Its sealed. You shouldn't hear the pilot. I've never heard the pilot on that type and I've got good hearing.

    Can you post a pic of the pilot light?

  • mick04u
    mick04u Member Posts: 17
  • SuperTech
    SuperTech Member Posts: 2,563

    Pilot flame looks normal to me in that picture.

  • Intplm.
    Intplm. Member Posts: 2,572

    Well…this just might be the way the thing sounds and there might not be anything wrong at all?

  • HVACNUT
    HVACNUT Member Posts: 6,670

    I see 2 Blue spots on the very left edge of the pic.

    SuperTech
  • SuperTech
    SuperTech Member Posts: 2,563

    Good eye. I didn't notice that. That's definitely not normal and could be the source of the problem.

  • mick04u
    mick04u Member Posts: 17

    That’s just the reflection of the pilot light. See photo.

  • HVACNUT
    HVACNUT Member Posts: 6,670

    That's a reflection? Ok if it is, but IMO, with a sealed chamber, you shouldn't hear the pilot light. Not unless you were down on the ground looking for it.

  • mick04u
    mick04u Member Posts: 17

    I am hearing it from the bottom vent holes.

  • mick04u
    mick04u Member Posts: 17
    edited March 13

    Yes, that is a reflection off of the metal clamp that holds the gas tube.
    My neighbor has the exact same water heater and no hiss, so it can’t be normal. I do notice that the pilot tube has a small kink/crimp in it just before it connects to the valve, but I see that on other Rheem water heaters too, so not sure if it’s normal and why it would be there though. I wonder if mine is crimped more than others and that’s what’s causing the hiss. The only other thing I can think of it is it’s leaking somewhere inside the combustion chamber and the gas is rising up through the flue before it can ignite. And that may also be why I’m not smelling it. At this point, I may just return it and replace it with a State water heater from my local supply warehouse. This is a Rheem from HD. Rheem offered to reimburse me to have a plumber out to look at it, but I have to pay upfront and wait 4-6 weeks for reimbursement.

  • Mad Dog_2
    Mad Dog_2 Member Posts: 7,893

    Ok..where is this job? I'm getting antzy...Mad Dog

  • mick04u
    mick04u Member Posts: 17

    Virginia Beach, VA

    Mad Dog_2
  • Intplm.
    Intplm. Member Posts: 2,572

    I guess a good thing to do would be to use some bubble spray leak detector on the gas connections at the gas valve, on the gas valve and any where else that might be in question. This, done for safety reasons and is easy enough to do. Next, check for proper gas pressures (Inches of WC) and service the thing. Clean up the inside and out. Also look for a gas valve malfunction or flow of gas obstruction. And if it still makes the noise…leave it alone.

  • ChrisJ
    ChrisJ Member Posts: 16,554

    It's been over 20 years since I heard it, but I recall the furnace in my parent's house hissing from the pilot light.

    I remember it because for the first 24 years of my life I always heard that noise when I walked by it until I suddenly didn't. It was silent.

    The pilot had gone out.

    It's an odd thing to remember, but yeah. The pilot light most certainly had a noise.

    Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.

    Mad Dog_2
  • Mad Dog_2
    Mad Dog_2 Member Posts: 7,893

    Dan Foley..Lorton Virginia..best I can do...mad Dog

  • Larry Weingarten
    Larry Weingarten Member Posts: 3,780
    edited March 15

    Hi, Another thought. Search for "gas leak detector" on ebay. Here's an inexpensive one in the right style: https://www.ebay.com/itm/126252749873?_skw=gas+leak+detector&itmmeta=01JPD1HYC50Y9KPX5G9N1X3FRS&itmprp=enc%3AAQAKAAAA8FkggFvd1GGDu0w3yXCmi1fMTs7Wk4VYAzpfq95FwCGni7hh6v27Fm5wNiiHb3l0SPwqipz7Mz5eUwD%2FaxTa9xtgQqRI5krP7pZvV%2Fc0cv19FjyWmcFS8xVYERmp%2Fs5hyG1FMqM61S6%2FMgb3a1Jg34utadq5pHwPZhHeP4XX7MeZBBteLhBisRpIS79C1QzOkd4e9%2B76wvJ4Fv%2Bq6ilGYtpF%2BDykXGMIudoW9VSBsOKtD%2F%2Bz%2BHOzp2nsr4RPx8MsMA8WxBW5FAEMr3zdu8wNRPH1HxkWMlqUnpa3PuyaiQ23%2FYQKUr2oriGslSx6yo5V0g%3D%3D%7Ctkp%3ABFBMyubHobNl

    Now, use it to check down around the combustion chamber and gas valve. Also, with the main burner not running, check up at the top of the heater, under the draft hood. If the noise is a gas leak, you'll know. But you'll also now have a useful tool! 😽

    Yours, Larry

    mick04u
  • mick04u
    mick04u Member Posts: 17

    I checked with the gas leak detector you recommended. I only get a reading from the flue at the top of the water heater when the burner is on. When it’s off and only the pilot is on, I get nothing.

  • Larry Weingarten
    Larry Weingarten Member Posts: 3,780

    Hi, This is probably good news. It suggests you aren't hearing a gas leak, but just pilot operation. 👍

    Yours, Larry

    Intplm.