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Can smell gas when I run my new gas heater

I just converted my steam heating system from oil to gas.  I had my old oil burner replaced with a new Carlin EZ-Gas Power Gas Burner, and I kept my old Pensotti R1-4S boiler.  The newly installed burner passed inspection, and after fine-tuning, a test showed 88% efficiency.  The burner is fed by a gas pipe that extends from a new external line installed by the utility company. The exhaust goes out through a new steel liner in the chimney.

The first time I turned on the heater, after 15-30 minutes I smelled methane at the top of the basement stairwell and in the basement next to the heater, so I turned it off.  The heating guy came and did some additional sealing, and now the smell is less distinct (smells more like a mixture of methane and basement smell, instead of just methane like before), but the gas smell is still definitely there. There is no gas smell at all if I leave the heater off. The heating guy says he'll continue sealing it as needed, but I get the impression he's baffled.  Any suggestions about where he could be missing the leak, which I could pass on to him?  Could it be from the gas pipe that feeds the heater (though it only smells when the heater is running), or could it be due to an exhaust leak (though the methane should all have been burned by that point, right?).


  • lchmblchmb Member Posts: 2,513

    get them back. If you are smelling gas please shut it down and call. Have they checked the burner to make sure it's not an actual gas leak on the burner while it's running? Do they have a gas detector?
  • Gordon_Of_EMassGordon_Of_EMass Member Posts: 15
    Don't worry

    I'm not running the heater at all while there's a leak (hope it's fixed by December!).  I'll make sure the heating guy gets a gas detector if he doesn't already have one.  Hopefully it will be able to distinguish between a leak on the heater itself and a couple of inches away where the gas pipe is attached.
  • SteamheadSteamhead Member Posts: 11,380
    Did they tune the burner with a digital analyzer?

    If not, and there is an exhaust leak, you may be smelling aldehydes. These have a smell similar to, but not quite the same as, the odorant they use in natural gas.

    If the above is true, the burner is definitely making carbon monoxide. This, as you might suspect, is dangerous.
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • Gordon_Of_EMassGordon_Of_EMass Member Posts: 15
    The installer gave me a printout of tuning results

    when he was done tuning the burner, with amounts like 4.6% O2, 9.3% CO2, 25 PPM CO etc. and 88% efficiency.  I have two CO detectors, and they're functioning OK.  I think I recognize the smell to be gas odorant (from the gas pipes or heater), but the installer said he'll check the chimney and liner just in case it's the exhaust.
  • lchmblchmb Member Posts: 2,513
    pressure test

    I think for my own piece of mind I would do a pressure test on the gas lines also...
  • SteamheadSteamhead Member Posts: 11,380
    88% efficiency

    sounds like the boiler might be under-fired. What was the stack temperature? Did he install a proper gas barometric damper with blocked-flue switches on the chimney connector?

    Take some pics and post them.
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • Tim McElwainTim McElwain Member Posts: 3,904
    Get the local gas company

    to come in and test the system and they also have Combustible Gas Detectors which can test the ambient air for gas and also the pipes to the equipment. They will also do a tight test on the system.

    Watch out for things like loose tubing connections that are only affected when the unit is running. The gas company will know enough to check all of that.
  • BobCBobC Member Posts: 4,453
    make sure they check everything

    Last year i was helping a friend rewire his son's house fore phones and we noticed a gas smell at the top of the cellar stairs. We went outside and opened up the outside cellar door and started to investigate. This is a 2 family house and the hot water heaters had both just been replaced so I started to test the pipe joints for leaks. I found one of the gas unions finger tight and leaking.

    Tightening up that union fixed the leak, they called up the installer to come back and verify everything and he did so but was a bit red faced.

    Mistakes happen, sometimes it's the simple things that get you.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Gordon_Of_EMassGordon_Of_EMass Member Posts: 15
    The flue temperature

    was 196 degrees F. according to the test readout.  (INLT 113.6 F., NETT 82.4).  There's no barometric damper.  There was one before when I had oil heat, but it was removed when the gas heater was installed.
  • Gordon_Of_EMassGordon_Of_EMass Member Posts: 15
    I suspect it's the gas pipe

    that feeds the heater. When I turn the heater on briefly (just to test for the gas smell), I don't smell gas right at the heater, but I smell it on the side of the heater where the pipe is attached.  The pipe doesn't have any sealer on the joints, and I suppose the joints could be loose.

    When the heating guy brings over a combustable gas detector, I'll make sure we check the pipes along with everything else.
  • SteamheadSteamhead Member Posts: 11,380
    Too low

    you're getting some serious condensation in your boiler and chimney if it's really that low.And the draft will go out of control unless you have a barometric.
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • Gordon_Of_EMassGordon_Of_EMass Member Posts: 15
    They covered over the draft opening

    that's why they removed the damper.  There's no air intake to the flue now.  I'll check with the burner guy about the low flue temp.
  • Gordon_Of_EMassGordon_Of_EMass Member Posts: 15
    It turned out the burner was defective

    and was missing two gaskets and a couple of other parts.  That's why the gas smell wouldn't go away.  My heater guy said he has installed around 10 Carlin gas heaters, with no problems until now.  Carlin will replace it with a new one.
  • njwebdevguynjwebdevguy Member Posts: 33
    Units combustible gas sensor measures?

    Do any of you know what units are typically found with low gas leaks? I am pricing combustible gas detector modules and I want to get a feel for what ranges in PPM that I should be looking for. I think that I might be able to design a combustible gas detector for a very modest cost, but I need to see if it would be sensitive enough.

    Some of the sensors Ive seen in the past for CO are not that sensitive at all. Not worth the $$$..

    I want it to be able to be sensitive enough to get a background reading that is nonzero - to know that the thing is working.
  • Tim McElwainTim McElwain Member Posts: 3,904
    Are you looking

    to test the ambient environment? If so most gas testers are set up to give readings in % gas or LEL (Lower Explosive Limit) or UEL (Upper Explosive Limit) then it depends on the gas you want to test.

    Natural Gas explosive limits are between 4.5% (LEL) to 14.5 % (UEL) gas as compared to air ratio.

    LP is 2.15% to around 9.5% as compared to air ratio.

    You can make a methane detector too sensitive and you will begin to get a reaction from even pipe dope.

    There are also allowable levels of leakage on gas valves not detectable by smell or normal test instruments This has to do with the permeability of the valve seats in the gas valves and the ANSI allowable leakage standards. A detector made too sensitive would cause gas valves to be changed that have nothing wrong with them. This has occurred from time to time by the way until those who know step in and stop the insanity One job actually had four (4) gas valves changed.

    Typical procedure for detection is that if any reading of 2% or less you ventilate the area and proceed with testing. Any reading in excess of 2% you evacuate, secure sources of ignition and alert gas personnel and first responders for further investigation.

    The type of situation in this posting would have been better located by having a professional gas combustion power burner expert service the unit. The installer of the burner should have detected this gasket issue immediately upon firing the unit.

    Bottom line if you smell gas and do not have a working gas detector then evacuate and call the professionals. Entering a building which smells of gas without a detector is insanity. You nose does not measure % gas.

    By the way glad the problem was found and a new burner should solve the problem.
  • gennadygennady Member Posts: 680
    edited November 2011
    gas smell

    besides gas smell, barometric draft regulator must be installed with manual reset spill switch mounted on the bottom of draft regulator.

    88% is too high, 80%-82%  is ok. low exhaust temperature leads to condensation and low draft..
    Gennady Tsakh

    Absolute Mechanical Co. Inc.
This discussion has been closed.


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