Ambient Combustable Gas

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Permalink Reply by Bud Poll on December 22, 2011 at 1:40pm

Hi Dmitri,

I have to agree with you in not liking the ticking indicator, I guess I've been an analog meter guy for too many years.  But I was able to resolve my concerns about natural gas by reading the levels that are of concern.  Basically, our meters are more sensitive than we need.  However, I prefer it that way as even a small leak could be an indicator of bigger problems.  If the meter picks up something and ticks a bit faster we need to tell the home owner to have it checked and fixed.  If it screams, we need to get out.  In between it is difficult to know what to do without an actual reading.

I'll be watching to see if others can fine tune that a bit better.

Bud

PS on another forum the poster referred the modest indication to the appropriate gas company and as it turned out, their meters couldn't even see what the auditor was picking up and thus refused to take any action.

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Permalink Reply by David Meiland on December 22, 2011 at 11:35pm

Your unit may have been malfunctioning, and the best way to find out is to send it back to the manufacturer for service. Sniffers are sensitive to a surprising number of chemicals. Try putting a Sharpie marker under its nose.

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Permalink Reply by Thomas Price on December 27, 2011 at 9:09am

Spray the fitting with soapy water and check for bubbles.  The detector only indicates the likelihood of a leak.  The bubbles are proof positive.  Always flag any leak with marker tape and have the owner call the gas company or plumber.

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Permalink Reply by Bob Kretvix on December 29, 2011 at 9:14am

Dmitri

Gas leak detectors are generalized meters which can detect a wide variety of combustible vapors, not just natural gas and propane. Alcohols, gasoline, paint solvents, nail polish remover, aerosol propellants (e.g., butane) are examples.  Usually the meters have a minimum detection at about 50 ppm, some lower. 

Other chemicals used in the house can therefore set these off.  Its possible that methane from sewer gas may also be entering the house from broken, disconnected or even missing sanitary vent pipes. 

So your readings (or alarm) may be correct. You'd have to know the minimum detection limit on your model, then check to see if there are chemicals or cleaners being used that might interfere with "normal" ambient readings.  But I would have to say that consistent readings of even 25+ ppm in a home from these interfering chemicals is unlikely unless there is some type of painting, auto repair or significant plumbing malfunction going on. 

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Permalink Reply by Allan G Hurst on January 5, 2012 at 3:42pm

I too had a similar experience. Same equipment (TIF 8800). I had located leaks at meter, then found several common leak locations at DHW. In walking through the house I started getting alerts from the wood floors. I ventured (adventured) into the crawlspace finding nothing in the area I could access. I attached meter to pole and extended it through vent locations. With no alerts I noted my findings and suggested a plumber be contacted.

After a night of restless sleep, I returned the following day. I repeated the previous day's procedure. No unexpected alerts on this day. Talking with the homeowner, I discovered she had recently cleaned the floors in preparation for holiday guests. Though health and safety were my concern, she was quite proud of her shiny floors......Allan

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Permalink Reply by Tom Barrett on January 6, 2012 at 2:56pm

I stuck my gas leak detector under my armpit to hold while I was doing something and it went off. Think I should soap this area to confirm that I have a leak there?

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