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Where To Look For Gas Leaks

By In Gas Leaks - How To Find On March 16, 2010


Edina House Explosion The one home inspection item that consistently causes home buyers to ‘freak out’ more than anything else is a gas leak.   Believe it or not, small gas leaks are actually quite common at old houses, and they’re usually simple for a plumber to fix.  Today I’ll share the most common locations for gas leaks, and I’ll share my home inspection techniques for finding gas leaks in old Minneapolis and Saint Paul homes.

The most common place for me to find gas leaks is at gas valves.  Older style gas valves that aren’t allowed any more today are often referred to as lube valves or plug valves.  If you have a Truth-in-Housing Evaluation performed in Minneapolis and the evaluator marks down “old gas valves” or “unapproved gas valves”, this is what they’re referring to.

Lube Valve

Lube valve

These valves are easily identified by a nut or spring on the valve across from the handle; newer gas valves don’t have these.  I would estimate that I find leaks at about one out of every five of these valves.  Gate valves, which should only be used for water, are also common offenders.

Gate Valve

The repair is always simple – replace the the valve.  In Minneapolis, if the appliance being served by an improper valve is replaced, the valve must be replaced at the same time.

The second most common location for gas leaks is at unions.  A gas union is a fitting that provides a disconnection point for a gas appliance.  If the union doesn’t get tightened enough, it will leak.  Notice the bubbles in the union below?  That’s a small gas leak.

Leaking Union

Flare fittings are the last common offender.  Here in Minnesota, soft copper gas tubing is allowed just about anywhere, but it takes a little more skill to properly install soft copper than other types of gas piping.  For a flare fitting, copper tubing gets flared out at the end and connected with a flare nut.  If this connection gets bent or isn’t tight enough, it will leak.  For the record, that nut pictured below isn’t the right type of nut for a gas line… but it’s what I had sitting in my parts drawer as I was writing this blog.

Flare Fitting 1 Flare Fitting 3 Flare Fitting 2

Combustible Gas Detector To find these gas leaks, you can usually rely on your nose.  If I smell a gas leak and nobody is around, I’ll run around the fittings with my nose right up the gas line.  This is a fast way of figuring out exactly where a leak is coming from.  The only problem with this method is that I look very silly doing it.  When I’m inspecting a house and my clients are with me, I use a combustible gas detector.

The only problem with using a combustible gas detector is that they’re ridiculously sensitive, and they’ll often give false positives.  For instance, if there is fresh pipe dope at a fitting, the gas detector will go off.  When one finds a leak with a combustible gas detector, it needs to be confirmed by using a gas leak detection solution; it’s a liquid that does about the same thing that dish soap would – it bubbles if there’s a leak.  To make it easier for the repair person coming in behind me, I also mark the location of the leak with orange electrical tape, and I write “Gas Leak” on the tape, along with an arrow showing exactly where the leak is.

Gas Leak

I’ve heard stories about appliance connectors leaking, but I’ve never found one that leaked. Next week I’ll talk about defects with appliance connector installations.

Reuben Saltzman, Structure Tech Home Inspections – Email – Minnesota Home Inspector

        



About the Author

Reuben

Reuben is a second generation home inspector with a passion for his work. He grew up remodeling homes and learning about carpentry since he was old enough to hold a hammer. Reuben has worked for Structure Tech since it was purchased by Neil in 1997, and is now co-owner of the company. Reuben’s favorite customers are the ones who have a lot of questions; he grew up thinking he was going to be a school teacher because he enjoyed teaching others so much. In a sense, that’s a lot of what home inspections are about, so Reuben truly does what he loves. Reuben has an A.A. degree in liberal arts and has attended most of the Building Inspection Technology classes at North Hennepin Community College. Reuben and his wife are the proud parents of two young childen, Cy Alexander and Lucy Nicole, and have a German Shepherd named Stanley. With two young children Reuben doesn’t have much free time, but he still tries to play disc golf as often as possible during the summer. Reuben lives in Maple Grove, MN. Professional Qualifications / Memberships: *ASHI Certified Inspector *President, ASHI Heartland Chapter *Member, Minnesota Society of Housing Inspectors (MSHI) *Licensed Minneapolis Truth-in-Sale of Housing Evaluator *Licensed Saint Paul Truth-in-Sale of Housing Evaluator *Licensed Maplewood Truth-in-Sale of Housing Evaluator *Licensed Hopkins Truth-in-Housing Evaluator *Licensed Robbinsdale Point of Sale Evaluator *Affiliate Member, Southern Twin Cities Association of Realtors

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9 Comments

  • Vickie White 1 YEAR AGO

    Thanks for the article. The gas company found two gas leaks In my house, they shut the gas off and took the meter, which was fine with me. I have friend that does this type of work, my question is, will the gas company accept his work.

  • Neil Elliott 2 YEARS AGO

    How do you find and fix a gas leak in the wall. My house has no basement and no attic.

    • Reuben Saltzman 2 YEARS AGO

      Neil - you would probably need to open up the wall.

  • alisa 5 YEARS AGO

    There seems to have been an epidemic of explosions in Mass this past winter. I heard that it was because the regulators were inside the houses, and not performing correctly. whereas, if they are outside the home, and not performing correctly, the gas is let out into the atmosphere, instead of building up inside the home. thank you for your tips on this matter!

    • Reuben Saltzman 5 YEARS AGO

      No kidding? I wonder what was different about this winter that caused the explosions.

  • Reuben Saltzman 5 YEARS AGO

    Hi Linda, Thanks for reading! If you're going to hire someone to check for gas leaks, make sure it's a licensed plumber that can also repair any potential leaks. I'm guessing this would be less than $100. Having said that, I don't think you need to hire anyone to come in. If you have a gas leak, you should be able to smell it. You can buy the leak detection solution that I mentioned in my blog at Home Depot for about five bucks, and you can swab this on any suspicious areas. Good luck!

  • Linda Merry 5 YEARS AGO

    Reuben, Great article! Lots of good information. On average, what should it cost to have someone come in and check for leaks? My home is over 60 years old and would love to put my mind at ease. Shoot! I just had the house inspected for refinancing. Probably could have gotten some info then... Thanks, Linda