Reuben's Home Inspection Blog


Where To Find Gas Leaks

Edina House ExplosionThe one home inspection item that consistently causes home buyers to 'freak out' more than anything else is a gas leak. Gas explosions like the ones that recently happened in Edina and Saint Paul are probably the main causes of all the paranoia about natural gas.  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.

Lube Valve Lube Valve 2

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 definitely 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.

Flare Fitting 1 Flare Fitting 3 Flare Fitting 2

Combustible Gas DetectorTo find these gas leaks, I mostly rely on my nose.  If there's a gas leak, I can almost always smell it.  To pinpoint the location of a gas leak, I use a combustible gas detector.  If I see any suspicious work or I run across old or improper gas valves, I just go right to my gas detector, and I quickly check the fittings.

I truly believe that my nose is just as accurate as my gas detector, but I look a little silly running my nose along gas pipes to find leaks.  That's why I use a tool.  If I find a leak with my combustible gas detector, I confirm the leak by using a gas leak detection solution; it's just an expensive blue 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.

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.

RELATED POST: Natural Gas Leaks

Reuben Saltzman, Structure Tech Home Inspections


Comment balloon 52 commentsReuben Saltzman • March 16 2010 05:22AM
Where To Find Gas Leaks
The one home inspection item that consistently causes home buyers to 'freak out' more than anything else is a gas leak. Gas explosions like the ones that recently happened in Edina and Saint Paul are probably the main causes of all the… more
Electric Baseboard Heaters - The Flipper Favorite
When I inspect a home in Minneapolis or Saint Paul that has electric baseboard heat, it's usually a dead giveaway that someone did some remodeling, or someone flipped the house. In fact, the only houses that I run across in the Twin… more
How Serious Is A Cracked Heat Exchanger?
It's an industry standard: if a furnace has a cracked heat exchanger, it gets replaced. The American Gas Association has even put this in writing - they say "Any visible crack or hole is reason for requiring replacement of the heat… more
Drive-By Inspections
"Deal with it now or deal with it later. " That's a phrase I've heard my father, Neil Saltzman say many times. Here in the Twin Cities, there are two primary types of inspections that are done on houses: Buyers… more
Who Inspected Your Roof?
Last week I mentioned that municipal inspectors will sometimes miss important details on permit inspections, partially because they just don't have the time to go over every little detail on a home the way that a private inspector does… more
"… But The City Approved It! "
It happens to me several times each year; I inspect a home for a buyer, I point out a construction defect, then I get a call from an angry seller or seller’s agent, accusing me of being wrong. If someone challenges my call, I’m always… more
Joist Hanger Installation Defects
Just a little over a year ago, I took a class put on by one of the largest manufacturers of metal brackets, Simpson Strong-Tie That class was a real eye opener – I realized afterwards that just about every deck that I inspect is… more
Minneapolis Truth In Sale of Housing - Missing Jumper
One of the most common electrical defects that I find while doing Truth-In-Sale of Housing Evalutions in Minneapolis is a missing jumper wire at the water meter. This is a required repair item, and I often find the repair done… more
How To Fix Double Tapping At Circuit Breakers
Double tapped circuit breakers are one of the most common electrical defects that I find while doing home inspections in Minneapolis and Saint Paul, and they're usually one of the easiest defects to correct. Today I'll explain what… more
Are High Efficiency Furnaces Worth It?
In my blog about window replacements, I made it clear that you'll never get a return on your investment by replacing windows So what about furnaces? If you're replacing your furnace, is it worth installing a high efficiency… more