I have an odor in my house that smells almost like natural gas, but is not natural gas. I called the gas company in my area and had them come out to test for gas leaks. Long story short, they found no evidence of a leak. Anywhere. They checked all of the gas lines from the meter to all of the gas appliances as well as evry single connection. They even checked the connection on my propane tank to my grill.
The odor is the strongest by the front entry to my house and the refrigerator in the kitchen (which is around the corner from the front door). It has been sporadic and faint in the past, but today the odor was so strong, it gave me a headache and made me a little loopier than usual just from standing in front of the fridge to get a drink of water. The odor is still pretty strong hours after the guys from the gas company left.
Any help or suggestions anyone can provide would be helpful.
Is there a drain nearby that doesn’t get regular use? If the trap dries out, sewer gas can get in. I have a couple I have to add water to periodically.
Natural gas is odorless. The gas company adds an odored compound, usually methanethiol, so that leaks get detected. Any thiol will smell similar, and they are very potent. Many sulfur compounds have a similar smell, including hydrogen sulfide. Decomposing organic matter will make hydrogen sulfide. It could be coming from a sewer or backed up drain.
No unused drains in the house, so that’s a no go. We just remodeled the kitchen, so no dead mouse behind the fridge either (and I think that would nix the coolant leak as well).
And you are correct WarmNPrickly. The additive of choice here is mercaptan. But still getting the rotten egg smell. I did check the eggs too and they are fine.
Could be a dead mouse in the wall. I had one behind the circuit breaker that started off just like this. It was fine for a month and a half when we moved in, but as the weather got warmer it got worse. At first it was an occasional smell, then it became almost unbearable. We knew about the dead mouses behind the circuit breaker from the inspection, but I had assumed it had desiccated. Out of desperation I went behind the circuit breaker to move it. I was surprised to find that the smell went away.
What’s under the house in that area? Basement with nothing interesting, crawlspace with dead critters, gas pipes?
Question for everyone: how foolproof is a gas company at detecting leaks? My first thought is “they just didn’t find it” but I don’t know how they check.
We once had a strong gas smell in our yard, apparently in the breeze coming from the school building across the street. We called the Fire Department, who agreed with our assessment, and called the Gas Company. The Gas guy was all over the yard with meters and jigawatt sensors.
45 minutes after our first phone call, the source was located: dead squirrel upwind just outside the yard. I had no idea corpses could produce that particular odor.
If you’re in a small suburb type city you could call your fire department. If you explain the situation, I’ll bet they’d be more then happy to come out with their meters and double check.
Also, if you’re not using your furnace right now another option is to just go and cut the gas at your meter and see if the smell goes away in a few hours…and if it is a gas leak, it probably will take a few hours for the smell to dissipate even with the windows and doors open. Leave it off overnight and if the smell is still gone in the morning, turn the gas back on and see if it comes back on.
Since the smell is next to the fridge, if you have a gas stove, I’d guess that’s where it’s coming from (if there is, in fact, a leak). If you can easily get to the shut off for that (like if it’s in the basement) you could try just turning that off for a while.
I had something similar a few years ago: at first, just the faintest whiff of something that might be gas, that built over a few days to a definite pong.
I knew it wasn’t actually gas, because we had an electric oven, but it took days to track down the source: a small clove of garlic had slipped into a tiny crack between a shelf and the wall, and started to rot.
Wrong. Yes natural gas is largely methane that is odorless. However natural gas is a natural product that contains varying amounts many contaminates giving it its typical smell. As fields came into production containing very little odor, the gas companies began adding compounds to aid leak detection.
I’ve no doubt that large quantities of natural gas will smell like hydrocarbons, but by the time you are smelling those, you are at an explosion risk. Methanethiol, on the other hand, can be smelled at parts per billion levels. Hydrocarbons do not smell like sulfur. There may be some natural gas fields where sulfur is a component, but the hydrocarbons themselves are comparatively odorless.
I have spent extensive amounts of time in older NG fields, and they reek. You have admitted I am right. Your flat statement that natural gas is odorless is wrong if natural gas from any source has a odor.
Note, some spray cans at least at one time were pressurized with natural gas.
Run the taps in the kitchen, and smell the water as it is coming out, especially the hot water. You may have sulfate-reducing bacteria in your water heater, or sometimes in a well if you use well water. It is harmless, but they convert natural sulfates in the water into hydrogen sulfide gas, which is released when you run the tap.