Gas water heaters are extremely effective and cost less to operate than electric water heaters. The one main issue with having a gas water heater in your home is that there is always a chance it could develop a gas leak. A water heater that smells like gas usually indicates that it has a gas leak, but there are a few specific situations where you may temporarily smell gas coming from the unit.

Signs That Your Water Heater Has a Gas Leak

Although natural gas is odorless on its own, gas companies add a type of sulfur-containing chemical compound known as a mercaptan that gives the gas a distinct smell like rotten eggs. If you ever smell this rotten egg odor near your water heater, it is a sure sign that the unit has a gas leak or that the gas line that supplies it is leaking.

Another thing to look for is damage to the gas line leading to your water heater. If the line has anything larger than a pinhole leak, you may also hear a hissing sound caused by gas flowing out of the pipe. You will often be able to hear gas flowing through the pipe when your water heater is running. If you hear this sound when the unit is shut off, it’s also an obvious sign that your water heater has a gas leak.

If there is only a small amount of gas leaking, you may not always be able to smell it unless you’re standing directly next to the water heater. This is why it’s also important to know how to spot the signs of natural gas exposure. Exposure can make you feel dizzy, lightheaded, or nauseous. You may also start to experience severe headaches and throat or eye irritation or have trouble breathing. The exact symptoms you may experience depend on the severity and length of exposure.

What to Do If You Suspect Your Water Heater Has a Gas Leak

If you notice only a faint smell of gas and your water heater is shut off, it likely means that the unit has a leaky gas valve. In this situation, you should immediately close the shut-off valve on the gas supply line and then call a licensed plumber for an inspection. If the problem is due to a leaky gas valve, the smell should go away fairly quickly.

If you notice a strong smell of gas, you should close the shut-off valve and then immediately exit the building. In this situation, you mustn’t turn on any light switches since this could potentially ignite the gas. If you have any pets inside, you should also take them with you when you leave. When you leave, you want to make sure not to close your door. Leaving the door open can lessen the chances of an explosion by allowing some of the gas to escape.

When you’re outside, you should immediately go across the street and at least a few houses down just in case the gas does cause your home to explode. As soon as you’re safely away from your house, you should call 911 or your gas provider’s emergency line to report a gas leak. Either the fire department or the gas company will immediately come out to shut off the main gas valve near your gas meter.

Once your gas supply is shut off, you will then need to have an expert plumber inspect the gas line and your water heater to find the source of the leak. Depending on the source of the leak, the plumber may be able to repair it, or you may have to replace your water heater. A faulty gas valve or a leaking gas supply line are easily fixable issues.

Other Issues That Can Cause a Heater to Smell Like Gas

Depending on the specific model and age of your water heater, you may be able to faintly smell gas when the burner lights. If you have an older unit with a traditional standing pilot light, you should never be able to smell gas when it lights. This is because a standing pilot light ensures that the burner instantly lights as soon as gas starts flowing.

Most water heaters made within the past few years don’t have standing pilot lights and instead use an electronic igniter, such as a direct-spark igniter, a hot-surface igniter, or an intermittent pilot light. Although an electronic igniter should light the burner almost immediately, a small amount of gas may flow before the burner lights. As such, there are times when you may notice a very faint gas smell when the water heater first turns on and starts heating. However, the gas smell should dissipate almost immediately.

If you smell gas for a short time and you don’t hear the burner light, it can be a sign that your water heater has a malfunctioning or worn-out electronic igniter. Gas water heaters that use electronic igniters also have a safety mechanism known as a flame sensor that ensures gas won’t continue to flow if the burner doesn’t light or goes out at any point.

The flame sensor uses a small electrical current to detect the flames produced by the burner. If the flame sensor doesn’t detect the burner flames within a few seconds, it will automatically trigger the gas valve to close and shut off the flow of gas to the burner. This means that gas will still flow for a few seconds if the electronic igniter doesn’t work, and you may be able to smell the gas if you’re standing directly next to the water heater. Again, the smell should dissipate quite quickly.

If your water heater has a pilot light and it goes out, you won’t smell gas. This is because pilot lights have a component known as a thermocouple that serves the same role as a flame sensor. The thermocouple senses the flame from the pilot light and will instantly shut off the flow of gas if it ever detects that the pilot light has gone out.

If you do smell gas when a water heater with a pilot light turns on, it usually indicates that the unit doesn’t have a good enough draft and isn’t venting properly. This can happen because the flue vent pipe is clogged, the wind cap on top of the pipe outside is missing or if the flue is damaged or wasn’t installed correctly. A water heater that isn’t venting correctly is a serious issue because it can lead to carbon monoxide escaping and leaking out into your house. This issue is definitely something you will want to have a plumber check out immediately.

If your water heater has a gas leak or any other issues, you can trust the expert plumbers at AJ Danboise Plumbing, Heating, Cooling & Electrical for help. We repair and service all types, makes and models of water heaters, and we also specialize in water heater installation as well as the full range of plumbing, drain, and sewer services. Give us a call if you need to have your water heater inspected or need any other plumbing, HVAC, or electrical service in the Farmington Hills area.

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