Stay Safe: What to Do If Your Water Heater Smells Like Gas?

Have you ever noticed a distinct smell of gas coming from your water heater? If so, it can be alarming and concerning.

A gas smell is not something to be ignored, as it can indicate a potential gas leak and pose a significant danger to your household.

In this article, we will explore the possible causes of a gas smell from your water heater and the importance of taking immediate action to ensure your safety.

gas burner with the blue flame
photo: Pixabay

By the end of this article, you will have a better understanding of what to do if you detect a gas odor and the importance of regular maintenance and inspection of your unit.

So, if you are curious to know more about this issue and how to address it, keep reading.

What You Need to Know When Your Water Heater Smells Like Gas

Possible Causes of a Gas Smell from a Water Heater

When your water heater smells like gas, it is a cause for concern and should not be ignored. It is important to identify the possible causes to avoid any potential danger and ensure the proper functioning of your gas water heater.

There can be various reasons why your unit emits the smell, ranging from a gas leak in the system to old or malfunctioning parts, and it is crucial to determine the root cause of the issue.

  • Gas leak in the system – The most common why your water heater smells like gas is the leak. The leak can be caused by a damaged supply line, a damaged gas valve, or a damaged burner. If it is coming from your unit, it is important to take immediate action to avoid any potential danger.
  • Improperly installed gas line or water heater – A gas smell from a water heater can also be caused by an improperly installed supply line or unit.
  • Dirty burner or pilot light – Another possible cause of the odor is a dirty burner or pilot light. A dirty burner or pilot light can cause incomplete combustion of gas, leading to the production of carbon monoxide gas, which is odorless and can be deadly.
  • Faulty thermocouple: The thermocouple is a safety device that shuts off the gas supply if the pilot light goes out. If the thermocouple is faulty, it can cause the pilot light to go out and the gas to build up. Check the thermocouple and replace it if necessary.
  • Old or malfunctioning water heater parts – Over time, the parts can wear out or malfunction, causing gas to leak out or combustion to be incomplete.

Signs of Gas Smell from a Water Heater

When it comes to detecting a gas smell from a water heater, there are several signs that you should look out for. These signs include:

  • Unusual odor: If you smell a gas-like odor coming from your water heater, it is a sign of a potential gas leak. The smell is usually similar to that of rotten eggs, which is caused by the presence of sulfur in natural gas. In general, natural gas is odorless, so utility companies add a chemical called mercaptan to give it a distinct, sulfur-like odor. This odor is used to alert people to a gas leak.
  • Pilot light discoloration: A healthy pilot light should be blue in color. However, if you notice that the pilot light is yellow or orange, it could be a sign of incomplete combustion, which can lead to many problems.
  • Hissing or hissing sound: If you hear a hissing or whistling sound coming from your water heater or near the supply line, it is a sign of a gas leak. The sound is usually caused by gas escaping from the unit.
  • Carbon monoxide detector alert: A carbon monoxide detector can alert you to the presence of carbon monoxide, which is a byproduct of incomplete combustion. If your carbon monoxide detector goes off, it could be a sign of a gas leak from your water heater.
  • Other signs include dead plants or vegetation near the gas line.

It is important to pay attention to these signs and take immediate action if you notice any of them. Ignoring these signs can lead to serious consequences, including fires, explosions, and carbon monoxide poisoning. Inhaling high concentrations of carbon monoxide can lead to headaches, dizziness, nausea, and even death.

If you suspect the leak or notice any of these signs, it is crucial to turn off the gas supply, evacuate the premises, and contact a licensed professional to inspect and repair the issue.

Regular maintenance and inspection of your water heater can help prevent gas leaks and ensure your safety.

What Causes a Gas Smell When There Is No Gas Leak?

It’s important to note that in certain circumstances, you may detect the scent even in the absence of a gas leak. This can occur due to a variety of factors, including but not limited to:

  1. Pilot light: If you have a gas stove or furnace, a small amount of gas is always present in the pilot light. If the pilot light is not burning correctly or has gone out, gas can build up and cause a smell.
  2. Dirty burners: Gas appliances can accumulate dirt and debris on the burners over time, which can interfere with the gas-to-air ratio and cause incomplete combustion, resulting in a gas smell.
  3. Overused appliances: If you have been using your appliances extensively, they may emit a smell due to natural gas odors building up within the appliances.
  4. Sewer gas: Sometimes, what smells like gas is actually sewer. Sewer gas contains methane, which is similar in smell to natural gas.
  5. Chemical odors: Certain chemicals can produce a gas-like odor that can be mistaken for gas. For example, some cleaners and solvents contain chemicals that emit a gas-like smell.

Precautions to Take When You Smell Gas from Your Water Heater

If your your water heater smells like gas, it is important to take immediate precautions to ensure your safety. Here are some precautions you can take:

  • Do not use any electrical devices or switches: If you suspect a gas leak, do not turn on any electrical devices or switches. This can create a spark, which can ignite the gas and cause an explosion.
  • Turn off the gas supply: Locate the gas supply valve near your water heater and turn it off immediately. This will stop the flow of gas to your unit and prevent further leaks.
  • Open windows and doors: If it is safe to do so, open windows and doors to ventilate the area and allow the gas to dissipate.
  • Evacuate the area: If the smell is strong, evacuate the area immediately and call the utility company or fire department from a safe location.
  • Do not attempt to fix the problem yourself: Gas leaks are dangerous and should only be handled by licensed professionals. Do not attempt to fix the problem yourself. Instead, call a licensed plumber or HVAC technician to inspect and repair the problem.


If you suspect a gas leak from your water heater, it is important to turn off the gas supply immediately and contact a licensed professional to inspect and repair the issue. Do not attempt to fix the issue yourself or use any electrical devices or open flames near the area. It is crucial to evacuate the premises and call emergency services if you detect a strong gas smell or have symptoms of carbon monoxide poisoning.

Regular maintenance and inspection of your water heater by a licensed professional can help prevent the leaks and ensure the safe functioning of your unit. If your water heater smells like gas, it is essential to address the issue promptly to avoid any potential danger and ensure your safety.


Why My Gas Water Heater Smells Like Burning?

If your gas water heater is emitting a burning smell, it may be due to a clogged burner, a malfunctioning valve, or a buildup of debris in the combustion chamber. Other potential causes include a faulty flue or venting system, which can cause overheating and produce a burning smell.

My Water Heater Smells Like Burning Plastic

If your water heater is emitting a burning plastic smell, it could indicate a problem with the electrical components. They have electrical components such as a thermostat, heating element (in some models), and wiring that can malfunction and produce a burning plastic odor. Another possible cause could be overheating of the insulation around the electrical components, causing it to melt and emit the burning plastic smell.

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