Dealing with a Water Heater Gas Leak: Symptoms, Causes, and Solutions

Gas water heaters are a common appliance found in many homes and businesses that use natural gas or propane as a fuel source to heat water.

While they are generally safe when properly installed and maintained, they can pose a risk of gas leaks. Gas leaks from water heaters can be dangerous, as they can lead to the buildup of explosive gas in enclosed spaces and can also cause carbon monoxide poisoning if the gas is not properly vented.

According to CDC, annually in the US, at least 430 die and 50,000 seek emergency medical attention due to accidental carbon monoxide poisoning.

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In this context, it is important to be aware of the signs of a water heater gas leak, as well as the steps you can take to prevent and address this problem.

Unless you have the knowledge and the right tools, it is not recommended to attempt a DIY repair but to leave the repair work to trained professionals.

Water Heater Gas Leak: What You Need to Know

Potential Dangers of Gas Leaks

Natural gas and propane are the two most commonly used types of gas for water heaters. While these appliances are generally safe and reliable, they might leak gas, so it is important to take necessary precautions to ensure their safe use.

Leaking natural gas is hazardous due to its combustibility and potential for explosions. Even a small leak can cause fire or explosion, leading to property damage, injuries, or fatalities. Additionally, natural gas is odorless and colorless, making it challenging to detect when released. Fortunately, utility companies add a chemical compound called mercaptan as an odorant to natural gas to make it easier to detect when it leaks.

In enclosed spaces, gas leaks can displace oxygen and cause asphyxiation, which can be fatal.

Exposure to natural gas chemicals, including benzene, toluene, and formaldehyde, can lead to health problems such as headaches, dizziness, and nausea, among other symptoms.

Furthermore, methane, the primary component of natural gas, is a potent greenhouse gas that contributes to climate change. Leaking natural gas can significantly increase methane emissions, leading to environmental issues such as global warming.

If you have a propane water heater, note that leaking propane gas, as flammable and explosive substance, is also dangerous.

As opposed to natural gas, propane is typically stored as a compressed liquid in tanks, and leaks can occur due to tank damage, faulty valves or connections, or natural disasters such as earthquakes or hurricanes.

It is heavier than air and can accumulate in enclosed spaces, leading to a higher risk of explosions and fires. If propane escapes into a basement or crawlspace, it can pool in low-lying areas, leading to a high concentration of propane gas that can easily ignite with the slightest spark.

Propane gas is a flammable and explosive substance that, when leaked, can easily ignite, leading to fires, explosions, and significant property damage.

Exposure to propane gas can also cause health problems, such as headaches, dizziness, nausea, and respiratory issues, particularly if the concentration of gas is high.

Common Signs of a Water Heater Gas Leak

Understanding the symptoms and signs of a water heater gas leak can help you identify the problem early on. Here are some common signs:

  • Smell of gas: Natural gas is odorless, but gas companies add a distinctive odorant-mercaptan (it smells like sulfur or rotten egg) so that people can detect a gas leak.
  • Hissing sound: If you hear a hissing sound near your water heater, it could be a sign of a gas leak. This sound is caused by gas escaping from the pipes or connections.
  • Rusty or corroded pipes: If the pipes or connections near your water heater are rusted or corroded, they may weaken and become more prone to leaks.
  • Yellow or orange flame: The flame on your gas water heater should be blue. If you notice that the flame is yellow or orange, it could be a sign that the gas is not burning properly and leaking out of the system.
  • Soot or carbon buildup: If you notice soot or carbon buildup around your water heater, it could be caused by incomplete combustion and escaping gas.
  • Physical symptomsPhysical symptoms such as dizziness, nausea, and headaches can be signs of a gas leak from a water heater. This can release toxic gases such as carbon monoxide, which can lead to serious health problems or even death.

Common Causes of a Gas Leak

Water heater gas leaks can have various causes, and it’s essential to recognize the potential issues that may arise. Properly identifying the root cause of the problem is crucial for adequate repair and prevention of future leaks. Here are some of the most common causes:

  • Loose or damaged gas supply lines: A loose connection between the gas supply line and the water heater can cause gas to escape. Gas supply lines can also become damaged over time, leading to leaks.
  • Faulty gas valves: If the gas valve is faulty, it can allow gas to leak out.
  • Corrosion or rust on the water heater tank or pipes: Over time, the water heater tank or pipes can develop rust or corrosion, which can create weak spots that allow gas to leak out.
  • Poor installation or maintenance practices: If a water heater is not installed or maintained correctly, it can lead to gas leaks. For example, if the gas supply line is not properly secured, it can come loose and cause a problem.
  • Wear and tear on the water heater over time: Like all appliances, water heaters can experience wear and tear over time. This can lead to cracks or other damages.
  • Damage to the water heater from external factors such as flooding or earthquakes.
  • Human error, such as leaving the gas supply valve open accidentally.

Steps to Take If You Suspect a Gas Leak

If you suspect a gas leak from your water heater or any other gas appliance, it is important to take the following steps immediately:

  • Turn off the gas supply valve: Locate the gas supply valve near the water heater and turn it off. This will stop the flow of gas to the appliance and help prevent further leakage.
  • Evacuate the area: Leave the building immediately and avoid using any electrical switches or appliances that could ignite a spark. Also, do not attempt to find the source of the leak yourself.
  • Contact the gas company or emergency services: Call the gas company or local emergency services immediately and report the problem. They will send a qualified technician to assess the situation and fix the problem.
  • Seek medical attention: If you or anyone in the building is experiencing symptoms of gas exposure, such as headaches, nausea, dizziness, or difficulty breathing, seek medical attention right away.

Prevention Tips

Preventing a water heater gas leak can help ensure the safety of your household. Here are some prevention and maintenance tips:

  1. Schedule regular maintenance and inspections: Have a qualified technician inspect and maintain your gas water heater at least once a year. This will help detect any potential problems early on and ensure that the appliance is functioning properly.
  2. Install a gas leak detector: Consider installing a gas leak detector (available on near the water heater. These devices can detect even small gas leaks and alert you with an audible alarm or visual indicator.
  3. Ensure proper ventilation and airflow: Make sure your water heater is properly ventilated and has adequate airflow around it. Blocked or restricted air intake vents can cause incomplete combustion and increase the risk of gas leaks.
  4. Avoid storing flammable materials near the heater: Keep any flammable materials such as paint, gasoline, or cleaning products away from the water heater. These materials can ignite and cause an explosion or fire.
  5. Educate yourself and others: Educate yourself and your household members about safety and prevention. Know how to recognize the signs of a gas leak and what steps to take in case of an emergency.


It is important to take water heater gas leaks seriously and not overlook any warning signs. Therefore, if you suspect a gas escaping the system, it is crucial to take immediate action by turning off the gas supply and seeking professional assistance.

Additionally, if you have not had your water heater inspected or maintained in a while, it is recommended to schedule an appointment with a licensed professional to ensure it is operating safely and efficiently. By taking these steps, you can protect your home and family from the potential dangers of gas leaks.

Remember, safety should always be a top priority, and proactive measures can help prevent accidents and protect those you care about. Don’t hesitate to take action and prioritize the safety of your home and loved ones.


Why My Water Heater Smells Like Gas, But There Is No Leak?

The gas smell from a water heater may not necessarily indicate a gas leak, but instead may come from a different source such as a problem with the pilot light or burner, other appliances, or nearby gas pipelines. It’s important to take any gas smell seriously and leave the area immediately if detected. Seek professional assistance from your gas company or emergency services to inspect and determine the source of the gas odor.

Is a Small Gas Leak Dangerous?

Yes, it is. Even a slow gas leak can lead to symptoms such as headaches, dizziness, nausea, fatigue, and breathing difficulties, and in severe cases, it can cause unconsciousness, coma, or even death. Additionally, an electrical spark or any source of ignition can trigger an explosion. If you suspect a gas leak, evacuate the area immediately and call your gas company or emergency services for assistance.

Can I Repair a Water Heater Gas Leak Myself?

If you suspect a gas leak from your gas water heater, it is not recommended to attempt a DIY repair. This can be extremely dangerous, and it is important to take immediate action to ensure the safety of yourself and those around you.
It is important to prioritize your safety and the safety of others, and not attempt a DIY repair in this case. Gas leaks can lead to serious injury or even death, and it is best to leave the repair work to trained professionals.

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