Does gas leak when pilot light goes out on water heater?

Author: Izabella Yundt  |  Last update: Monday, June 22, 2026

The thermocouple is a key component of any water heater. It's what closes the gas valve when the pilot light goes out. This safety feature is included with the valve so gas won't just leak out if the flame isn't there anymore.

Will a gas leak if the pilot light goes out?

If the pilot should go out, gas is immediately shut off to the main burner, however, there is still a small amount of gas that will continue to flow to the oven pilot. All free standing pilots are approved by the American Gas Association. There is not enough leakage to create a hazard.

What happens if a water heater pilot light goes out?

If the pilot light goes out, the gas will stop flowing and your unit will shut off. When heating is required, the gas control valve releases the gas into the main burner where the pilot light ignites the gas. Apart from lighting the main burner, the pilot light also provides warmth to the thermocouple.

Why does it smell like gas when the pilot light goes out?

If the pilot light is out and you smell gas, you have a leak or a bad gas valve, since the gas valve is supposed to turn off the pilot gas if it goes out.

How to tell if your hot water heater is leaking gas?

Signs of Water Heater Gas Leak

The most obvious sign is if you smell gas in or around your house. Gas will typically smell like rotten eggs, a smell added by the gas company in order to help make the gas more identifiable when there is a gas leak.

FREE Fix! Pilot Light That WON'T STAY LIT on Water Heater

Is it normal to smell a little gas from water heater?

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.

What are the symptoms of a gas leak?

Natural Gas Leak Physical Symptoms
  • Ringing in your ears.
  • A reduced appetite.
  • Pain in the chest.
  • Nosebleeds.
  • Blistering or pale skin.
  • Flu-like symptoms.
  • Dizziness.
  • Breathing difficulties.

Does smelling gas always mean a leak?

In some instances, the smell of gas may be present naturally. However, leaks can occur, and we want to make sure they are resolved as quickly as possible. Natural gas is odorless, but an additive called mercaptan is included to alert people of leaks.

Should I hear gas when lighting pilot?

Once the knob is depressed, you should smell and potentially hear gas flowing to the pilot. Keeping the knob pressed in, use your opposite hand to press the igniter button until you see that the pilot flame is lit.

What does it mean if you smell gas but there is no gas leak?

If you smell gas near an appliance, it may be just a pilot light that has gone out or a burner valve that is open slightly. If you find this problem and can fix it, the problem may be solved. If you smell gas inside: Go to a phone that is not near the smell and call your local gas company right away.

Do I need to turn gas off if the pilot light goes out?

All furnaces made within the last 20 years or so are typically equipped with a failsafe electrical shut-off valve. This valve operates automatically and shuts off gas flow as soon as the pilot goes out, preventing any risks of excessive gas buildup.

How to tell if gas is on a water heater?

Another way to identify your water heater type is to look for a pilot (flame). To do this, you will need to locate the access panel on the unit and see if you can spot a bluish flame – if you do, then you are seeing a gas-powered unit in action.

How much does it cost to replace pilot light on water heater?

Water Heater Pilot Light Replacement

Replacing the pilot light in a water heater should cost between $75 and $150. The pilot light might go out for various reasons on your gas water heater. It's rare for a heater to require a full replacement of the pilot light assembly.

Does a water heater leak gas if the pilot light is out?

The thermocouple is a key component of any water heater. It's what closes the gas valve when the pilot light goes out. This safety feature is included with the valve so gas won't just leak out if the flame isn't there anymore.

How do you check for a gas leak in the air?

Bubbles in water

A good way to check whether you have a gas leak is to perform the 'bubbles test' with soapy water. Simply mix some dish soap with water, and spray or put the solution in the area you think is leaking. If you start to see bubbles showing up, then it's an indication that you might have a gas leak.

What happens if a gas leak goes unnoticed?

YOUR GAS BILL IS HIGHER

Gas leaks are subtle in smell but very obvious in bills. They can even go on for months undetected. But if there's a significant amount of gas escaping from your system, it can cause a spike in your gas bill. Pay attention to any sudden changes in your monthly invoice.

Will I smell gas if my pilot light is out?

If the pilot light goes out on a storage or instantaneous hot water heater, space heater or a ducted heater, you will not have a gas leak. This is because all modern gas appliances with pilot lights have a fail-safe device that closes off the gas to the appliance in the case when the pilot may go out.

Should a hot water heater be on pilot or on?

That means for normal function it should be set to "On" so the pilot is burning and the water is heating.

Why does my water heater make a loud sound when igniting?

Similar to the explanation of sediment build-up, the gas builds up. If the spark is finally able to ignite and there is excess gas in the chamber, you will hear a loud sound (possibly a gunshot-like sound).

Can gas leak smell come and go?

Natural gas leaks are particularly likely to cause smells in small, enclosed areas where gas can build up. If the leak is outside, the smell may seem to come and go as the breeze blows it away. The other big sign to look out for is a strange noise.

Will a carbon monoxide detector detect a gas leak?

No, carbon monoxide (CO) alarms cannot detect natural gas leaks. They are designed to detect the presence of carbon monoxide, a poisonous gas formed during incomplete combustion of fuels like oil, gas, propane, and wood.

How long does it take for a gas leak to harm you?

Severe leaks can cause this problem in just five minutes. The EPA states that exposure to concentrations of nine ppm or more for eight hours is enough to produce harmful health effects for at-risk individuals. Exit the property and call 911 if you suspect your home has a gas leak.

Can you stay in a house with a gas leak?

Here's what you should DO if you smell gas: DO leave the home, building, or area of the suspected leak. Get to a safe area as quickly as possible. After leaving your home, DO call the 24-hour emergency number for Peoples at 1-800-400-4271, or call your local emergency response number.

What smell can be mistaken for gas?

Hydrogen Sulfide

The gas has a strong scent of rotten eggs, which makes it distinct from other, similar gases. If you detect this rotten egg scent and you are using hydrogen sulfide at your facility, this could be evidence of a leak.

Can a very small gas leak make you sick?

Can a slow gas leak make you sick? Yes, a slow gas leak can cause chronic health conditions, including respiratory problems and lethargy or fatigue.

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