Why Does My Water Heater Pilot Light Keep Going Out?

If your gas water heater's pilot light keeps going out, something is preventing the pilot flame from staying lit or causing the water heater's safety system to shut off the gas supply.

Common causes include a dirty pilot assembly, problems with the thermocouple or thermopile, inadequate combustion air, a faulty gas control valve, or a problem with the water heater's venting.

If you can relight the pilot according to the manufacturer's instructions but it repeatedly goes out, that's a sign the water heater should be inspected rather than continually relit.

Here's what could be happening.

1. The Thermocouple or Flame-Sensing System Isn't Working Properly

One of the first things to consider is the water heater's flame-safety system.

Many gas water heaters use a thermocouple, thermopile, or another flame-sensing device to confirm that the pilot flame is actually burning.

If the system doesn't detect a proper flame, it shuts off the gas supply as a safety measure.

That means you may be able to light the pilot, only to have it go out again shortly afterward.

Signs this could be the problem:

• The pilot lights but won't stay lit

• The flame goes out when you release the pilot control

• You repeatedly have to relight the water heater

• The burner won't ignite even after the pilot has been lit

The exact components vary by water-heater model, so diagnosing the cause may require professional testing.

2. The Pilot Assembly Is Dirty or Partially Blocked

A pilot flame needs a consistent supply of gas and air to burn properly.

Dust, debris, or buildup around the pilot assembly can interfere with the flame.

Instead of a strong, steady flame, you may notice a pilot that appears weak, irregular, or has difficulty staying lit.

Because the pilot assembly is part of the gas system, don't attempt to disassemble or modify it unless you're qualified to work on gas appliances.

3. The Water Heater Isn't Getting Enough Combustion Air

Gas water heaters need air for combustion.

If the water heater is installed in an enclosed or poorly ventilated area, inadequate airflow can interfere with proper operation.

Problems can also occur if combustion-air openings become obstructed.

Modern water heaters may contain additional safety systems designed to shut the unit down when unsafe combustion conditions are detected.

If your pilot-light problem began after objects were placed around the water heater or changes were made to the room where it's installed, airflow is worth considering.

Never block vents or combustion-air openings around a gas water heater.

4. There Could Be a Venting Problem

Your water heater doesn't just need air coming in. Combustion gases also need to vent safely out of the home.

A venting or draft problem can affect water-heater operation and, more importantly, can create a carbon monoxide hazard.

Potential warning signs include:

• Pilot or burner problems

• Soot around the water heater

• Unusual odors

• Visible problems with the vent connection

• A carbon monoxide alarm activating

If you suspect a venting or carbon monoxide problem, don't continue trying to operate the water heater.

If a carbon monoxide alarm sounds or anyone experiences possible carbon monoxide poisoning symptoms, leave the home and contact emergency services or your gas utility from a safe location.

5. The Gas Control Valve Could Be Failing

The gas control valve regulates gas flow to the pilot and burner.

If the control isn't operating correctly, the pilot may fail to stay lit even when the pilot assembly itself is functioning normally.

A gas control problem requires proper diagnosis. This isn't a component homeowners should attempt to bypass or modify.

6. A Safety Switch May Be Shutting the Water Heater Down

Depending on the model, a modern gas water heater may have additional safety devices that can shut down operation when the unit detects a problem.

That's important because a pilot that won't stay lit isn't always simply a "bad pilot."

The water heater may be doing exactly what it was designed to do: shutting itself down because it detects an unsafe operating condition.

That's one reason repeatedly relighting a pilot without finding out why it keeps going out isn't a good long-term solution.

7. The Water Heater May Be Getting Older

Sometimes a recurring pilot problem is one symptom of an aging water heater.

That doesn't automatically mean you need a new one.

A repair may make sense if the problem involves a serviceable component and the rest of the water heater is in good condition.

However, if the unit is older and experiencing multiple problems, it may be worth comparing the cost of repair with replacement.

Why Does My Pilot Light Go Out Right After I Light It?

If your pilot lights but goes out as soon as you release the control, the flame-sensing safety system may not be detecting the pilot correctly.

That could be related to the pilot flame itself, the thermocouple or other flame-sensing components, or another part of the gas-control system.

Follow the lighting procedure printed on your water heater or provided by the manufacturer. If the pilot still won't remain lit, it's time to have the problem diagnosed.

Why Does My Water Heater Pilot Light Keep Going Out Overnight?

A pilot that stays lit for hours and then goes out can be particularly frustrating.

Intermittent problems can have several causes, including inconsistent pilot operation, combustion-air problems, venting or draft conditions, or a component beginning to fail.

The timing alone usually isn't enough to identify the problem.

If it happens repeatedly, an inspection can help determine why the water heater is shutting down instead of simply relighting it every morning.

Is It Dangerous If My Water Heater Pilot Light Keeps Going Out?

A pilot light going out isn't automatically an emergency, but repeatedly losing the pilot shouldn't be ignored.

Gas water heaters contain safety systems designed to stop gas flow when a flame isn't detected.

However, because recurring pilot problems can sometimes involve combustion, venting, or gas-control issues, it's important to determine the cause.

If You Smell Gas

Do not try to relight the water heater.

Avoid flames, switches, or anything that could create a spark. Leave the area and follow your gas utility's emergency instructions from a safe location.

Can I Relight My Water Heater Pilot Light Myself?

Many water heaters provide manufacturer instructions for relighting the pilot, and homeowners may be able to follow those instructions safely.

Always use the instructions printed on your specific water heater or provided by its manufacturer.

Don't improvise a lighting procedure based on instructions for a different model.

And there's an important distinction:

A pilot that went out once may simply need to be relit. A pilot that keeps going out needs a diagnosis.

If you've followed the correct procedure and it won't stay lit, don't keep repeatedly attempting to restart it.

Should I Repair or Replace a Water Heater With Pilot-Light Problems?

A pilot-light problem doesn't automatically mean you need a new water heater.

The decision depends on:

• The age of the water heater

• The actual cause of the problem

• The condition of the tank

• Whether other components are failing

• The cost and practicality of the repair

A relatively simple problem on an otherwise healthy water heater may be worth repairing.

An older water heater experiencing recurring problems may make replacement the more practical choice.

Water Heater Pilot Light Won't Stay Lit in Kansas City?

If your water heater pilot light keeps going out, Hot Water Biz can help identify what's causing the problem and determine whether repair or replacement makes sense.

Hot Water Biz specializes in water heaters and serves homeowners in Belton, Raymore, Peculiar, Harrisonville, Cass County, and the surrounding Kansas City area.

Instead of repeatedly relighting a pilot that won't stay lit, have the underlying problem checked.

Contact Hot Water Biz for water heater service in the Kansas City area.

Frequently Asked Questions

What is the most common reason a water heater pilot won't stay lit?

Problems with the pilot flame or flame-sensing safety system are common possibilities, but there are several potential causes. A technician may need to inspect the water heater to determine exactly why the pilot won't remain lit.

Can a dirty pilot cause the flame to go out?

Yes. Debris or buildup that interferes with the pilot flame can cause operating problems.

Can a bad thermocouple cause the pilot light to go out?

Yes. On water heaters that use a thermocouple, a problem with the thermocouple can prevent the gas control from receiving the signal that a pilot flame is present.

Why does my pilot light keep going out after I relight it?

The water heater may have a problem with the pilot assembly, flame-sensing system, combustion air, venting, gas control, or another safety component. Repeatedly relighting it doesn't address the underlying cause.

Does a pilot light going out mean I need a new water heater?

Not necessarily. Some pilot-light problems can be repaired. The age and overall condition of the water heater should also be considered before deciding between repair and replacement.

Should I call someone if my pilot light keeps going out?

Yes. If you've followed your water heater manufacturer's lighting instructions and the pilot repeatedly goes out, having the unit inspected is safer than continually relighting it.