Furnace Pilot Light Keeps Going Out

If you rely on a gas furnace for wintertime comfort and your system uses pilot light technology for ignition, there’s a decent chance you’ve experienced situations in the past when you had to relight the pilot. If that routine task has turned into a larger problem because your furnace pilot light keeps going out, there could be some upkeep or mechanical malfunction problem in play.

Cooper’s Plumbing & Air is the leading provider of expert HVAC services in Bainbridge, GA, and we’d like to share some useful information about pilot light problems and how we address them.

What Is a Furnace Pilot Light?

Older gas furnaces use a small flame known as a pilot light to ignite the main burners. During the heating season in Georgia, this flame should remain lit to make sure your furnace is ready to produce heat on demand. But if the light will not remain lit, you’re likely to find yourself dealing with ongoing problems during cold weather with keeping your furnace going.

Common Reasons Why a Furnace Pilot Light Keeps Going Out

These are some of the typical pilot light problems we address during service calls.

1. Thermocouple Malfunction

The thermocouple is a safety device that shuts off the gas supply if it fails to detect the pilot flame. This component can malfunction when misaligned or dirty, leading to an improper signal that extinguishes the pilot light.

An HVAC technician will check the thermocouple alignment within the flame. If it’s properly positioned, they will clean off soot or corrosion using fine-grit sandpaper. If cleaning doesn’t restore function, they test voltage output with a multimeter to determine whether they should replace the part.

2. Gas Valve Issue

Gas valve issues disrupt fuel supply and can prevent the pilot light from staying lit. Over time, valves can wear out, clog, or fail to regulate pressure properly.

A technician will assess gas pressure using a manometer and ensure no external gas supply issues exist. If the valve is partially clogged or malfunctioning, they clean or replace it. After installation, they test the ignition and adjust the pressure for consistent performance.

3. Furnace Flame Sensor Issues

Furnace flame sensors detect burner ignition in modern furnaces. If the sensor becomes blocked by carbon buildup, it will likely fail to recognize the flame and shut off the gas supply.

A technician will remove and inspect the sensor, carefully cleaning it with an abrasive pad to restore conductivity. If corrosion is severe or conductivity remains low, they will replace the sensor to ensure proper flame detection.

4. Draft Inducer Problems

Draft inducers force oxygen toward the burners to support combustion. When they malfunction, the resulting negative pressure disrupts airflow in the furnace — a common reason a furnace pilot light keeps going out.

A technician inspects the venting system for blockages like debris or ice and clears obstructions. If the draft inducer motor is noisy or unresponsive, they test electrical connections and replace the motor if necessary to ensure proper circulation and stable combustion.

5. Flame Rollout Switch Activation

The flame rollout switch shuts down the furnace if flames escape the burner chamber. That problem often comes from restricted exhaust airflow or a cracked heat exchanger.

A technician checks for heat exchanger cracks and blocked vents. When needed, they clear obstructions or recommend heat exchanger replacement. After resetting or replacing the switch, they run a combustion test to verify safe operation.

6. Clogged Burner Ports

Clogged burner ports impede gas flow. That leads to weak flames that fail to sustain the pilot light.

A technician inspects the burner assembly, cleaning ports with a wire brush or compressed air. If corrosion is severe, they can replace the burners.

Preventing Ongoing Pilot Light Issues

Minimize the risk that your furnace pilot light keeps going out with these preventive measures:

Schedule annual furnace maintenance to ensure all components are clean and functioning properly.
Keep the area around your furnace free from drafts.
Replace worn-out parts like the thermocouple or flame sensor when your HVAC system professional recommends it.
Always ensure proper gas flow by checking for visible damage to the unit’s gas line or valve.

FAQs About Furnace Pilot Light Issues

These are some common questions we encounter when servicing gas furnaces.

How Can I Tell if My Pilot Light Is Out?

If your furnace stops producing heat, check to see if your pilot light is out by looking for a small blue flame near the gas burner. If the flame is missing or weak, you may also hear a clicking sound as the furnace attempts to ignite.

What Color Should My Pilot Light Be?

The color of your pilot light should be a steady blue. If the flame flickers or is yellow or orange, that’s a sign of improper combustion, a dirty burner, or gas mixture issues that an HVAC system professional should inspect.

Can a Dirty Air Filter Affect My Pilot Light?

A dirty or clogged air filter can affect your pilot light by impairing airflow. That can lead to overheating which triggers safety mechanisms that shut off the gas supply and extinguish the pilot light.

Count On Cooper’s Plumbing & Air in Bainbridge, Georgia

If you’ve had to deal with situations where your furnace pilot light keeps going out, don’t wait for an extreme cold snap to take action. Call on the friendly experts at Cooper’s Plumbing & Air to quickly diagnose and repair any HVAC system problems, including a furnace that’s blowing cold air.

Why Your Furnace Pilot Light Keeps Going Out