Why Your Furnace Pilot Light Keeps Going Out in San Marcos, TX

A furnace lasts longer than a heat pump because it runs only part of the year, with a service life of 15 to 20 years. But, like any appliance, your furnace can experience early damage if you skip yearly maintenance. One of the initial signs of damage is when the furnace pilot light keeps going out.

This seems like a small problem, but it can lead to the furnace failing. So when you need your furnace the most, especially in January when it gets chilly and occasionally snows, you will get a broken unit. Let’s break down the reasons why the pilot light keeps going out and offer insights on how to fix the problem. 

What Is a Pilot Light, and How Does It Work?

In gas-powered furnaces, the pilot light is a continuous, small flame that serves as the ignition source for the main burners. When you turn on the furnace, gas is released and ignited by this pilot flame, generating the heat your home needs. The pilot light must remain lit for the furnace to operate properly. If it goes out, you must have furnace ignition problems, so it can’t generate heat, leaving your home cold.

How to Tell If the Pilot Light Is Working Properly

A working pilot light should burn with a steady blue flame. If it’s yellow or flickering, this could indicate an issue with airflow or gas supply. Here’s a simple way to check if your pilot light is working as it should:

• Flame Color: A blue flame is ideal. Yellow or red flames suggest a problem with combustion or airflow.
• Consistency of Flame: The flame should burn steadily. Flickering or wavering may point to issues such as a dirty thermocouple.
• Strength of the Flame: If the flame is weak, it could mean insufficient gas flow or poor ventilation around the pilot light.

Common Causes of Furnace Pilot Light Keeps Going Out

There are a number of common causes for a furnace pilot light going out, ranging from simple maintenance issues to more complex mechanical failures. Knowing these reasons can help you pinpoint the problem and take the necessary steps to fix it.

1. Dirty or Blocked Pilot Orifice

A dirty pilot orifice is one of the reasons why your furnace’s pilot light won’t stay lit. Over time, dust, debris, and soot can build up in the pilot orifice, which reduces the flame’s strength. When the flame becomes weak, it’s more likely to go out. Cleaning the pilot orifice is a relatively simple fix, but if you’re unsure, it’s always best to call a professional for help.

2. Faulty or Dirty Thermocouple

The thermocouple is a safety feature that indicates whether the pilot light is on. If it fails to detect the flame, it shuts off the gas supply immediately to prevent a potential gas leak. If your pilot light keeps going out, it could be due to a malfunctioning thermocouple. A dirty thermocouple can’t sense the flame properly, leading to a shutoff of the gas supply. Cleaning or replacing the thermocouple will likely resolve the issue.

3. Poor Ventilation or Airflow

Airflow is critical for proper combustion in your furnace. If there’s a draft near the pilot light, it can blow out the flame. Issues with venting, such as blocked ducts or improper furnace venting, can also contribute to poor airflow and cause the pilot light to go out. Check for drafts around the furnace or any blockages in the ventilation system. Addressing these gas furnace pilot issues could prevent your pilot light from being extinguished prematurely.

4. Gas Supply Problems

A weak or inconsistent gas supply can also be a reason behind a furnace pilot light that keeps going out. If your gas supply is disrupted, whether due to a faulty gas valve, low gas pressure, or an issue with the gas line, the light won’t stay lit. If multiple gas appliances are also having issues, it may be time to contact your gas utility provider to check for broader supply issues.

5. Cracked Heat Exchanger

A cracked heat exchanger is a major issue that can also cause your furnace pilot light to go out. When the heat exchanger cracks, it can disrupt airflow and cause the pilot light to extinguish. If you suspect a cracked heat exchanger, this is a job that should be left to heating services in San Marcos, TX. Continuing to use your furnace with a damaged heat exchanger can be hazardous and lead to further damage to the system.

Troubleshooting Furnace Pilot Light Issues

If your furnace’s pilot light won’t stay lit, there is a furnace troubleshooting guide you can take before calling in a professional. Here’s what you should check:

• Inspect the Pilot Orifice: If there’s dirt or soot blocking the orifice, clean it carefully. Be sure to turn off the gas supply before cleaning.
• Examine the Thermocouple: Clean or replace the thermocouple if it’s dirty or malfunctioning. You can use a fine abrasive material, like sandpaper, to clean it gently.
• Check for Drafts: Be sure that there are no drafts around the furnace that could extinguish the pilot light. Sealing gaps or adjusting the venting system can help.
• Test the Gas Supply: If the gas isn’t reaching the pilot light, check for blockages in the gas line or malfunctioning gas valves.
• Consult a Professional: If you’re unable to fix the problem or suspect a cracked heat exchanger, contact furnace repair services in San Marcos, TX to inspect and repair the furnace.

Conclusion

When your furnace’s pilot light keeps going out, it can be caused by multiple factors, ranging from dirty components to gas supply issues. By addressing these common causes, you can troubleshoot the problem and either fix it yourself or call a professional for help. Remember, if you’re unsure about any repairs or suspect a more serious issue like a cracked heat exchanger, it’s always best to consult with an HVAC professional.

In San Marcos, TX, you can count on Woods Comfort Systems to keep your system running efficiently. For years, our HVAC and plumbing company has been keeping San Marcos’s residents’ furnaces running smoothly so they can enjoy the winters as they should. With our 24/7 affordable services, don’t let a malfunctioning pilot light leave you in the cold.

Call (512) 883-4440 or schedule online to get your furnace up and running today!

Frequently Asked Questions (FAQs)

1. Why does my furnace pilot light keep going out?

The most common reason is a dirty or blocked pilot orifice, which weakens the flame. Other causes include a faulty thermocouple, poor airflow, or gas supply issues. Cleaning the components or calling a professional can resolve the problem.

2. How do I know if my furnace pilot light is working?

A properly working pilot light should burn with a steady blue flame. If it’s yellow or flickering, it indicates a problem with airflow or combustion. A clean and strong flame means it’s working as it should.

3. Can a dirty thermocouple cause the pilot light to go out?

Yes, a dirty or faulty thermocouple can cause the pilot light to go out. The thermocouple senses the flame and shuts off the gas supply if it’s not working properly. Cleaning or replacing the thermocouple can fix this issue.

4. What should I do if my furnace pilot light won’t stay lit?

If the pilot light won’t stay lit, check for dirt in the pilot tube, a weak gas supply, or a faulty thermocouple. You may need to clean or replace these components. If the issue persists, call a professional for a thorough inspection.

5. How can I prevent my furnace pilot light from going out?

Regularly clean the pilot orifice and thermocouple to keep them free of dirt and debris. Ensure good airflow around the furnace and check the gas supply. Scheduling regular furnace maintenance can also help prevent future issues.