The Furnace Pilot Light Keeps Going Out
Lighting then relighting the pilot light on your furnace is a nuisance. Here are common reasons why it could be going out and steps you can take when it happens.
What is a Pilot Light
The pilot light is a small flame inside the combustion chamber of a gas-fueled furnace. When operating correctly, it stays lit thanks to a constant flow of gas from the gas valve. It ignites the burners when the thermostat tells the furnace to begin producing heat.
Reasons Pilot Light Keeps Going Out
Pilot Light is Dirty
The flame sits in a small opening, also called the pilot orifice. Because the opening is always exposed, it can slowly collect dirt, dust, soot, ash, and other tiny debris particles. As these build, they hinder the gas flow from reaching the flame, causing it to extinguish.
Thermocouple Fails (broken, dirty, off center)
Every furnace has a thermocouple, a thin copper rod located next to the pilot light. The flame encircles the thermocouple and heat from the flame produces enough voltage in the rod to open the gas valve. But, it can fail for one of these reasons:
- Broken or burned out: The thermocouple expands and contracts when it heats then cools. This constant cycle eventually wears the metal enough that it breaks or burns out.
- Dirty: Like the pilot opening, the thermocouple may become coated in tiny particles, such as dirt or ash, and not be able to properly sense the pilot light.
- Off-center: We’ve talked about how it’s important for the pilot light to fully encircle the thermocouple. If it’s bent or off-center, the indirect contact won’t be enough for the thermocouple to work as it should.
Drafty Basement or Attic
Two of the draftiest rooms in a home often house the furnace. That’s why one of the first things to do when the pilot light keeps going out is to check for air currents around the unit. If you find an air leak, patch or repair it as soon as possible.
How to Re-Light Pilot Light
Check the Manual
Although most pilot lights can be relit with the same steps, it’s best to reference the owners’ manual for your specific make and model of furnace. If a physical copy of the manual is unavailable, check the manufacturer’s website.
Turn off the Gas
Turn off gas to the furnace then disconnect the unit’s power source. Then wait at least five minutes for the remaining gas in the line and valve to dissipate.
Reset the Gas and Light the Pilot Light
Turn on the gas again then move the dial at the bottom of the furnace to the pilot setting. Gas should resume flowing to the pilot opening. Then, press and hold the reset button while using a long lighter to relight the flame. Release the button when the pilot flame catches.
Pilot Light Safety and Maintenance Tips
Schedule Routine Tune-Ups and Maintenance
Routine furnace maintenance is the best way to keep your unit operating efficiently and staying ahead of potential issues. This checkup is usually scheduled before the furnace is needed during the colder months. Along with efficiency in mind, an HVAC technician makes sure the system is safe for operation, and methodically goes through a checklist with items such as:
- Looking at the vent system then removing debris and making repairs if necessary;
- Checking the heat exchanger for damage — the heat exchanger is where carbon monoxide forms;
- Making sure the electrical connections work properly; and
- Checking and testing all safety controls and sensors for proper function.
Make sure to Change Your Air Filter
Changing the air filter every two to three months helps your furnace produce optimal heat and improves the indoor air quality. A clogged filter blocks the necessary amount of air flowing into the furnace, affecting the amount of heat being produced.
Place Carbon Monoxide Detectors in Bedrooms
Because carbon monoxide (CO) is a byproduct of the combustion process, it’s critical you keep working CO detectors in your home, especially bedrooms. A toxic leak can develop as the furnace ages, or if it hasn’t proper furnace maintenance; the detectors alert people in the home before the CO levels rise to dangerous or even deadly levels.
If any detectors go off, leave the home and call 911 immediately from a safe location.
When all internal components are maintained and working, the pilot light will help your furnace produce heat on the coldest of days. Need your furnace checked? Call Proskill today.