What to Do When Your Pilot Light Goes Out

Pilot lights occasionally go out, which isn’t a cause for concern. However, if your pilot light won’t relight, or goes out repeatedly, it may indicate that something is wrong. In this post, we will cover why your pilot light went out, what it might mean, and how to address the problem. 

As a homeowner, knowing how to relight your pilot light is a useful skill to have. It isn’t difficult, and your furnace may actually include instructions (typically printed on the access panel) to guide you. 

However, we always suggest leaving furnace repair, installation, and maintenance issues to the professionals. Without the proper training, you could injure yourself or damage your furnace or your home.

What is the Pilot Light For?

diagram showing the parts of a natural gas furnace

Older furnaces that run on natural gas are usually equipped with a pilot light. The pilot light is a small, blue flame that is used to ignite the natural gas being pumped into the main burner. Whenever your furnace turns on to heat your home gas is released through a valve, where it comes in contact with the pilot light and is ignited, producing heat. 

The pilot light itself is also fueled using natural gas, which it gets from a small tube in your gas pipe. This tube is fitted with a safety valve (the thermocouple), which stops the flow of gas if the pilot light goes out. This prevents gas from building up in your furnace, posing a safety hazard.

Why Would My Pilot Light Go Out?

Your pilot light may go out for several reasons. Some causes can be rectified quickly, while others are a little more involved.

Air Flow Issues

Just like blowing out a candle, a small gust of air can blow out your pilot light. If this is the case, you can either relight your pilot light or call a professional for assistance. This can happen if there is a strong wind, or if one of your furnace ducts is leaking air. 

If your flue or chimney is damaged, wasn’t installed properly, or is not sized correctly to match your furnace’s needs, it can cause a draft or allow wind into your furnace. 

Your Gas Has Been Shut Off

Your pilot light relies on your natural gas to stay aflame, so if your gas is shut off, your pilot light will go out. Simply turn your gas back on and either relight your pilot light yourself or call a professional.

Your Furnace Needs a Cleaning

If the pilot orifice (the small opening in your gas pipe that fuels the pilot light) is dirty, it can affect how well your pilot light burns. If your pilot light continues to go out, it may be that it isn’t able to get enough fuel to sustain itself. Your pilot light should be bright blue, not red or yellow. A red or yellow flame indicates that your pilot light isn’t getting enough fuel.

Cleaning your furnace regularly helps reduce the wear and tear on its components, and can even help you keep your heating bill down. To keep your furnace running at peak efficiency, you should have a professional in for a maintenance appointment and duct cleaning at least once per year.

Your Thermocouple is Loose or Faulty

If your pilot light continues to go out, it may indicate that your thermocouple is either loose or faulty. If this is the case, your thermocouple will need to either be tightened or replaced.

A Temporary Gas Shortage

The issue may not be with your furnace at all. High natural gas demand may stress the supply, leaving a little less to go around. If your furnace isn’t able to get enough natural gas, it can cause your pilot light to go out. If the professional you called can’t find an issue with your furnace, contact your utility company and see if the problem is on their end.

How Can I Restart My Pilot Light?

checking off items on a checklist

If you don’t feel comfortable restarting your pilot light, please don’t hesitate to call an expert for assistance

Step 1: Turn off your furnace. Never adjust anything in or on your furnace while it’s still running. 

Step 2: Locate your gas valve. Most gas valves have three positions: on, off, and pilot. Turn the knob to the “pilot” position.

Step 3: Hold down the red button. The red button should be located near your gas valve. The red button pushes gas to your pilot light. Depending on what style of furnace your pilot light will either be automatic or manual. 

Automatic pilot lights can be re-lit using just the red button, while manual ones will require an external flame source (such as a long match) as well. If you have a manual pilot light, hold your match above the pilot orifice while pressing the red button.

If you don’t have a long-handled match (like the ones designed for lighting barbecues), either use a pair of pliers to hold the match (and keep your hands away from the flame) or call a professional to re-lite your pilot light for you. 

If your furnace is equipped with a manual pilot light, you may need to open a small access panel to reach it. 

Step 4: Light the pilot light. For a manual pilot light, very carefully light the pilot orifice, taking care to keep the red button pushed down. Continue to hold the red button down for 60 seconds.

Step 5: Let go of the button. Carefully let go of the button. Your pilot light should stay lit. If it doesn’t, you may need to call in a professional to assess the situation and find out why it won’t stay lit.

Step 6: Turn your gas back on. Turn the gas valve back to the on position. If you forget to do this, your pilot light won’t stay lit.

Step 7: Turn your furnace back on. If you had to remove or open an access panel to get to your pilot light, make sure you remember to close it.

When Should I Call a Professional?

When in doubt, you should call a professional. Furnaces can leak dangerous gasses, such as carbon monoxide, into your home if maintenance or repair work isn’t done correctly. Not everyone is a trained furnace repair technician, and that’s okay! The experienced team at Mersey Heating & Air Conditioning is here to help you navigate your furnace woes 24 hours a day, 7 days a week, 365 days a year. Call us today. We’re very friendly.