How Big Should Pilot Lights Be On A Gas Fireplace: 1/2″?

  • A pilot light is a gas flame that serves as an ignition source for powerful gas burners. (Source)
  • The flame should be blue with a yellow tip and cover ½ inch of the end of the thermocouple
  • The burn rate of different fireplaces varies, but standard ones use 600 BTUs per hour
  • Call for professionals if there are any issues with the fireplace that you cannot fix yourself

What comes to your mind at the mention of a fireplace? I bet it’s some wood, warm lights, warm drinks, golden sparks, and romance—a perfect picture of the classic traditional fireplace where friends and family gather on the cold winter days.

How big should pilot lights be on a gas fireplace?

But, the recent technological advancements have made it possible for you to go the electric way of just pressing a button to light your fireplace. If you have seen the traditional versions, you are familiar with the blue-yellow light flame; this is called the pilot light.

So let us understand more about it and how big it should be in this post.

How pilot lights work

The science behind this technology is simple; the pilot provides the flame that ignites the gas from the main burner.

The ignition system heats to a specific temperature that helps activate thermocouple sensors that send signals to the flame and turn on. If the flame goes off, the generated electricity stops, and the valve shuts and cools off rather quickly.

The fireplace has a button you can press for the valve to open to fix that. It takes only 30 seconds for the valve to reheat, and you should keep the button pressed until it reheats. If it doesn’t turn back on, you might as well do it manually or check the system for problems

How big should the pilot light be?

The flame should be blue, with yellow tips and long enough, about ½ inch, to cover the end of the thermocouple tip. The thermocouple sensors should look ‘wrapped’ by the flame.

Its size shouldn’t be too long to reach sensors well, but if they are shorter, you can correct it. Whereas it is easy to fix this problem, I would advise you to consult an expert on the issue if you are unsure of it. If the flame stands like a candle, your system could have problems.

Common pilot light problems and how to fix them

You should know how the light should be to examine the ignition system. Some of the issues you could encounter include:

i. A high flame and a bright orange color

The bright orange color won’t heat the thermocouple sensors well, making it challenging to achieve the needed temperatures for the sensors to work. Adjust the screw on the fireplace clockwise with a screwdriver to correct that. Some fireplaces might have a button you can press for adjustments.

If none of the above works, there could be debris to be cleaned at the assembly. Professionals best do the cleaning task, but you could do it yourself. To do that, unscrew the pilot orifice and pilot tube and try cleaning any obstructions with a brush or even replace it with a new one.

ii. A low flame

The performance of a flame is affected if the burner is clogged or faulty. Other possible reasons are gas residues and carbon buildup. These mishaps lead to premature failure of the burner, but they can be fixed by cleaning the burner. If it doesn’t help, replace the burner with a new one.

iii. Going out

Sometimes, the ignition systems might be superb, but your light may go off. There could be a problem with the oxygen supply in venting in such cases. Venting should provide enough oxygen for better performance.

Another possible reason could be the gas availability on the regulator or even a possible airflow from a nearby window or door.

iv. Noise

You might hear roaring or rumbling sounds. The roaring sound means the flame needs some adjustments. On the other hand, rumbling sounds indicate it is time to clean the burners.

v. Strange odor

If there’s any strange odor, clean and remove any obstructions on the chimney, and clean the flue. If the smell is close to burning wire or a rotten egg, shut off the fireplace and seek consultation from a professional.

vi. No ignition

The flame might refuse to ignite and if it happens, open the gas valve to restore flow and check that it operates properly. Tripped breakers could also be a possible reason there is no ignition. Just check the circuit breaker box and reset the breakers.

Frequently Asked questions

Pilot light is a good source of heating. Some of the frequently asked questions surrounding them include:

1. Should I turn off the gas fireplace during the summer season

Yes. Spiders are attracted to an artificial ingredient added to the gas, and leaving it on would draw spiders into clogging the tubes.

Gas is also costly, and you wouldn’t want to waste it just like that. Summers are also hot, and leaving the fireplace on will add extra heat to your house. The light heats the glass door of the fireplace and makes the temperatures rise.

2. How much can a gas fireplace cost if it is on throughout?

The average usage is between 239BTU and 1706 BTUs per hour which equates to $7-10 per hour. Standards ones use 600 BTU per hour.

3. How do I correctly light gas logs?

Turn the control handle to the pilot position, press it inside, light the pilot with a match, and wait till they burn on their own. You can then set the handle to on. Learn how vent free gas logs work.

4. Should the pilots be on in a gas fireplace?

Depends. Older versions use a continuous pilot light that is usually on throughout. The modern ones are more energy-efficient and are lit only when the fireplace is on.


Now you understand how big a pilot light should be, and I hope you are looking forward to warmer evenings around the fireplace.


Eugene Duke Pic

Hi, my name’s Eugene Duke and I love sitting by my fireplace reading a book and sipping on an adult beverage. Do you have a fireplace in your house? I’ll help you figure out the best type and style of fireplace for your home.


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