Why Is My Pilot Light Flame Too High?

There are many things you need to look out for when it comes to keeping a healthy pilot light flame. Ignoring issues or flame conditions can lead to some serious and often dangerous situations for your home. A couple of things could be a pilot flame being too high or the flames burning a yellow color as opposed to the natural blue tone.

In this article, we will look at key issues to look out for and advise on how to maintain and monitor your pilot flame light.

If you find your pilot flame is too high, then this could be because of high gas pressure.

High gas pressures can harm your system. It can increase the risk of overheating which can lead to the internal components becoming damaged. Therefore, it is important to get this checked out and have your gas pressure tested and adjusted regularly.

How a Pilot Light Works

The main purpose of the pilot light is to provide a flame for the main burner system. Therefore, when the furnace is turned on, a valve will release gas in the burner and then the pilot light will ignite that gas.

The pilot light is made by emitting a small quantity of gas through a small gas pipe tubing. Then the gas coming out from that small tube is then lit and remains lit.

What should a Pilot Light Flame Look Like?

The normal color your pilot light should be is deep blue, meaning it’s getting enough oxygen. It also needs to strong enough that it can cover half an inch of the thermocouple tip.

When oxygen is restricted the flame will transform into a yellow color, with a lazy flicker.

The thermocouple is a very important safety component that works with the pilot light. If the pilot light is out, then the thermocouple will detect this and shut off the gas valve for the pilot.

The pilot flame must touch the thermocouple at a specific level. Now, if you notice that the flame is still blue but weak and barely touching the thermocouple, then it means it needs to be adjusted to be stronger.

However, if the pilot light flame is extended way over the level then it means it is too strong, which could be due to irregular gas pressures.

One of the main reasons why pilot light flames burn a yellow color is because the air coming from the valve for air intake is probably dirty and clogged. A dirty valve can cause the air to become blocked and cause incomplete combustion which will lead to the yellow color.

If there is only a small amount of dirt obstructing the area, then the yellow color will only be visible on the tip of the flame.

A yellow pilot light can cause two issues, one of them will that your pilot light will go out more frequently which will need relighting more often. This is because the yellow flame is not as hot as the blue flame and so it won’t heat the thermocouple causing the gas to supply to the pilot light being shut off.

The second issue with a yellow pilot light is that carbon monoxide could potentially leak out into your home. The lazier flame of the pilot light will not be able to burn the carbon monoxide completely and so gas can escape out.

Reasons your Pilot Light Flame is too High

We mentioned before that the reason the pilot light flame is too high could be due to the high gas pressure in the system.

It is important to regulated gas pressures as this will affect the pilot flame and the burner system. The valve in your gas furnace regulates the system to ensure that there’s enough to properly help it function correctly. It is important to keep an eye on gas pressure because once it starts to fluctuate then you could end up with some problems.

High gas pressure can cause the pilot light flame which can be bad for your furnace. It can increase the risks of overheating and potentially damage the components inside. It is important to get your gas pressure tested and adjust regularly.

How to Inspect the Pilot Light Flame

Now the color of the pilot light flame will vary depending on whether you use propane or natural gas. Natural gas will generate a bright blue light with the tip being yellow, whiles propane flames have a blue-green hue with a yellow tip.

Here’s a process on how to inspect your pilot light flame:

  • Take off the cover of the furnace panel which should reveal the burner assembly and the pilot. You should be able to view the pilot flame upon opening.
  • If you discover the pilot light is out then try to relight the flame.
  • If you notice that the pilot light is not lighting or struggles to stay lit, then you need to replace the thermocouple.
  • Now, you’ll see the flame of the pilot light and you’ll be able to examine it well. It should be a healthy blue color with the tips yellow, and it should be covering half an inch of the thermocouple tip.
  • Now, if you notice the flame is too strong and not adjusted properly, it is blue and noisy which can cause the furnace to function improperly.
  • Now if you see that the pilot flame is burning a weak and yellow color, then it will not heat the thermocouple enough to keep the gas valve open.

How to Adjust a Pilot Light Flame

If you want to adjust the flame of the pilot light then this Is possible by using a small screw on the pilot valve.

Note, that you might want to check the manual to ensure you are doing it correctly.

  • Find the open-up access plate at the front of the furnace which will give you visibility and access to the flame.
  • Check the flame. Now if you notice that it’s small and flickers on/off then you will need to adjust the size of it by using the screw you’ll see on the pilot light.
  • Now, once you have located the screw, turn it counter-clockwise and the flame should get bigger.
  • Now if you rotate that same screw, then the flame will get smaller. Note that the flame should stay at a consistent height and shouldn’t flicker.
  • Now the flame is at the right height you can place the front of the furnace back.


It is important to monitor the condition of your pilot flame light as it will help you keep your system in good shape.

Keeping an eye on the flame can tell you a lot about the condition and state of your furnace, from too low to too high a flame down to the color.

For example, if your pilot flame is too high then it could be an issue with the gas pressure. Therefore, it is best to check the gas pressure regularly and making adjustments as required to ensure that you keep a healthy gas flow.