Thermacell Not Lighting: 3 Easy Ways to Fix

Thermacell is a must-have device to repel all biting insects. If you are a person who loves camping outdoors, a thermacell is surely something you depend on. 

But suddenly in the middle of nowhere, your thermacell not lighting can be a hassle. So what should you do in this situation?

First of all, check if there is enough fuel. If not you have to replace the fuel container with a refill. Also, make sure that the mat is new. You have to keep the device clean and dry for it to function properly.

Now, all this might sound confusing all at once. For that, we have discussed everything in detail for you in the next section below.

Reasons and Solution

Firstly, your thermacell not lighting means that it is not functioning. This might be due to several reasons. Your fuel might be empty and you need to replace the repellant mat. 

The solutions including the steps to do them are given below:

Reason 1: Empty Fuel Cartridge

A thermacell fuel usually lasts for about 10-12 hours of continuous use. Soon after that, the orange light will turn off. This is an indicator that the gas fuel needs to be replaced. 

Usually, the refill comes in two sizes. As claimed, they give 12 hours and 40 hours of protection. Even though the hourly use is limited, the fuel refills can be used multiple times.

Solution 1: Replace the Fuel

Often, even if there is liquid remaining in the refill, the light might be off. This happens as the device is not providing reliable protection even though there is liquid remaining inside. t’s an indication of replacing the refill.

The steps of fuel replacement of your thermacell are given below:

Step 1 of 4: Open the Thermacell

At first, remove the Thermacell device cover. It is located on the side of the device farthest from the black grill. In most models, the cover is placed on the handle of the device.

As you open the cover, a socket for the butane cartridge ( fuel refill) will be visible.

Step 2 of 4: Replace the Cartridge

You have to remove the old refill and place the new one. Now, open the cap from a new butane cartridge and place it in the socket. Here is a list of the ones you can use for the best results.

To fix the cartridge in place, turn it clockwise inside the thread.

Step 3 of 4: Reassemble the Parts

Place the Thermacell device cover to its original position. You have to turn the device on by moving the switch beneath the black grill. This will turn on the gas ignition.

After about 5 to 10 seconds,  press the “Start” button. This button is next to the on/off switch, below the black grill. But in some models, you need to twist a knob to turn the device on.

Step 4 of 4: See if the Light is Glowing

You will see an orange light glowing on the top of the device. This will indicate that the thermacell is heating up and your problem is solved.

Reason 2: Jammed Thermacell

Often a thermacell doesn’t turn on in humid weather or rainy weather. In such weather, it takes time to start the device. It is even mentioned on the device to keep it strictly at a dry and normal temperature. 

Again, your thermacell might get jammed due to debris and waste. For this reason, the grill might get clustered resulting in the light not glowing. 

Solution 2: Clean the Thermacell

In such cases, you can clean the thermacell and reset the fuel and mat. Firstly, open the Thermacell with all the steps mentioned in solution 1. 

Now with a damp cleaning mat, you can clean the inner part of the device. Don’t forget the grill and inside the chamber. 

We would also recommend you to put a few drops of oil like the all-purpose oil. Put a few drops inside the ignitor once taken apart. There is also a small spring inside the ignitor and plunger in the gas tensioner. 

You can have them exposed with the help of a small screwdriver of the right size. Put oil into the springs to make them work well. Also, be careful not to lose these parts. It is difficult to get them in the right size.

After cleaning all the pipes and hoses, remove the debris. Thermacell is often used outdoors for protecting you from all insect bites. So, you also need to check if there are insects or water inside the device. They might as well be trapping the device from functioning properly.

If you are a traveler, there are other things you might be considering choosing like a steripen or a filter.

Reason 3: Repellent Mat Turning White

Just like the Fuel refill, you also need to change the mat when it turns white. You need to replace the mat in such cases. Replaceable mats are available in the market. 

Here are some of the best ones you can choose from:

Solution 3: Replace the Mats

The repellant mat turns white after 4 to 5 hours of continuous use and needs to be replaced. All you need to do is remove the old mat and replace it with a new one. 

Many times, you might see that the used mat has turned brown at the top. There’s nothing to be anxious about here. It’s completely natural.

Turn on the gas and let it run for a few minutes once the mat has been replaced. Then repeatedly hit the start button. You will notice that the light is now turned on.

Thermacell Still Not Lighting?

Your thermacell light might not be working correctly even for lesser gas pressure. Both the gasoline refill and the mat must be replaced in this scenario. Check to see if the engine is running by switching it on and paying attention to it.

Turn on the start button and see if the light is on after around 5 minutes. If it still doesn’t function, push the start button a few more times.

Is your thermacell light still not functioning correctly? Then there’s a chance there’s an issue with the wiring. For this case, you can email the official thermacell website about your problem. They will replace it in time.


What does the red light on thermacell mean?

The red light is a warning that comes if the battery level is low. The red light turns on when the battery is about 20 minutes left. When the device is warming up, an orange light flashes in the circle. But it varies between models.

How long does it take for the thermacell to start functioning?

A thermacell usually takes about 10-15 minutes to start functioning effectively. But this time might vary depending on the model and weather. The protection is for about 25 feet and is approximately 98 percent effective. 

Is Thermacell safe for animals?

Yes, thermacell is fully safe for all animals including dogs. It repels all kinds of mosquitoes including biting insects. It creates a shield making a bug-free comfort zone.


That is all from us on thermacell, not lighting. A thermacell repeller covers about 225 square feet of area. If you ask us, it’s a good investment.

Before we end, here is an additional tip for you. You can use a cover on your thermacell if you’re camping outside. It will protect the device from getting damaged and will last longer.

That is it until next time. Till then stay safe and have a good day!