How Can I Tell if My Pellet Stove Is Leaking?

Bag of pellets

The bane of every pellet stove owner is when the stove becomes older, when there are parts that no longer work as well as they should when there are several things that need to be fixed. Knowing when this time comes and what to do to track down where the leak is, is a question that needs to be answered. How do you tell where your pellet stove is leaking CO2 into your home, or even worse, where it is leaking soot into the home?

While pellet stoves do burn significantly cleaner than almost all other fuel-burning stoves, there is still a significant amount of soot produced. The outside of your pellet stove will have a build-up of soot around the leak. If you are still unable to find the leak, wait until night and shine a bright flashlight through the stove. You will see the light shining through any slits or holes that the pellet stove or vent system has. 

You might not even know that your pellet stove has a leak, and most people will continue to use their stove even if half the soot is coming up the inside walls. Understanding, stopping, and knowing why leaks form in pellet stoves are vital. Several steps need to be taken to fix a leak, as not stopping one can cause the death of most people inside the house. 

What are the first signs you should be looking for?

You will usually see signs of soot leaking through the holes that have started to develop in your pellet stove, with some stoves that are burning richer releasing a strong smell of smoke throughout the room. Once you notice the strong smell of smoke or see soot leaking and leaving trails from the vents of your stove, you must start working to trace the exact locations. 

Before doing the first burn, many pellet stove owners will use a flashlight shined up through the vents to see any light shining through the pellet stove. This is done to find any leaks that your pellet stove may have as the light travels in the same way that the gases will. Further, in a darkened room, it is always easier to see the light trails made by the flashlight than anything else.

Once you do find the leaks fixing the stove can be a lot harder than just finding the holes or leaks, there are several ways that you need to know about, and each one should be tailored to the leak type. A large majority of people prefer to find the leaks and allow some natural flexing and soot build-up to close the leaks. 

Can you get carbon monoxide poisoning from a leak?

Owing to the types of gases that are created by burning pellets, any leaks can cause severe CO2 poisoning if not treated on time. As the soot leaks out of the stove and vents, so too will the CO2 gases that can be extremely dangerous to people. A majority of people that get CO2 poisoning are not aware of the fact and can die while feeling perfectly fine when they go to bed. 

This is one of the main reasons that you should always have a CO2 detector when you have either a gas, pellet, or wood stove in your home. While one placed near the stove is enough to detect most leaks, it is highly advised that you have a CO2 meter next to the stove and one across the room, with a few extra placed in bedrooms throughout the house. 

CO2 is one of the most dangerous gases people can have in their homes and is often overlooked as people assume that it is only natural for the gas to be present. However, it is much more likely to be undetected as CO2 is odorless and colorless, with a large number of people not even being aware that the air they breathe out can cause enough CO2 build-up in a small room to be dangerous. 

What should you do to find the leak?

There are many ways to find the leak in a pellet stove system, and knowing each one can be the difference between days of head-scratching or simply taking five minutes to tape a small leak. Most installers of pellet stoves that have done it several times will know the fastest ways of testing for leaks and the best ways to fix them. Fortunately, most of the ways you can test for a leak require little else than a few tools in your home.

With a majority of pellet stoves being installed by homeowners, you must learn how to thoroughly test everything before starting the pellet stove. Further, doing the tests properly and tracing where a hole in the vents or the stove itself can be vital to increasing the overall quality of the stove. Always remember that pellet stoves, while perfect when everything is sealed, can cause a danger to your life if the vents and stove are not properly sealed. 

Check for spots

This may seem obvious, but there are spots throughout the venting system and pellet stove itself where it has been welded or taped sealed. Each of these locations is usually on the beds of the system and can be the most obvious weak points of the system, where they are leaking gas, soot, and smoke into your room. 

To fix these are fortunately some of the easier things to do, with a lot of vents simply being sealable by using properly rated duct tape. This is not the normal tape that you may use for arts and crafts. Instead, this tape is usually silver and metallic. It is made from thin sheets of metal with an adhesive attached, sealing off any holes that you may find in the pellet stove or its vents. 

Check the seals

When you or the installer are busy venting everything for the pellet stove, there will be points where the vent connects to the stove, the vent connects to the wall, and the vent goes out of the house. Each of these points is a connection point and has specific seals that they use, with several having heat-resistant silicone that they rely on to make complete seals. These can easily be a point of failure on older pellet vents, and checking to see if these are still working properly can be greatly beneficial. 

It is vital that you check these every few years as routine, as the sealant used can deteriorate with age will become hard and flaky. This is why you will see that older stoves have points along with the entire vent system that has streaks of soot all along with them. Many of the vent systems are not always perfect and require regular maintenance.

Clean the Stove

You can usually see where a stove has internal leaks when the stove has been cleaned properly. This is because the soot can help hide certain imperfections that stoves may have. Cleaning the inside of the stove is not recommended as this will use up several rags that you do have. However, doing so will usually reveal any holes that have developed.

You should preferably test this by having bright light shine onto the pellet stove. Any locations of the stove that leak will allow light to leak through. Many pellet stoves do naturally develop some gaps as the materials stretch when heated up and shrink as they are cooled down. 

Use a light

The most common way to find leaks in the venting system or simply the pellet stove itself is by using an extremely bright flashlight on the inside. By darkening the room or waiting until nighttime, you shine the flashlight up through the pellet stove. This then causes light to shine out of any of the leaks that may have formed. 

Sealing these so that no light shines through them will usually cause all of the leaks and holes in the pellet stove system to be fixed. This is the technique that you will find being used by a majority of people around the world when they are building and testing their pellet stoves. 


Finding the leaks of a pellet stove requires nothing but a flashlight and a bit of time, and the leaks are typically easy to fix and can be done with the right kind of tape. You will find that once all the leaks in a pellet stove have been fixed, then the stove will continue working without a challenge for several more years.

However, if you do move the stove regularly, then you will stand the chance of damaging the vents and requiring you to do a lot more repairs quite often. 

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