Pellet stoves are increasing in global popularity as a safe and cheaper home heating option. While the low cost of heating with a pellet stove is an obvious plus, the safety question often pops up when homeowners consider pellet stoves as a home heating option. So, how safe is a pellet stove, or can a pellet stove explode?
A pellet stove can explode, but this is rare because they come with several safety features. However, in unusual cases, a pellet stove can explode if it is wrongly installed, is using poor quality pellets, the airway is blocked, the fire setting is low, or maintenance is neglected.
This article discusses the possible causes of pellet stove explosions and how to prevent or resolve them. Read on to gain a better understanding of pellet stove safety.
5 Reasons Why Pellet Stoves Explode and How to Fix Them
According to the US Department of Energy office, pellet stoves are the cleanest solid fuel home heating appliances. They are also safer than other mechanically controlled solid fuel stoves. Pellet stoves have better safety because they are electrically controlled and have several inbuilt safety features.
Despite this, there are recorded stories about pellet stoves malfunctioning and causing explosions. So, why would a pellet stove catch fire or explode?
Here are 5 reasons a pellet stove can explode:
- Incorrect pellet stove installation
- Poor pellet quality and pellet overload
- Lack of pellet stove maintenance
- Blocked pellet stove airway
- Low fire setting
Let’s explore each of these causes in greater detail and discuss solutions in addition to habits you can implement for accident prevention.
1. Incorrect Pellet Stove Installation
Proper installation is the number one precaution against pellet stove explosion. Correct pellet stove installation has to do with two main aspects:
- The accurate placement of pellet stove parts, and
- The observance of the recommended clearance from combustibles.
Here are some tips for ensuring safe and reliable pellet stove installation:
- Pellet stoves should only be installed by professionals. You can use resources like the “Choose An NFI Certified Specialist” feature offered by the National Fireplace Institute to find the right installer for you.
- Follow all the building codes for your area. Additional guidelines in building codes take precedence over pellet stove installation manuals.
- Ensure you follow all the necessary permits and inspection guidelines before installing a pellet stove. This can make accidents less likely, and increase your chances of reliable installation.
- Meticulously follow the “clearance from combustibles” guidelines included in your pellet stove installation manual. These guidelines are in place for a reason, and you should follow them if you want to avoid potential safety hazards.
- If your pellet stove is fitted with an anti-explosion feature, ensure you position the device correctly in its place before lighting the stove. Doing so will allow this feature to function as it should.
2. Poor Pellet Quality and Pellet Overload
Low-quality pellets ignite slowly and burn longer. Slow-burning pellets can cause an overload on the burn pot as the stove continues to feed the pellets as programmed.
A larger-than-usual pellet pile creates a “wood stove situation” where the pellets can ignite and burn in a flame, causing an explosion.
Experts recommend using high-quality pellets for your stove to facilitate a safe and comfortable heating experience. Pay attention to any guidelines from the manufacturer about the quality of pellets you should use.
Pellet quality is decided on factors such as:
- Wood type
- Moisture levels
- Dirt levels
- Pellet compactness
The Pellet Fuels Institute (PFI) proposes 3 grade standards of pellets based on bulk density and the percentage of inorganic ash and moisture:
|Fuel Property||PFI Premium||PFI Standard||PFI Utility|
|Bulk Density, cubic foot/lb||40–46||38–46||38–46|
|Moisture %||≤ 8.0||≤ 8.0||≤ 10.0|
|Inorganic Ash %||≤ 1.00||≤ 2.00||≤ 6.00|
The premium quality burns better and is less susceptible to explosions and other safety issues.
3. Lack of Pellet Stove Maintenance
The most common root cause of pellet stove explosions is the lack of a maintenance routine. Like any heating appliance, pellet stoves require regular maintenance to function properly.
If you don’t practice adequate maintenance habits, this can lead to stove malfunctions that can cause a fire to erupt inside the stove. This fire can then spread to the hopper (pellet holder), causing an explosion.
Pellet stoves require regular care by the user and seasonal professional maintenance to function correctly.
Regular pellet stove maintenance should be done by:
- Checking the burn pot regularly to preempt any ash buildup in the ash pan, as this could block the airway.
- Checking and cleaning the chimney for any fly ash or creosote buildup.
- Cleaning the air filters and ridding the hopper of pellet dust.
Professional pellet stove maintenance and cleaning should be done before lighting it at the beginning of the heating season. It entails:
- Emptying and cleaning the ash traps and chimney behind the fire chamber.
- Cleaning the motor and fan and lubricating them.
- Thoroughly cleaning the fuel feed system, the hopper, and the heat exchanger system.
- Repairing any leaks in the venting system.
- Checking and adjusting the thermostat settings if needed.
- Assessing, repairing, or replacing any worn-out electric components.
4. Blocked Pellet Stove Airway
A blocked pellet stove airway is related to the lack of maintenance. If fly ash accumulates in the ash traps and the chimney, it will block the airway. Accumulated fly ash also causes clogging of the burn pot’s air holes.
These blockages will cause the hopper and the electronic parts of the stove to heat up and cause an explosion.
The regular maintenance guidelines in the above section apply. Most importantly:
- Ensure that the ash drawer is emptied before starting a new fire and during operation if needed. How often you empty the ash drawer depends on your pellet stove model. So, check your manual.
- Check the burn pot daily and clean it regularly to leave the air holes open. The frequency of cleaning the burn pot will vary on pellet quality.
5. Low Fire Setting
A pellet stove allows you to set the fire range on the thermostat according to how much heat you require. In mild winters, homeowners will most likely set their thermostat lower to suit the lower heating requirements.
Unfortunately, this is not a wise decision!
Low fires create the conditions for low temperatures in the pellet stove chimney and creosote buildup. If you do not clean the chimney and the creosote keeps building up, a pellet stove chimney fire is looming.
Set the heating conditions so that your pellet stove burns at least 30% or more capacity to limit creosote formation.
In mild winters, you are better off burning your stove on high, then turning it off when your room is heated, rather than leaving it burning on a low setting for 24 hours.
If you choose to go for the low-burning setting, ensure you regularly clean your pellet stove chimney to eliminate any creosote. If you do the cleaning yourself, I recommend the Gardus RPS204-B Rotary Pellet Stove Cleaning System from Amazon.com. This easy-to-use kit has efficient, forward-rotating propeller brushes and adjustable rods to navigate chimney turns.
Alternatively, turn on the stove to a high setting periodically before bringing it back to the lower setting.
As a rule of thumb, set your pellet stove at ≥60°F (≥15.56°C) to reduce creosote buildup. From a different perspective, you should burn at least 40-50 lbs (18.14-22.68 kilograms) of pellets in 24 hours to reduce creosote buildup from low chimney temperatures.
A pellet stove burns a live pellet fire to heat your home. As such, it is normal for pellet stove users to wonder: “Can a pellet stove explode?”
While pellet stoves are known for being a safe heating option, inadequate installation and maintenance habits can cause explosions. Poor pellet quality and improper settings are also possible culprits.
Check your pellet stove manual for proper handling and safety guidelines to prevent any risks of pellet stove explosion.
More Pellet Stove Resources
If you have additional questions about your pellet stove, one of these articles might be able to address them: