How It Works!!
There are many reasons why someone would decide to purchase a wood pellet burning appliance. It may be cost of operation, efficiency, environmental concerns, safety or beauty. But, by far, the most common reasons for buying a pellet stove are cleanliness and convenience. Here are some hints and information that will help you to understand your pellet stove and keep it operating cleanly and efficiently. As always, remember to follow the safety guidelines outlined in your owners manual.

About Your Stove
The fuel is stored in a bin at the rear of the pellet stove and is usually referred to as the "hopper". At the bottom of this bin is an opening that allows the fuel to enter into the fuel feed system.

The fuel feed system moves the pellets from the storage hopper to the combustion chamber. The most common style of fuel feed is a screw auger driven by a slow moving high torque motor. Although these feed systems are extremely reliable, an occasional jam is possible. If you should experience a jam please refer to your owners manual or contact your dealer for instructions. Shorter pellets allow for more fuel to fit into the auger opening offering a consistent feed which is very desirable for operation on low burns as well as reducing stress and wear on the fuel feed components. If you use a pellet which is shorter than what was previously used, an increase in the air rate may be required to compensate for the additional fuel that will be dispensed by the auger. Very long pellets have a tendency to bind together to form a log jam or bridge over the feed opening interrupting the fuel feed. It is very important to keep the fuel feed opening free of fines as they can obstruct movement of the fuel into the feed system. It is recommended that you vacuum or allow the hopper to run completely empty once every ton or fuel.

The fuel has now successfully been transported from the hopper to the combustion chamber. This area is sometimes referred to as the "firebox" where the burning of the fuel actually takes place. Contained in the combustion chamber is the burnpot and the heat exchanger.

The Burn Pot
The burnpot accepts delivery of the incoming fuel and mixes it with forced air to produce a hot, clean burning fire. There are obviously several different styles of burnpots and different ways of adding air to the burnpot for proper operation of your stove. This area must be kept clean for the best mix of air and fuel.

Air To Fuel Ratio
The burnpot acts as the carburetor for the stove, mixing the air and the fuel. Just like a car, the adjustment of the air and fuel rates on a pellet stove is crucial to optimum performance. Under normal operation the flame in your stove should appear to be bright yellow or white. You may experience a white or gray build up of ash on the glass on high burn and a darker fluffy ash on low burn. If you notice a lazy orange sooty flame or build up of a brown sticky caramel like substance, these are signs of an improper inefficient burn. Some stoves are equipped with air dampers or adjustable feed openings that you may personally be able to adjust. Other stoves will require adjustment to the control board which may require a qualified technician.

Clinkers
You may also experience in the firebox what is referred to as "clinkers". A clinker is a hard ash formation that is occasionally created when the ash that is present in the burnpot actually begins to melt. Many of today's highly efficient pellet stoves operate near the combustion temperatures that are required to melt ash. Once the ash begins to melt it may obstruct the air holes of the incoming air and affect the proper mix of air and fuel. Incorrect adjustment of the air to fuel ratio can greatly increase the likelyhood of clinker formation. This is due to the stoves inability to adequately burn the excess fuel and remove the excess ash that is building up in the burnpot. Clinkers are very easily removed by use of the ash tool or rake that is supplied with your pellet stove. This can quite often be performed while the stove is in operation. Care must be taken not to remove all of the hot coals or the stove will go out and, as always, you should be careful of the hot surfaces of the stove.

The Heat Exchanger
Also located in the combustion chamber is the heat exchanger which is designed to transfer the heat being produced by the burning fuel in the burnpot into clean hot air for distribution into the home. This is usually done by a chamber or a series of tubes located in the firebox that the hot air and gases pass over, heating the outside of the chamber before exiting the stove. Fresh air is passed through the inside of the chamber drawing the heat out of the stove and into the room. For maximum efficiency the surface of the heat exchanger should be cleaned regularly. The frequency of these cleanings will depend on your stove design and may range from daily to monthly. Please refer to your owner's manual for cleaning instructions.

Exhaust Venting
At this point your pellet burning appliance has performed the function that it was designed for and all that is left are the by-products of combustion, which are exhaust gases and ash. The two main styles of exhaust venting are natural draft and power. Both remove the harmful gases from inside your stove to safely outside the home. Natural draft venting uses the hot air and gases inside the stove to naturally rise and exit out through the vent pipe in much the same manner as a traditional woodstove. Power venting uses a mechanical fan to either push or pull the gases out of your stove. This style of venting is very similar in operation to the venting used on a clothes dryer. Always be sure to strictly adhere to the manufacturer's exhaust installation guidelines. Incorrect installation of the exhaust system will result in operational and performance problems.

Vent Maintenance
Also carried out through the vent pipe are small amounts of very fine ash. This ash can eventually build up and block the vent if not properly cared for. Many stoves have ash bins or traps to capture the ash in the firebox or vent outlet prior to reaching the vent that require occasional cleaning. In the event that your vent pipe should become blocked a small amount of smoke may leak into your home. Most pellet burning appliances are equipped with a safety switch that will interrupt its operation and minimize any possible exposure. A regular inspection and cleaning schedule should be maintained to ensure proper operation. While inspecting the vent system, particular attention should be paid to the assembly joints for possible leaks. Leaky joints may cause poor performance as well as result in exhaust gases and ash leaking into the home. Many stove manufacturers recommend the use of high temperature silicon sealant on the exhaust vent joints to prevent leaks.

Additionally, it is suggested that you only use a vacuum that is specifically designed for cleaning wood and pellet stoves. A standard household vacuum cleaner does not have the proper filter that is needed to trap the very fine ash produced by a pellet stove and will force that fine ash into your home creating a thin film of dust on your furniture. It is always recommended that a non-combustible pail with lid be used to remove ashes from your home and that ashes always be disposed of safely.

Solutions To Common Problems
If you should experience a dirty or sooty burn in the combustion chamber some possible corrective measures are:

• Review proper adjustment of any air dampers if your stove is so equipped.
• Remove any excess ash, carbon or clinkers from the burnpot.
• Clean any air filters or air inlets to the appliance.
• Remove (if possible) the burnpot and clean the air openings in the burngrate.
• Inspect the burnpot and burngrate for proper fit and possible air leaks. Note: Many stoves are equipped with gaskets in this area that should also be inspected.
• Inspect door and window seals for leaks.
• Clean firebox and vent ash traps.
• If possible, re-adjust your air and fuel feed rates for a leaner burn. This is an adjustment that may need to be performed by an authorized stove technician.

The first thing you should do when you encounter a problem with your pellet burning appliance is to review the instructional video and/or manuals supplied with your stove. If you can not resolve the problem, then contact your retailer for additional instructions.

Maintenance Checklist
To ensure optimum performance from your pellet stove perform the following maintenance procedures regularly. (Your stove may or may not be equipped with the items listed below.)

• Adhere to the cleaning and maintenance schedule as outlined in your owner's manual.
• Store your fuel in a clean dry place.
• Occasionally clean your hopper of pellets and fines.
• Regularly clean and inspect your vent system.
• Clean and lubricate fans as suggested.
• Never use your household vacuum to clean the firebox of your stove.
• Inspect and clean the firebox and vent system ash traps as suggested.
• Keep air filters clean.
• Clean your heat exchanger as recommended.
• Inspect and clean the burnpot if necessary.
• Inspect and adjust door seals.

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     As you can see the operation of your pellet burning appliance may not be as complicated as you may have thought. There are many things that you, as a consumer, can personally do to ensure its proper operation. You may wish to review your owners manual or video at this time to acquaint yourself with the appropriate operation, cleaning and maintenance schedule for your particular stove.

 

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Look at a picture describing the process.