How Does a Wood Boiler Work?
A wood boiler offers a way to warm a home using a boiler system rather than direct heat. This is a special structure with a water tank heated using wood. Once the water is heated, it moves through underground insulated pipes to reach a heat exchanger. The heat from the water is moved into a blower 1 and circulates a home through the ductwork. In many cases, the boiler needs to have its wood replenished once or twice a day. The best type of wood to use is hardwood, such as oak.
Because outdoor wood boilers can be larger, they are easier for homeowners. They can often hold large pieces of wood without splitting them. This means there is little necessary cleanup, and maintenance is simple. Also, they rarely cause a fire emergency.
Wood Boiler Cost by Type
There are two basic wood boilers: standard boilers and more efficient gasification boilers. A standard boiler tends to be a bit less expensive at $5,000 to $12,000, while gasification units run around $6,000 to $14,000. The main difference between the two is that standard boilers burn wood while gasification models also burn the gases made in the burning process.
| Type | Average Cost Range (Unit Only) |
|---|
| Standard | $5,000 - $12,000 |
| Gasification | $6,000 - $14,000 |
Standard Wood Boilers Cost
Standard boilers range from $5,000 to $12,000, depending on size. They are slightly less expensive than gasification boilers but require more wood to produce the same amount of heat. Standard boilers burn wood, heating the water used to heat your home. Like any wood-burning appliance, they generate lots of smoke-containing particulates, causing some of the heat and energy used to be lost. If you live in a neighborhood, you may have complaints from those near you about the excess smoke. This is particularly noticed in the summer, when the wood may smolder due to the lower heating needs.
Wood Gasification Boiler Prices
Depending on gas, gasification boilers cost between $6,000 and $14,000. Gasification boilers operate like standard boilers and burn the particulates in the smoke, creating less smoke and a smoky scent. The units use two stages and reach interior temperatures much hotter than standard boilers. They cost more upfront but use less wood, so they pay for themselves over time. They produce less smoke and can be installed inside and out.
To use this type of boiler, make sure your wood is well-seasoned for a minimum of two years. The dryer it is, the better it performs. Gasification models may be more expensive but lead to less smoke and smell coming from the boiler, which your neighbors will appreciate. Gasification boilers also have less soot, ash, and creosote to clean up.
Wood Boiler Price by Brand
Like any other appliance, wood boilers vary in efficiency, quality, and cost between brands. However, modern units are becoming more efficient over time due to putting better technology in place. When choosing a boiler, you can enjoy accessible heating fuel, lack of a mess inside, and other benefits. While prices can vary, most homeowners will find a version that works well for their needs. Below are some of the more popular brands for producing wood boilers and their average costs.
| Brand | Average Cost Range (Unit Only) |
|---|
| Heatmaster | $5,000 - $10,000 |
| Hawken Energy | $6,000 - $9,000 |
| Crown Royal | $7,000 - $10,000 |
| Econoburn | $7,000 - $12,000 |
| Central Boiler | $8,000 - $12,000 |
| Woodmaster | $8,000 - $14,000 |
| Heatmor | $9,000 - $14,000 |
Heatmaster
When choosing a model from Heatmaster, the outdoor wood burner cost is about $5,000 to $10,000. These are highly-efficient units that are long-lasting, easy to operate, and capable of excellent performance. They are made to meet all EPA requirements. The boilers measure exhaust and adjust the air to ensure the best heating inside your home. In addition, the boilers are made to require little maintenance and are exclusively designed for outdoor use. A full warranty is available for the first five years, and a limited warranty is provided for the life of the boiler.
Hawken Energy
Outside wood boiler prices from Hawken Energy run from $6,000 to $9,000. These are designed for use with in-floor radiant heating, hot tubs and pools, greenhouses, snow melt systems, and other buildings. These boilers are designed to meet EPA regulations. Several versions are available so homeowners can choose the level of heating right for their interior space. Each boiler is covered by a 20-year limited warranty.
Crown Royal
Outside wood burner prices from Crown Royal range from $7,000 to $10,000 and meet EPA requirements for residential use. These come in various sizes and configurations to meet the needs of all homeowners. Boilers are made to be easy to maintain and user-friendly. Each has a grate system for simple ash removal, an ash pan, and a rear access door for maintenance and installation. The systems offer a double blower system for better heat transfer. This brand provides a 20-year warranty.
Econoburn Wood Boiler Prices
Homeowners can expect to pay about $7,000 to $10,000 for wood boilers from Econoburn. These boilers are made to create max efficiency through a gasification process. They feature closed-loop, low-maintenance technology for consistent performance and excellent energy production. All units by the brand are EPA-certified for efficiency and durability and built to prevent the release of excess emissions. The boilers include a 25-year warranty on workmanship and materials.
Central Boiler
Hydronic wood boilers from Central Boiler powered by wood cost $8,000 to $12,000. These come in several types, all of which are EPA-certified for use in residential homes. All boilers are made to be easy to operate and load while offering quality, durability, and high performance. Some boilers also come with built-in wireless connectivity for easy use on the go. Using an app, you can monitor burning time, reduce smoke when reloading, and get text alerts when more fuel is needed. These units include a 25-year warranty.
Woodmaster Boiler Prices
The typical wood boiler from Woodmaster costs from $8,000 to $14,000. These boilers are high-efficiency models that meet EPA requirements. They offer clean burning heat and are simple to operate for the average homeowner. The size of the door, firebox 2, and heating area vary, so homeowners can choose the model that best meets their heating needs. A limited lifetime warranty is provided for the water jacket and fire drum, with a two-year warranty on labor and parts.
Heatmor Wood Boiler Prices
The final source of electric outdoor boilers for homes is Heatmor, which offers high-quality models for $9,000 to $14,000. Several residential models meet EPA requirements in different sizes and levels of power. These are made to have a low impact on the environment while heating spaces safely and conveniently. Choose from several chimney sizes and firebox door openings based on how much heat you need in your home. The company offers a lifetime warranty on defects in workmanship, materials, and corrosion.
What Size Wood Boiler Do I Need?
Like other boilers, wood boilers are sized depending on the heat output measured in BTUs. Unlike gas, propane 3, oil, and electric boilers, wood boilers have starting BTUs of around 95,000 to 100,000. This is more than many homes need, particularly if you live in a moderate climate.
On the other end of the spectrum, it is possible to find wood boilers that reach sizes up to 400,000 BTUs or even larger. For this reason, many people often choose a boiler that heats not only their home but also their garage, shed, barn, and other outbuildings. They may also use the boiler to heat their hot water storage tank because the system easily produces ample BTUs, so many people choose to size up.
If you live in a home under 2,000 sq.ft. in a moderate to moderate-cold climate, a 100,000 BTU boiler provides for all your needs with room to spare. If you live in a larger home, want to heat multiple buildings on your property, or live in a colder climate, determine the number of BTUs based on the total square footage and your climate.
Measure each of the areas you intend to heat in both length and width and multiply these numbers together to get the total square footage. Next, determine the zone you live in by consulting this map by the U.S. Department of Energy. If you live in zone 4 or above, a 100,000 BTU boiler will likely meet your needs unless you have a very large home. Zones 5 to 7, however, may require larger boilers. Multiply the square footage you want to heat by the number of BTUs necessary for each zone to determine the size boiler you need. If you also intend to heat your hot water, you may want to size up.
| Zone | BTUs (per Square Foot) |
|---|
| 1 & 2 | 18 - 30 |
| 3 | 25 - 35 |
| 4 | 28 - 40 |
| 5 | 40 - 50 |
| 6 & 7 | 50 - 60 |
Below are the average BTUs needed for most homes located in zone 6 based on their square footage.
| Square Footage | BTUs Needed (Zone 6) |
|---|
| 2,000 sq.ft. | 100,000 - 120,000 |
| 2,500 sq.ft. | 125,000 - 150,000 |
| 2,750 sq.ft. | 137,000 - 165,000 |
| 3,000 sq.ft. | 150,000 - 180,000 |
| 3,500 sq.ft. | 175,000 - 210,000 |
Cost to Install a Wood Boiler
Wood boiler installations are expensive, and it is a highly-skilled process that can be dangerous for the average homeowner. This is why it is recommended that you leave the installation to a professional. In addition to the boiler, you also need roughly $300 to $700 in materials and supplies to run the boiler to your home and hook it up to your heating system. Besides the boiler itself, a flue 4 or flue pipe, exhaust, drain, and a line from the outside to the interior are needed for an initial installation. This adds about 12 to 14% to the other labor costs. The boiler can directly connect to hydronic radiator systems, but most installers want to use a heat exchanger to regulate air pressure. Otherwise, they connect the boiler to an exchanger to run a forced hot air furnace. The pipes, exhaust, and connectors necessary to have the boiler heat your home vary from system to system and therefore increase your costs.
In addition, you also have boiler installation costs of around $3,000 to $6,000 for the labor since installing these systems is a time and labor-intensive job. Costs vary depending on the type of heating system you have, hydronic or forced hot air, what type of connection system you need to make, and how far away from the home you install the boiler.
Cost to Run a Wood Boiler
The cost to run this type of boiler depends on the size of the property you heat and whether you have a standard or gasification boiler. It also depends on your location and whether you have your own wood or purchase it.
If you live in an area where you gather your own wood, there are next to no running costs. You may need to purchase a permit depending on the area. There are many labor costs involved in trucking and cutting the wood, but no real monetary costs.
If you purchase the wood, you need to pay for roughly three to five cords of wood a year, depending on your needs. A cord ranges in cost depending on your location, with most people paying around $150 to $200 a cord. This means a cost of $450 to $1,000 per year for the wood to heat your home. When you break this down into an hourly cost assuming regular use, the outside boiler prices for fuel are between $0.05 and $0.11.
Wood Boiler Repair
Regular maintenance is required with a wood boiler to keep it in the best shape and avoid repairs. When repairs are needed, you may spend $150 to $1,000 or more, depending on the problem. Some of the problems that might indicate the need for repairs are a lack of heat coming from the system or less heat production than is normal. These issues can be caused by a pilot malfunction, mineral deposits, or incorrect water levels. Replacing an ignitor 5 switch may cost about $150 while replacing faulty valves or pipes could cost as much as $1,000.
If the boiler is beyond 10 years old, replacing it may be less expensive than repairing it. To get an idea of the best option, multiply the age of the boiler by the cost of the repair. If the number comes up as less than $5,000, repair it. Otherwise, a replacement is the best option. Keep in mind that a well-maintained boiler lasts from 20 to 30 years.
High-Efficiency Wood Boiler Cost
Like any boiler or furnace, wood boilers vary in efficiency depending on the type you purchase. A standard unit usually has an energy efficiency of around 75%, meaning that it converts roughly 75% of the energy used to burn the wood into heat. The other 25% is usually wasted through smoke.
Gasification boilers, which use two stages to burn the particulates in the smoke, achieve efficiency ratings of higher than 90%, so they use less wood to produce the same amount of heat. These boilers are weather-tight, self-contained, and insulated to reduce heating costs and wood consumption. High-efficiency boilers keep a precise balance of heat, oxygen, and fuel to work better than standard boilers.
Since a high-efficiency boiler is better at creating heat, they tend to be more expensive than standard boilers. High-efficiency units range from $6,000 to $14,000 for the unit and installation.
Outdoor Forced Air Wood Furnace and Boiler
You may use an outdoor wood boiler to heat your home through hydronic heat or forced hot air. Sometimes, you might hear the words outdoor forced air wood furnace, but this is still an outdoor wood boiler. The difference is that you have an indoor forced hot air furnace designed to be powered by your wood boiler.
The boiler heats water and runs it into your home via pipes. These pipes run to a heat exchanger in your ducts. Your furnace blows air through the ducts, where it warms in the heat exchanger. Your furnace needs electricity to run, so it cannot be completely off-grid without solar power or a generator. Adding a furnace increases the wood boiler cost by another $2,000 to $3,000 on top of the boiler, installation, and connection fees. This is a common choice that is often used to offer the benefits of both units.
Otherwise, use your outdoor wood boiler with a heat exchanger to power a radiator or radiant heat floor system. This is the same as an indoor boiler, but with an added heat exchanger to even out the air pressure.
Wood Boiler Pros and Cons
As with other home heating options, wood boilers have pros and cons. The first thing to be aware of is that most units are somewhat automated regarding the regulation of the combustion air. However, unlike pellet boilers or boilers that use oil and gas, they are not self-igniting. Wood needs to be fed into the unit regularly to ensure top efficiency and keep your home comfortable.
Wood can be a bulky fuel to move around, but it is also inexpensive compared to all other options. However, these boilers offer a huge advantage by being outdoors, which means they will not take up any of your living space. This is not the case with many boilers fueled by other substances.
Wood Boiler Maintenance
These units require a lot of maintenance to keep them running properly. They need to be cleaned out at least once weekly, although newer and more efficient versions have taken this process down to just a few minutes. They need to be serviced yearly, with service costs between $50 and $200 each year. During this service, the door gasket 6, pump 7, solenoid, and temperature probes should be inspected and replaced if necessary because these components are required for the boiler to run.
Wood Pellet Boiler vs Wood Boiler
Another option for outdoor boilers is a pellet boiler, which uses compressed sawdust pellets or corn. These boilers are often more efficient and use less fuel than wood. Pellet boilers are smaller, take up less space, and produce less smoke because the sawdust is drier and burns more completely.
Pellets are more expensive than wood, and you pay about ⅓ to ½ as much again for pellets than for wood. It does not burn in the hopper, so it is not possible to gather your own wood to burn in a pellet boiler.
Pellet boilers do not produce as many BTUs, so be more careful about sizing them to your home. They also have higher costs, with most boilers starting at around $14,000 to $23,500 with all installation costs.
This is more expensive than the low end of $8,000 to $20,000 with the installation of outdoor wood burner prices for wood boiler units. With a standard or gasification boiler, you can gather your own wood for a discount on your heating price. Wood boilers do not require as much maintenance and cleaning as a pellet boiler to save time. In addition, those who stock up on wood pellets might need a large space, similar to what is needed to store cords of wood.
| Type of Heating Unit | Cost (Installed) |
|---|
| Wood Boiler | $8,000 - $20,000 |
| Wood Pellet Boiler | $14,000 - $23,500 |
Indoor Wood-Burning Stove vs Outdoor Wood Boiler
If you want to heat your home with wood, you can use an indoor wood-burning stove. Indoor stoves produce heat directly, warming the room from the heat produced. If installed on a lower level, they heat the rooms above them. They work best if you install vents and fans to move the heat. Because they are indoors, they have a greater risk of fire, need to be vented for smoke, and get very hot. They are a burn or injury risk for young children. You need to install a fireproof floor below it and possibly fireproof the wall behind it.
Outdoor wood boilers heat your entire home either through forced hot water or forced hot air. Because they are outside, there is less smoke indoors and less smoke overall with gasification boilers. They are more efficient at heating and heat much larger properties than a stove. Unlike wood stoves, boilers are less likely to cause fires or injuries related to heat. They leave little to no mess inside, unlike a stove. On the other hand, stoves are less expensive, need less wood to operate, and have an aesthetic that many homeowners enjoy.
| Type of Heating Unit | Cost (Installed) |
|---|
| Wood-Burning Stove | $2,500 - $5,000 |
| Wood Boiler | $8,000 - $20,000 |
Enhancement and Improvement Costs
Solar Heat Storage
You may offset some of your wood needs by using a solar hot water storage tank. These tanks rely on the sun’s energy to heat the stored water until it is needed. They have a wide range of costs depending on the size, with most starting at $1,500 to $2,500.
Dual Fuel Systems With Gas Heat
Wood boilers need to be fed every 10 to 48 hours. If you leave your home for longer than that, you may want to have a dual fuel system. These systems monitor the burner and switch to another heat source like gas to keep the heat running. Upgrading to dual fuel increases the cost of outdoor wood boiler prices by another $800 to $1,200.
Programmable Thermostat
Like all systems, wood boilers are controlled with a thermostat. Using a programmable thermostat controls the heat in your home precisely for the times when you are not there. Expect to pay around $30 to $150 for a programmable thermostat without installation costs. It lets you turn the boiler on and off, change the temperature, and set up alerts and notifications from anywhere in the world.
Old Boiler Removal
In many cases, the person who installs your new boiler will remove the old one for no extra fee. Others may require a $50 to $200 fee in addition to the outdoor wood boiler installation cost. The fee range is based on the type of boiler, how large it is, and how old it is.
Wood Boiler Winterization
If you leave your home unattended for any length of time during the winter, winterize the boiler to prevent it from freezing. This includes making sure the fire is completely out and adding antifreeze to the tank. Antifreeze for wood boilers often comes in five-gallon buckets and costs around $15 per gallon. Some models have additional steps, so ask your HVAC technician how best to winterize.
Additional Considerations and Costs
- Firewood gathering. In some areas, you may be able to gather your own firewood. If you do so on public land, you need a permit. Contact your local government for more information, or consult the USDA if you intend to gather wood in a national forest. If you buy it, it is still less expensive than other forms of heating fuel.
- Indoor wood stoves. If you install a wood-burning stove inside, your home will smell like smoke. Outdoor boilers do not produce as strong a smell because they are outdoors.
- Neighbors. If you live near other people, keep in mind that standard boilers have a strong smoke smell, which is off-putting. You may want to invest in a higher chimney or a more efficient gasification boiler to avoid this.
- Chimneys. Look for units with internal chimneys to reduce the maintenance and avoid potential fires.
- EPA Guidelines. It is important to follow the guidelines put out by the EPA on wood-burning appliances. This includes seasoning your wood for at least two years, keeping it dry, avoiding breathing in the smoke, and paying attention to good burning practices.
- Manual J. An HVAC technician should do a Manual J calculation to decide what size of boiler is right for your space. This calculation looks at the entryways and windows in a building, how many people live there, the climate, and the home’s energy efficiency.
- EPA regulations. New regulations strengthened emissions standards for wood boilers, making some companies only offer boilers for non-residential use. One example is Nature’s Comfort. These boilers must meet standards for particulate matter and test runs to be acceptable for heating homes.
- Indoor wood boilers. Wood indoor boilers need to be installed in an enclosed space, such as a basement. They also need a wood vent to the outdoors and an air combustion system. Existing ductwork can move heat throughout the home, or a new ductwork system will need to be installed. These are most common for commercial use.
FAQs
- How do you use a wood boiler?
They are simple to use. Fill the interior with wood that heats the water. The water travels to your home via underground pipes where it is used for hydronic heat or to power a forced hot air furnace.
- How to make my outdoor wood boiler more efficient?
Choosing an outdoor wood boiler that meets the Environmental Protection Agency’s Phase II emissions standards will result in a more efficient boiler. Better quality wood will also be more efficient, so hardwood is the best option. Allowing the material to dry for a long time creates more efficient heating from an outdoor wood boiler.
- Are wood boilers worth it?
For many homeowners, they are undoubtedly worth the price. Many of these units are durable and give you energy independence since you do not need to work with an electric, oil, gas, or propane company. Gasification boilers offer fewer emissions, and outdoor boilers prevent a mess in your home. These units can save labor, money, and time.
- Can you still buy outdoor wood boilers?
Yes. Recent EPA guidelines simply require your outdoor wood boiler to be efficient and clean. Major manufacturers take care to meet all emissions guidelines to protect homeowners and the environment.
- How long do outdoor wood boilers last?
This depends largely on maintenance, but many last 20 years or more. If the boiler is corroded, warped, rusted, or experiencing frequent problems, it may be time to consider a new wood boiler.
- How far does an outdoor wood boiler need to be from the house?
This depends on the type of boiler. Gasification boilers may be located very near the home.
- Do wood boilers need electricity?
No, but if you want to use them to power a forced hot air furnace, the blower requires electricity.
- How often do you have to fill a wood boiler?
This depends on the boiler and ranges anywhere from 10 to 48 hours. It varies based on how hot the boiler is kept, the time of year, how much wind is blowing, and other factors.
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