Welcome to the Boiler Basics

Already dreading your winter heating bill?

If you’re looking to save money on heating and researching outdoor furnaces, you’ve come to the right place. This page contains everything you need to know from how outdoor furnaces work to determining your ideal size for your square footage.

Don’t spend another year paying high heating bills, see what outdoor furnaces can do for your family!

Rural Heating 101

Find your solution by comparing the cost and efficiency of the leading heating systems below.

See the differences in savings between Outdoor Wood Furnaces, Natural Gas, Propane, Heat Pumps, and many more.

Read on to see a rundown of the pros and cons of each.

Outdoor Wood Furnace

The latest outdoor wood gasification furnaces can achieve much higher efficiency numbers compared to more conventional wood furnaces, up to 90%. Because the furnace is often outside, they eliminate any issues with fire hazards and wood mess in the home. And one furnace can pump heated water to multiple buildings using a variety of applications including in-floor heat. However, wood gasification furnaces do require well-seasoned wood.


  • Efficiency

    Wood provides 30,600 megajoules per bush cord, and can provide approximately 90 percent efficiency depending on the top wood gasification furnaces.
  • Safety

    Because an outdoor wood furnace is installed outside away from other buildings, the only damage that could occur is to the furnace itself.
  • Availability

    For those who live in a forested area, wood can be abundant, free, and renewable.
  • Capital Cost

    High, outdoor furnaces can cost around $8,000 - $16,000 depending on the make and model.
  • Maintenance

    An outdoor furnace means a morning and evening trip to the woodshed to reload the firebox. Cutting and seasoning your wood is also highly recommended, which means some extra Saturdays spent working and extra tools like a wood splitter. Outdoor furnaces also require regular maintenance including cleaning out the ash and end-of-season care if you turn off the furnace in the summer.
  • Fuel Price Volatility

    If you live on a wooded property or have a neighbour who will let you clean up their deadfall, it’s free. If you have to buy wood and truck it a long way it can get expensive. Wood prices are a lot less dependent on the economy.

Who should consider Outdoor Wood Furnace

If you have wood readily available to you, wood heat can be a fantastic, economical option. However, you should be ready to put in the sweat equity and have access to the tools to cut and season your wood.

Home Heating Oil

Home heating oil furnaces can be hooked up to a forced-air duct system, or in a boiler to heat up the water in a hydronic heating system and tied into applications like in-floor radiant heat. In the winter of 2020-2021, approximately 5.3 million households in the U.S used home heating oil as their primary heat source.


  • Efficiency

    New oil furnaces can produce up to 86 percent efficiency with heating oil coming in at 38.2 megajoules per litre.
  • Safety

    Home heating oil has a high flashpoint (140 F) and at most temperatures is not flammable, making transporting & storing extremely safe.
  • Availability

    Readily available across North America, though a majority of users are in Northeastern U.S.
  • Capital Cost

    Depending on the brand and efficiency, a home heating oil furnace can cost anywhere from $2,000 – $10,000.
  • Maintenance

    Because of the high amount of sulfur in home heating oil, soot can build up and clog the spray nozzle greatly lowering your efficiency.
  • Fuel Price Volatility

    Because home heating oil depends on the cost of petroleum, global politics can heavily influence the price.

Who should consider Home Heating Oil

Anyone who is looking for a lower upfront investment and relatively little maintenance and sweat equity should consider home heating oil, just be prepared to pay more per winter as fuel costs continue to rise.

Natural Gas

With natural gas, you have the option of a gas fireplace without the fuss of preparing the wood. However, fireplaces are not as efficient as a furnace. Natural gas furnaces can be hooked up to a forced-air duct system, or in a boiler to heat up the water in a hydronic heating system and tied into in-floor radiant heat.


  • Efficiency

    Natural gas burns cleaner than fuel oil. The energy content of natural gas is 37.5 megajoules per cubic metre. Depending on the furnace, you can get up to 96 percent efficiency.
  • Safety

    While the odds are slim, there is the danger of an explosion as Natural Gas is extremely flammable. Odour is added for safety.
  • Availability

    Natural gas may not be available in all rural areas. You will have to check with your local providers.
  • Capital Cost

    A natural gas furnace will cost $2,000 - $6,000 or $5,000 - $9,000 installed. Additional costs may be incurred to connect natural gas line to your home.
  • Maintenance

    A natural gas furnace requires little day-to-day maintenance, though it’s recommended to get your furnace checked annually by a professional.
  • Fuel Price Volatility

    Extremely volatile. Unfortunately, like many fuel options, natural gas depends on the cost of petroleum and global politics can heavily influence the price and make predicting your annual heating budget more difficult.

Who should consider Natural Gas

If you have access to a natural gas line in your area, you may want to consider getting hooked up depending on the price in your province or state. Natural gas has a medium upfront investment and relatively little maintenance and sweat equity, though rising fuel costs are an important factor to consider.


Propane is often set up as natural gas, and also has the option of a gas fireplace without the fuss of preparing wood.


  • Efficiency

    Propane burns cleaner than oil. The energy content of propane comes in at 25.3 megajoules per litre. Depending on the furnace, you can get up to 96 percent efficiency. However, the fuel used to create the electricity may be inefficient: coal, natural gas, oil. Common types of electric heating include electric furnaces, radiators, and convection heaters.
  • Safety

    Propane is highly flammable and an undetected leak could result in carbon monoxide in your home.
  • Availability

    Propane can be easily delivered to rural areas
  • Capital Cost

    If you’re ok with a large tank in your yard, an above-ground 500-gallon propane tank can cost between $1,000 - $2,500, or up to $3,000 if installed below ground. Depending on the furnace size and model, you can expect to pay $1,000 - $6,000, not including installation.
  • Maintenance

    If you own your propane tank, you’ll need to schedule regular inspections and pay to fix any corroded spots that could lead to a leak. If you rent your tank, you’ll have to factor the rental fee into your budget.
  • Fuel Price Volatility

    Propane can often be the most expensive fuel in the area, and the price is known to fluctuate.

Who should consider Propane

If you’re looking for a heating solution that requires little labour and maintenance, propane is a great choice. If you rent your tank and have your inspections and deliveries scheduled in advance, you can relax and let others take care of things. However, it does mean less control over your budget.


Electricity is a common and self-explanatory heating solution. However, depending on the application, electricity can be a very expensive option, especially if you’re heating a building with less than stellar insulation


  • Efficiency

    Electricity produces 3.6 megajoules per kilowatt-hour but unlike other sources provides a full 100 percent efficiency. Common types of electric heating include electric furnaces, radiators, and convection heaters.
  • Safety

    As long as your heater is unobstructed, they remain a relatively safe and dependable heat source.
  • Availability

    Widely available
  • Capital Cost

    Electric heaters and radiators cost around $800 - $6,000 installed.
  • Maintenance

    Minimal, though if using forced air annual cleaning of ducts and heat exchangers is needed, same as gas, propane and oil.
  • Fuel Price Volatility

    Depending on the application, electric baseboard heaters can be one of the most expensive ways to heat your home, especially considering your electricity rates.

Who should consider Electricity

If you’re looking for a heating solution that requires little maintenance or upfront investment, electricity is a great option. However, just keep an eye on electricity rates and be prepared for higher electricity bills during the coldest winter months.

Indoor Wood Stove

Like a fireplace, an indoor wood stove can create a very inviting atmosphere. Though they do create a fire hazard concern, and the regular ash and wood mess inside the house.


  • Efficiency

    Wood provides 30,600 megajoules per bush cord, though an indoor stove can’t match the efficiency of other heating solutions, which means more energy goes to waste.
  • Safety

    An indoor wood stove does carry the risk of a fire and smoke inhalation.
  • Availability

    For those who live in a forested area, wood can be abundant, free, and renewable.
  • Capital Cost

    An indoor wood stove can cost anywhere from $800 - $4,000 plus installation.
  • Maintenance

    An indoor wood furnace means regular trips to the woodshed to reload the firebox. And you’ll want to clean out the ash and wood mess regularly, including chimney cleaning.
  • Fuel Price Volatility

    If you live on a wooded property or have a neighbour who will let you clean up their deadfall, it’s free. If you have to buy wood and truck it a long way it can get expensive.

Who should consider Indoor Wood Stove

If you have wood readily available to you, an indoor stove can be a fantastic, economical option. However, you should be prepared for ash and wood mess in your home and the smell of smoke. But for those who want control over their heating bill and appreciate the cozy feeling of warming up by the fire.

Heat Pump

Heat pumps are a newer trend in heating. Interestingly, they don’t actually create heat but extract the existing heat outside and pump it into your home or building to raise the indoor temperature.


  • Efficiency

    While heat pumps can be very efficient in most temperatures, during colder months they can struggle to generate much heat, making them less practical in colder climates.
  • Safety

    Heat pumps are incredibly safe as they don’t require any fuel or produce noxious gases. They don’t have super heated components so there’s no danger of burning or scalding either.
  • Availability

    Widely available and doesn’t require any fuel.
  • Capital Cost

    High. Heat pumps can cost anywhere from $5000 - $9,000 not including installation.
  • Maintenance

    While heat pumps don’t require much maintenance or cleaning, because of their complex nature technical support might not always be readily available in rural areas
  • Fuel Price Volatility


Who should consider Heat Pump

If you live in a milder climate and can stomach the higher upfront cost, a heat pump can be an excellent heating solution. Though if your winters get frigid where you live, you might want to consider a heat pump as a spring and summer appliance.


Geothermal moves heat from one place (the ground) to another (your home). A loop of pipes essentially takes the heat from underground where it stays constant at around 50F year-round and pipes it into your home with a compressor. However, like a heat pump, you may still need a secondary heating system in colder climates.


  • Efficiency

    Extremely efficient. For every unit of electricity required to run the system, geothermal can provide 3 units of heating energy.
  • Safety

    With no combustion or fuel required, a geothermal system is very stable and safe.
  • Availability

    Unfortunately, geothermal contractors are not available everywhere, and you’ll have to check your local market.
  • Capital Cost

    Quite high, upwards of $30,000. The cost of excavation and the network of pipes is a large investment, plus the cost of landscaping. You’ll also want to factor in the electricity costs to run the compressor. However, if installed poorly, the system will never reach its potential. If designed and installed well it can pay itself back in less than ten years.
  • Maintenance

    There is minimal ongoing maintenance to the installed lines themselves, but you’ll need to take good care of the equipment pumping water and antifreeze through the system as it transfers heat.
  • Fuel Price Volatility

    Never pay a heating bill again, but expect a larger electricity bill to run the compressor. Unfortunately, you’ll still likely require a backup heating system to ensure your indoor temperatures remain consistent.

Who should consider Geothermal

If you live in a warmer climate, geothermal systems can be an optimal solution. Like heat pumps, however, they still make great supplemental heating options if you can stomach the upfront costs. Then you can watch your heating bill drop dramatically as the system pays for itself over the course of multiple winters.


It’s easy to see that where you live can become the biggest factor in which heating solution is available to you and which one is the most cost-effective.

Your preference for a hands-off solution vs. one that requires a bit of elbow grease can determine your ongoing costs both to your wallet and your personal time, and how dependent you want to be on fuel companies. In the end, you have to find the heating solution that best meets your needs.

Frequently Asked Questions

Why are people upgrading to outdoor boilers?

We asked customers why they were switching and here’s what they said:

  • “Looking for a cheaper heating system in the long run. Propane is too expensive.”
  • “Received my hydro bill… yikes. Always liked the idea of having more control over my heating.”
  • “Gonna take our wood stove out and I want an outdoor boiler to cut down on dirt, smoke etc. in the house. Also gonna build a garage and heat it too.”
  • “We are currently building a house and planning the heat source.”

Is a boiler right for me?

An Outdoor Wood Furnace could be your heating solution if…

  • You live out in the country
  • You have access to wood
  • You have the tools to split your wood
  • You have the patience to season your wood

What is the big deal about wood boilers?

If you source your wood locally, you have cost-effective heating fuel. The best part is you maintain your independence from fuel companies and fluctuating prices.

Not to mention a warm home, shop, and garage, as well as unlimited hot showers.

How much money will I save?

Every building and region is different, but on average, it’s estimated a home in the Northern U.S and Canada needs 100 million BTUs each winter.

So if you’re paying $2.50/gallon for propane, you can expect a total heating bill of $2,881 each winter.

If you have the time and expertise to collect and season your own wood to feed your outdoor furnace, it’s easy to see how those costs could become annual savings.

How does an outdoor boiler connect to my home?

A boiler can connect to almost any existing home heating system, or power an overhead forced air heating unit or an in-floor heating system. Read more here or watch the animation below to see how a boiler connects to a home’s forced air heating system.

Learn More About How an Outdoor Furnace Heats Your Home

Watch Video

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An Outdoor Furnace Provides Heat For A Wide Range Of Applications

Tying into a home’s existing forced air system is one of the most common outdoor furnace applications. Water from the outdoor furnace heats the copper coils in the heat exchanger while and the fan pulls the air over the coils before circulating it through your home’s ductwork. You save money with low-cost wood heat, while your existing electric furnace provides peace of mind as a backup heat source.

Radiant in-floor heat is one of the most comfortable and luxurious methods to heat a home. Hot water is simply pumped from an outdoor boiler through tubing installed in the floor. Hydronic radiant heating systems are popular because they evenly distribute heat to homes, garages, barns, and more. They also last longer than electric systems. When used with an outdoor furnace like the HeatMasterss G series, a hydronic radiant floor system can also be an extremely cost-effective way to heat your home.

Tying an outdoor furnace into a home’s domestic water means the added luxury of unlimited hot water all year round. Just another benefit your family is sure to love… you’ll start to wonder how you ever lived without the unlimited hot showers.

Radiant hydronic baseboards are an excellent way to heat your home with an outdoor furnace. The baseboard heaters keep rooms warmer longer because the fluid retains the heat and evenly distributes the it throughout the space. Radiant hydronic baseboard heaters feature low operating costs, don’t require ductwork, are extremely quiet, and don’t create drafts or breezes.

Heating large buildings like shops or barns can get expensive using electricity or propane. And options like heat lamps can pose a fire danger because of the exposed heat source. However, an outdoor furnace is a safe and efficient way to keep animals comfortable during the winter months. Applications include using a water-to-air heat exchanger, in-floor radiant heat, or hydronic baseboard and wall panel heaters. Because radiant heating warms objects directly rather than the air, it’s a great option for buildings with doors that often stay open.

Using the hot water from an outdoor furnace is a great option to heat your pool. A water-to-water heat exchanger will transfer the heat from your furnace lines to your pool water without mixing the two liquids. A common method is the tube and shell heat exchanger. Inside, hot water runs through tubes in one direction, while cool water runs in separate tubes in the opposite direction. The hot fluid indirectly warms up the cool fluid, keeping your pool at the ideal temp.

Which Furnace is Right For Me?
Gasification vs Conventional

What’s the big deal about “gasification”? The process of gasification supercharges your efficiency by using extreme heat to unlock and burn the gases inside wood. While gasification is often the best choice, it does require properly seasoned wood. Check out this animation on the left for a closer look at the science of wood gasification furnaces.

While not as efficient, a conventional outdoor wood furnace is more forgiving when it comes to fuel quality. However, improperly seasoned wood still means more heat wasted boiling off moisture in your fuel.

Watch Video

For a deep dive into gasification, we sat down with our head engineers. Check out our 4 Levels of Gasification series on YouTube

Sizing Your Furnace

To choose the perfect size of furnace, you’ll need to know how many BTUs your buildings require.

Your local HeatMasterss dealer can provide an in-depth heat-loss calculation, but for a helpful ballpark number use the calculator below:

For a helpful ballpark calculation, first, think about your insulation level

Now, multiply your insulation level by the total sq. ft. you are heating (house, garage, barn, etc.). Remember, for a basement, divide the sq ft. by half and add it to your total. So a 1,200 sq. ft. basement would actually only add 600 sq. ft. to your total.

This is only an estimate. Contact your local dealer for a full heat-loss inspection.

Interested in a full heat-loss calculation by
a certified dealer? Connect with a pro today!

Find a Dealer

Installing a HeatMasterss Boiler

  • Outdoor Installation

    Location: Boilers are very safe, but for the highest level of fire safety, it’s a good idea to place your boiler between 30 to 100 feet away from your house. Remember, this distance might differ depending on your location. Make sure to check your local building codes to get specific guidelines for your area.

    Concrete pad or foundation: A concrete pad can help to keep your boiler level and make it easier to clean around the boiler. This is not a required step, but it can make maintenance easier and help to extend the life of your boiler.

    If you choose not to pour a concrete pad for your boiler avoid soft and uneven ground. Over time, soft ground can cause the boiler to sink or sit uneven which can impact the performance of your boiler.

    Connecting the Boiler to Your Home: To connect the boiler to your home heating system, lines will have to be run underground from the boiler to your home. The piping will be distributing hot water up to 204 degrees Fahrenheit. The heat is transferred, and the water is then returned to the outdoor furnace to be heated again.

  • Indoor Installation

    One big advantage our G Series has over other boilers is that they can be installed indoors. Most do this in a garage or wood shed. Refuel your boiler in the dead of winter, sheltered from the elements.

    If you’re planning to install indoors, it’s a good idea to let your dealer know so they can help you plan accordingly.

    Watch for combustible materials: Prioritize safety by keeping the unit away from any combustible materials.

    Clearance: A minimum clearance of 6 inches around all sides of the boiler should be maintained to eliminate any risk of fire hazards.

    Make sure to leave a comfortable 24 inches of space from the front door to nearby objects. This way, you’ll have enough room to move around and access the boiler easily whenever necessary.

  • Installing Rhinoflex piping in the ground

    Rhinoflex piping is installed in the ground distributing hot water up to 204 degrees Fahrenheit from your boiler to your home heating system. The heat is transferred, and the water is then returned to the outdoor furnace to be heated again.

    The kind of pipe you use can make a big difference on how efficiently your boiler heats your home. The less insulated your piping is, the more your heat will leak into the ground before it reaches your home heating system, making your system less efficient. Although you can use what ever kind of piping you want, we recommend using Rhinoflex because of it’s quality material and insulation level.

  • What to Consider:

    Apart from the pipe (which is sold separately), the rest of the components here are included with your boiler for installation.

  • Pump and circulation equipment

    The G series boiler comes with a handy recirculation pump already installed. It helps distribute the heat evenly throughout the water in the boiler. You know how sometimes the hot and cold water can separate and cause uneven temperatures? Well, this pump prevents that from happening, so the water temperature stays the same from the top to the bottom of the boiler. When you’re setting up the boiler, you’ll just need to add an additional pump to circulate the water to your heating applications or heat exchangers. That way, everything works smoothly and efficiently.

  • Fittings

    When it comes to hydronic systems, there are several common fittings you’ll come across. You’ve got ball valves, PEX fittings, and different types of control valves. Then there are tempering valves, mixing valves, bypass valves, isolation flanges, crimp rings and air bleed offs! Those help get rid of any air that might be trapped in the system.

    These fittings play a crucial role in keeping everything running smoothly and making sure your hydraulic system works like a charm. It is best to review your system with your dealer, a qualified plumber or HVAC contractor.

  • Chimney components

    HeatMasterss boilers come with a convenient double wall insulated chimney already installed. It’s great because if you ever need to extend the chimney past a roof or a roof line, it’s a breeze! The double-wall insulation helps prevent condensation and creosote buildup. So, no worries about complicated chimney modifications when you’re setting up your HeatMasterss boiler.

  • Seasoning wood

    Means allowing the wood to dry properly before using it. Freshly cut or green wood contains a high moisture content, which can cause a range of issues if not addressed. When you burn wet or unseasoned wood, it can produce a lot of smoke, is less efficient (releases less heat), and can cause creosote to buildup in your chimney and the firebox, which can be a fire hazard. By properly seasoning wood, you allow the moisture content to decrease over time, making the wood more efficient for burning. It typically takes a year or more to season, depending on the type of wood, climate, and drying conditions.

  • Storing wood

    During the seasoning process, the wood should be stored in a well-ventilated area, protected from rain and moisture, and stacked in a way that allows air circulation around the pieces. This helps the moisture to evaporate more quickly and ensures the wood becomes dry and ready for use.

  • Water samples

    Properly treated water is critical to prevent corrosion and get the longest possible life from your furnace. You need to submit a water sample to HeatMasterss each year for testing and follow the treatment recommendations to extend the lifespan and maintain the warranty.

  • Maintenance

    Refer to your owner’s manual for specific maintenance requirements for keeping your furnace operating at peak efficiency for years to come.

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