How Does a Propane Boiler Work?
Boilers consist of a closed tank where water is placed under pressure and heated. A propane 1 unit is fueled using propane to ensure the home is kept at a comfortable temperature. A valve controls the movement of propane, which is burned by a burner. It controls how much air is mixed with gas to ensure top efficiency. Next, the gases from the burning of fuel move to the heat exchanger, which takes heat from the gases and moves it to the water. It remains as hot water or turns into steam before being vented into the home. It is taken to cold areas, and then the process begins again.
Hot Water vs Steam Propane Boilers
Propane boilers heat your home in one of two ways: through heating water and circulating it to radiators or hydronic radiant heat systems before it comes back to the boiler or producing steam that moves to upright radiators before condensing and moving back to the boiler. While both types of boilers do the same thing by heating the home, they do it differently. In addition, prices can vary between the two types based on their quality and the amount of work they can handle.
| Type | Cost (Unit Only) |
|---|
| Hot Water | $1,200 - $5,500 |
| Steam | $2,500 - $8,000 |
Hot Water Propane Boiler Prices
This unit costs from $1,200 to $5,500. One of the perks of this system is that it can be used in several zones to control heat across a larger space. In addition, these tend to be quiet and nearly undetectable other than providing warm air in a space. However, hot water propane boilers are not as efficient as steam boilers and may not last as long.
Propane Steam Boiler Cost
Steam boilers are more expensive than hot water units at $2,500 to $8,000. This is the most efficient method of heating the home. It also has the benefit of being a technology that creates long-lasting boilers. However, steam boilers have single-zone technology, so that you may need more than one for different areas. If radiators are used with the boiler, they can be louder than when using hot water as a heat source. Because of their size and heating method, steam boilers have higher starting costs than water boilers despite their lower efficiency.
Condensing vs Non-Condensing Propane Boilers
Propane boilers come in two different types, known as standard and condensing. Both are capable of offering heat and hot water in a residential home. Choosing between the two requires comparing several factors and deciding which is right for your needs. It can be a balancing act between power, efficiency, cost, and required maintenance. Each unit type works through a burner and propane that create heat to ensure your home is comfortable.
| Type | Average Cost (Unit Only) |
|---|
| Non-Condensing/Standard | $1,200 - $4,000 |
| Condensing | $3,000 - $8,000 |
Standard Propane Boiler
Standard boilers that heat water and vent exhaust directly through a cast iron pipe are priced between $1,200 and $4,000. Some of the energy used to heat the water and your home is lost through the exhaust. A standard unit achieves anywhere from 80% to 94% efficiency, depending on the type of heat exchanger. This unit will have a single combustion chamber, heat exchanger, and a higher carbon footprint.
Condensing Propane Boiler
Condensing boilers are more expensive than standard boilers and range from $3,000 to $8,000. A condensing unit takes the exhaust and condenses it to retrieve heat and energy before venting the remainder. By doing so, this boiler reaches efficiencies of 98%. However, this requires a stainless steel heat exchanger and a drain for the condensate, which is highly acidic. Condensing boilers save money on your energy bills each month but are more expensive overall and do not last as long.
Sealed vs Non-Sealed Combustion Propane Boilers
Boilers also come in both sealed and non-sealed combustion forms. In a non-sealed combustion unit, the unit needs to take inside air to aid combustion, meaning it is taking the heated air from your home and lowering the efficiency of the heater. It also means that dangerous gasses from the boiler may escape into your home.
Sealed combustion boilers take air from the outside, making them more efficient than non-sealed combustion boilers. They are also safer, as there is no chance for the gasses to escape into your home. Non-sealed combustion boilers cost between $1,200 and $4,000, while sealed combustion ranges from $1,200 to $8,000 in costs.
| Type | Average Cost (Unit Only) |
|---|
| Non-Sealed Combustion | $1,200 - $4,000 |
| Sealed Combustion | $1,200 - $8,000 |
Propane Boiler Costs by Material
Choosing the right material for the heat exchanger is crucial. The heat exchanger inside the boiler is made of one of three different materials, cast iron, aluminum, and stainless steel. Each has different attributes that make it a better fit for one situation and different costs and life expectancies. Below are the average prices for boilers based on the heat exchanger material. These calculations are based on a 70,000-BTU unit for a 2,000 sq.ft. home.
| Material | Average Cost (Unit Only) |
|---|
| Cast Iron | $1,200 - $3,000 |
| Aluminum | $2,500 - $3,500 |
| Stainless Steel | $3,000 - $8,000 |
Cast Iron
Cast iron boilers cost between $1,200 and $3,000. Most older boilers and some new standard boilers use a cast-iron heat exchanger. Cast iron is heavy, long lasting, and the least expensive material. It is not uncommon for a cast iron unit to last 25 to 30 years or more. However, it is not as efficient at transferring heat as the other materials. It may not be used in high-efficiency condensing boilers.
Aluminum
Aluminum boilers cost between $2,500 and $3,500. Aluminum is lighter than cast iron, allowing for wall-hung boilers. It also does a better job of transferring heat, so it has a higher energy efficiency rating at 94% on average. It is not usable in high-efficiency condensing boilers. It does not last as long as cast iron because moisture causes oxidation on the material, and oxygen can create a hard surface skin. The moisture in the boiling process is not as damaging to stainless steel. Most aluminum units last about 10 to 15 years.
Stainless Steel
Stainless steel boilers typically cost between $3,000 and $8,000. Stainless steel is a lightweight material that is excellent at transferring heat. It is used in high-efficiency condensing heat exchangers because it resists the corrosion resulting from the high acidity in the condensed water better than cast iron or aluminum. This is the most expensive material, and while a stainless steel unit lasts up to 15 years, the warranty is only good for 7 years in most cases due to the eventual corrosion.
Propane Boiler Costs by Brand
Propane boilers are very common and created by several popular brands in the heating and cooling world. The cost of a hydronic propane boiler varies a great deal based on its size, extra functions, and technology. Prices also vary based on whether a standard or high-efficiency model is chosen. Below you will find propane gas boiler prices from various brands for homes large and small.
| Brand | Average Cost (Unit Only) |
|---|
| Slant/Fin | $1,200 - $8,600 |
| Rinnai | $1,500 - $4,000 |
| LAARS | $1,500 - $6,500 |
| Weil McLain | $1,500 - $7,500 |
| Navien | $1,700 - $3,000 |
| Lennox | $1,700 - $4,200 |
| Utica | $1,700 - $5,000 |
| Peerless | $2,000 - $8,000 |
| Buderus | $2,000 - $8,000 |
| Carrier | $2,200 - $6,000 |
| Bosch | $3,000 - $7,000 |
| Lochinvar | $3,000 - $8,000 |
Slant/Fin
When choosing Slant/Fin, a propane unit price ranges from $1,200 to $8,600. This company offers a wide variety of boilers that are highly-rated. Both steam and hot water models are available. This is a family-owned business that offers high-efficiency and standard propane boilers. The energy efficiency is average, and the costs are low for the simplest models. Most boilers from Slant/Fin have a lifetime limited warranty, but some have a 10-year warranty.
Rinnai
Propane boiler furnace costs from Rinnai range from $1,500 to $4,000. These are condensing boilers made to be dependable and user-friendly for residential homes. Both heat-only and combination boilers are available and support propane. Steam and hot water versions are available. The boilers include an onboard display to view information about the unit easily. There is also a reset sensor that adjusts to changes in the temperature. The boilers have a limited warranty of 1 year on labor, 2 years on parts, and 12 years on the heat exchanger.
LAARS
Choosing a unit from LAARS costs from $1,500 to $6,500. This brand makes fewer boilers but has an excellent reputation for quality. Many of the boilers include stainless steel sleeves with aluminum cores. Some also have modulating burners to provide the right amount of hot water to keep a home comfortable and warm. Both steam and hot water versions exist. The warranty for LAARS propane boilers is limited and lasts up to 10 years for the storage tank and up to 20 years for the primary heat exchanger.
Weil McLain
Expect to pay about $1,500 to $7,500 for a propane unit for baseboard heat and other purposes from Weil McLain. This popular brand manufactures all boilers in the United States. The boilers are available in several materials and styles to meet the needs of diverse individuals. Many boilers include elastomeric seals and a stainless steel fire tube heat exchanger for quality. They come in both hot water and steam varieties. The parts warranty lasts 2 years, while the heat exchanger is guaranteed for 20 years from the date of purchase.
Navien
A unit from Navian is priced between $1,700 and $3,000 for a budget-friendly option. The boilers are available in a tankless style between two different series, some of which are combi boilers. All heat exchangers are stainless steel for strength and durability, and the boilers meet Energy Star standards. The boilers have exceptional technology and can heat up to three zones at once. Both steam and hot water versions can be purchased. The warrant varies based on the product but averages one year for labor and five years for parts.
Lennox
Homeowners can choose a propane unit for in-floor heat and pay about $1,700 to $4,200. Both high-efficiency and standard models are available in steam and hot water versions. This provides a wide variety of options for homeowners looking to heat a space with a propane unit. The high-efficiency models are Energy Star certified and help you save money on your utility bills. The general warranty lasts from two to five years, but a 20-year warranty is provided on the heat exchanger.
Utica
Utica unit ranges from $1,700 to $5,000. This American company has been in business since the 1920s. They offer a selection of boilers to produce hot water and hydronic heat. Steam-only and hot-water only versions are available to increase the number of options. Many of the units can be wall-hung to take up very little space in the home. There is a five-year warranty on defects in materials and workmanship and a ten-year warranty on the heat exchanger.
Peerless
Peerless has a wide variety of units, from $2,000 to $8,000. The boilers come with heat exchangers in cast iron and stainless steel to provide options to homeowners. Many of the boilers are Energy Star certified, and others are combi boilers that provide heating and hot water at the same time. This brand has one of the largest selections of boilers on the market, including both steam-only and hot water units. A one-year warranty is provided for defects, but the heat exchanger warranty is often over a lifetime.
Buderus
The selection of units from Buderus costs from $2,000 to $8,000, depending on size and design. Both conventional and gas condensing models are available from the brand. Some boilers from the brand have a patented aluminum silicate heat exchanger to ensure the best efficiency during condensing mode. Others are made specifically for use in high elevation locations. Homeowners can choose from hot water or steam boilers. After registering the unit, a five-year limited warranty is available on parts. The heat exchanger is guaranteed for up to 20 years.
Carrier
Whether you need a propane boiler for radiant heat or other purposes, the models from Carrier cost $2,200 to $6,000. This brand focuses on putting out quality boilers instead of having a huge line-up of unique products. Many of the boilers are made to meet Energy Star criteria. What makes Carrier products unique is that you cannot buy a boiler on its own. Instead, a local dealer provides the boiler and installation together. Steam and hot water boilers are available. The parts warranty lasts 10 years, while the heat exchanger warranty ranges from 12 to 20 years, depending on the chosen model.
Bosch
When purchasing a Bosch unit for hydronic heating, expect to pay $3,000 to $7,000. These boilers are made to offer reliable hot water and heating with low operating costs and high efficiency. Both condensing and non-condensing models are available to offer options to homeowners. Many of these are combi boilers with up to 95% efficiency. Some models come in various sizes, so you can choose the right one for your home. You can also choose between hot water and steam models. The length of the warranty varies based on the unit but can last up to five years originally with a 15-year warranty on the heat exchanger.
Lochinvar
Lochinvar also makes propane boilers that cost between $3,000 and $8,000. The brand provides nearly a dozen models. Traditional and combi boilers are available in a space-saving size that avoids cluttering up a home. These boilers are available with various BTU options and have up to 95% efficiency. Some also include a Smart System for easier operating control. Choose between steam-only or hot water versions based on your needs. The unit has a 10-year warranty on the heat exchanger, 5 years on the burner, and 18 months for all other parts.
What Size Propane Boiler Do I Need?
Like other HVAC equipment, it is important to make sure you get the correct size boiler for your property. A unit that is too small struggles to heat your home, and a unit that is too large wears out quickly and costs more in fuel.
To determine the best size boiler for your home, you need to know your climate zone and the number of square feet you heat. Find your climate zone by visiting the U.S. Department of Energy’s climate zone map. To get your square footage, multiply the length and width of each room in your home that you heat. Add up the results to get the total square footage of your home.
Propane boilers are sized by BTUs or British Thermal Units. Each climate zone has a recommended number of BTUs per square foot to heat a home comfortably. Locate your area on the map to discover your zone. Below find the number of BTUs per square foot for each area.
| Climate Zone | BTUs per Square Foot |
|---|
| 1 & 2 | 18 - 30 |
| 3 | 25 - 35 |
| 4 | 28 - 40 |
| 5 | 40 - 50 |
| 6 & 7 | 50 - 60 |
Multiply your square feet by the number of BTUs per square foot recommended for your area to get the general size of unit you need. Keep in mind to stay within 10% to 20% of this range. If you go any larger than this, the boiler will be too large for your home. Below is the number of BTUs needed for several home sizes located in zone 4.
| Square Footage | BTUs Needed |
|---|
| 800 sq.ft. | 22,400 - 32,000 |
| 1,000 sq.ft. | 28,000 - 40,000 |
| 1,200 sq.ft. | 33,600 - 48,000 |
| 1,500 sq.ft. | 42,000 - 60,000 |
| 1,750 sq.ft. | 49,000 - 70,000 |
| 2,000 sq.ft. | 56,000 - 80,000 |
| 2,500 sq.ft. | 70,000 - 100,000 |
Propane Boiler Installation Cost
The cost to install a propane boiler varies depending on several items, including the size and location of the boiler, whether it is sealed or unsealed, standard or condensing, and whether you have the drains, exhaust, and fuel lines in place or not. It costs between $2,600 and $4,000 in labor fees to install a propane boiler. If you need a new exhaust vent, drain, propane fuel line hookup, or other work, the price increases with additional costs from $500 to as high as $5,000.
Installing this type of boiler can be a lengthy and challenging process for an individual, which is why a professional installation is the best solution. HVAC professionals commonly handle these tasks. Every installation is unique based on the fuel type, location, and whether the boiler is high-efficiency. If the residence does not already have a drain for high-efficiency models, a flue pipe or flue and an exhaust are needed for proper installation. This process can take two to six hours, depending on complexity. A professional will do things quickly and correctly while having the right tools and parts to handle the process in one appointment.
Propane Boiler Replacement Cost
Many unit installations are replacements, meaning you already had a propane boiler and are replacing it with a newer model rather than installing a unit for the first time. In most cases, the boiler you are installing for the replacement is newer, more energy-efficient, and requires things in its setup that older boilers did not, such as exhaust vents, drains, and new fuel lines. For this reason, the average cost to replace a propane boiler is about the same as it is to install a new one, $7,500 for a boiler designed for hydronic heating. Sometimes, HVAC companies dispose of the old boiler for no charge. However, some may charge between $50 and $200 for removal and disposal, depending on its age and location.
Cost to Run a Propane Boiler
Propane is more expensive than natural gas but is usually less expensive than either oil or electricity. Several factors determine running costs for your propane boiler, including the cost of propane in your area, the size of the boiler, and its efficiency rating.
Liquid propane is sold by the gallon, with the national average cost per gallon of propane at the end of November 2021 being $2.724. One gallon of propane produces 91,547 BTUs. To determine how much it costs to run your propane boiler for one hour, you need the number of BTUs your boiler produces and the cost of propane in your area.
Divide the number of BTUs your boiler produces by 91,547 to get the number of gallons of propane you use in one hour. A boiler that produces 200,000 BTUs uses 2.18 gallons of propane an hour. At a rate of $2.724, this boiler costs roughly $5.94 an hour to run.
Propane Combi Boiler
If you have a small home and use propane to heat both your home and your hot water, you may want to invest in a combi or combination boiler. These small boilers heat the water for hydronic heating on one side and the hot water you use for bathing or laundry on the other. They are meant to be space-saving and efficient and typically use condensing heat exchangers. They are often small enough to be wall hung and are meant for use in smaller properties such as condos, tiny homes, apartments, and houses smaller than 1,000 sq.ft. A combi boiler tends to be less expensive to run than a conventional boiler since it is typically smaller and more efficient.
While there are many advantages to a combi boiler, there are also disadvantages. You need a good main water pressure for the boiler to work appropriately. In addition, you are limited to how much water can run at once. For instance, you cannot have two showers going at once or run the tap while someone is in the shower. In addition, there is no immersion heater, so if the unit breaks down, you will not have hot water.
Combi boiler prices start at around $2,000 for very small units, with most having an average cost of about $3,000 and going up to around $10,000 for the most impressive units.
High-Efficiency Propane Boiler
Propane boilers come in a range of efficiencies, with the most efficient coming in at 98%. These boilers use stainless steel heat exchangers and are condensing units that help recover some of the heat from the exhaust, so they use less fuel. High-efficiency units are designed to trap any leaving heat and move it back for the condensing process. The basic idea is that heat is extracted so efficiently through the combustion process that the gases leave at a lower temperature and condense inside the heat exchanger. The cost of these boilers is between $3,000 and $8,000, depending on the size and model.
Outdoor Propane Boiler
Propane boilers come in different shapes and sizes. They can be used both indoors and outside. One of the reasons a homeowner might choose an outdoor unit is to retain more space in the house. However, installing an outdoor boiler may be more expensive because the boiler and piping need to be protected from cold temperatures. Insulation on the hot water pipes and boiler keeps heat inside and prevents freezing during the winter months. However, indoor boilers tend to be much more common. Installing an outdoor unit may be 10% to 15% more expensive due to extra work and materials.
Pros and Cons
Propane boilers have a number of benefits, but that does not mean there are no disadvantages to using them. One of the advantages over other boilers is that these boilers have very little odor associated with them, especially when compared to oil boilers. In addition, they are highly efficient. There is also no need to be connected to the electrical or gas grid to use these boilers. Finally, propane can be stored as a pressurized liquid, so there are few storage requirements.
On the other hand, installing a new propane boiler is more expensive than other boilers. Homeowners need to be aware of their fuel levels and reorder when needed. These units can also be less eco-friendly than electric or gas boilers. Other downfalls of these boilers include the need for a storage tank to hold propane and a requirement for regular maintenance and servicing.
Maintenance
Propane boilers are relatively low maintenance, only requiring service once every few years. This service costs between $50 and $200 per visit, depending on whether or not any parts need to be replaced to help keep your boiler running efficiently. This process involves looking for leaks, checking the pressure, and inspecting the thermostat. Parts will be inspected and cleaned, and a test will be run to ensure all parts are functioning correctly.
The only maintenance you may need to perform regularly is occasionally flushing the system to remove any sediment inside the line and refilling with fresh water. Regular maintenance is essential to keep a propane boiler in top shape. When not maintained, the unit may experience wear and tear. This decreases the lifespan of the boiler.
Manual J Calculation
To truly determine what the best size boiler is for your home, your HVAC technician performs a Manual J calculation. This formula takes into account the square footage of your home, your climate zone, how much insulation your home has, and any other energy-saving features. This gives you the most accurately sized boiler for your home, so trust that you are not overpaying in energy bills.
Propane Boiler vs Oil Boiler
If you live in an area of the country where natural gas is unavailable, you have a choice of either oil or propane for heating your home. Both are delivered to your home and stored on your property in tanks. Of the two, propane tends to be less expensive to purchase, although oil burns hotter, so you use less of it each day.
Oil boilers tend to be higher in maintenance than propane boilers because the soot produced by the oil often clogs the lines and needs to be cleaned out regularly. Propane burns cleaner, with fewer particulates, which means that it is better for the environment and less likely to clog your lines. The average cost for a propane water boiler ranges from $3,800 to $12,000. An oil boiler costs $4,000 to $9,000 installed. However, it only reaches roughly 91% efficiency, so while it may be less expensive to install, it costs more in fuel monthly.
| Type | Average Cost (Installed) |
|---|
| Propane | $3,800 - $12,000 |
| Oil | $4,000 - $9,000 |
Electric Boiler vs Propane Boiler
Another choice for homes that do not have natural gas is an electric boiler. Electric boilers use electricity to heat the water. With installation, these boilers cost about $1,500 to $9,000. Due to the high cost of electricity, though, they are often smaller and used primarily in zones 1 and 2, where not much heat is needed. They are a good choice for home additions, where the addition needs a different heating system than the rest of the house.
However, if you live in a moderate or cold climate and want to use a boiler to heat your whole house, propane is the better choice. A propane boiler typically costs $3,800 to $12,000 for the unit and installation. Propane boilers are larger, hold more water, produce more heat, and cost less to run.
When comparing the two types of boilers, electric boilers need only an electrical supply, making them ideal for remote locations. However, the heating capacity is lower than with a propane boiler. Propane boilers are typically less expensive to run but can be more complicated to install. Electric boilers are smaller, less expensive, and have fewer moving parts, but gas boilers come in larger numbers and have greater power.
| Type | Average Cost (Installed) |
|---|
| Electric | $1,500 - $9,000 |
| Propane | $3,800 - $12,000 |
Enhancement and Improvement Costs
Boiler Insulation
Adding insulation to your boiler reduces energy costs by slowing the amount of heat lost by the boiler. Insulation costs between $50 and $100. Insulating a boiler ensures the unit can quickly and easily heat up to save both money and time. In addition, it increases water temperatures by two to four degrees.
Wall-Mounted Propane Boiler
If you have a lighter aluminum or stainless steel boiler, it is likely wall mounted to save space. Many boilers today are available as wall-mounted units. They have costs starting at $4,000. Some of the main benefits of a wall-mounted unit are compact dimensions, excellent efficiency, and comfort. These boilers are also less likely to create flooding issues.
Programmable Thermostat
Another way to get a good handle on your energy costs is to install a programmable thermostat, which automatically reduces your boiler usage when you are not at home. A programmable thermostat costs between $30 and $150 without installation costs.
Generator
If the power goes out, your boiler’s motor stops working. For this reason, you may want to invest in a portable generator to keep your boiler working. They have starting costs of around $600. These generators typically run on diesel or gas, although some propane and natural gas models exist. Your location, the size of your home, and how many devices and appliances you wish to power will determine the generator size that is right for your home. Portable generators are less expensive than stand-by generators and work well for occasional loss of power.
Additional Considerations and Costs
- Location. In most areas, you need a permit to have a boiler installed in your home. Check with your local town or city hall for more information.
- Energy efficiency. Before installing a new boiler, consider increasing your home’s energy efficiency with insulation and a new thermostat.
- Home installation. Install your boiler inside your home rather than in an unheated area, so it does not need to work as hard. This saves you money on energy bills.
- Cooling options. While boilers heat your home efficiently, they do not offer cooling. If you want to add cooling, you need to install a separate air conditioner. With installation included, the average cost is $2,000 to $9,000.
- Propane prices. In some areas, propane prices may be lower in the summer months. Because propane is stored on your property in tanks, top off your tanks during this time to save money for the upcoming winter.
- Environmentally friendly. Propane produces fewer greenhouse gasses than other fuels, making it a more environmentally friendly option.
- Conversion kits. Many brands that make gas boilers also make LPG boilers or create units that use either gas or LPG with no conversion kits necessary. In addition, any gas unit may be converted to an LPG boiler for an additional $25 to $100 kit, which means you have a lot of options for the brand and manufacturer of your propane boiler.
FAQs
- Are propane boilers efficient?
Propane boilers are extremely efficient, with modern models rating about 90 to 98% efficiency. The boilers provide even, comfortable, consistent heat in even the coldest seasons.
- How much is a propane boiler for a house?
Propane gas boiler prices vary from $1,200 to $8,000 for the heating unit alone. When considering installation costs, the total ranges from $3,800 to $12,000.
- Is it cheaper to heat with propane or oil?
It is generally less expensive to heat with propane than with oil. However, this depends on your location and climate. Propane tends to be more efficient as a heating fuel than oil.
- How much propane does a boiler use?
This depends on the number of BTUs your boiler produces. One gallon of propane is equal to 91,547 BTUs. Larger boilers use more propane than smaller boilers.
- What are the disadvantages of propane?
Propane is expensive and must be stored in tanks on your property. Those tanks leak and become a fire risk.
- How long will 100 gallons of propane last?
This depends on the number of BTUs your boiler or furnace uses and how often you run them. One gallon of propane is equal to 91,547 BTUs. Larger appliances use more propane than smaller appliances.
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