How Much Is the Cost of a Propane Boiler?

Average Propane Boiler Costs

What Is a Propane Boiler?

A propane boiler runs on propane or liquid petroleum gas (LPG). The propane is mixed with air and burned to produce heated gases that travel to the heat exchanger. There, the heat transfers to pressurized water until it's needed. Depending on the boiler type, it either stays as water or gets turned into steam. And when necessary, it's released to raise the ambient temperature. 

Propane boilers are larger than electric models, cost less to run, and provide more heat. Electric boilers cost less than propane, but their increased running costs offset these up-front savings. Propane boilers are also more efficient than oil models, which only reach around 91% efficiency. Oil boilers cost more to run than propane models and are considerably less environmentally friendly.

According to the U.S. Department of Energy's Office of Energy Efficiency & Renewable Energy, the boiler you select should be sized for your home's square footage and your U.S. climate zone (not to be confused with the U.S. Department of Agriculture's hardiness zones). The table below shows each climate zone's recommended boiler size measured in British thermal units (BTU) per square foot.

Propane Gas Boiler Cost by Heating Method

Both hot water and steam propane boilers heat your home, but they do it differently. Hot water models are less costly than steam boilers, but they're longer lasting and more efficient.

Hot Water

Hot water propane boilers cost between $3,800 and $9,500 with installation, with most people spending around $6,650. They're the most cost-friendly option. Plus, they're quiet and inconspicuous. But they don't last as long as their steam counterparts, and they're less efficient. 

In a hot water system, heated water travels through radiators or radiant heating systems to release heat into the home before passing back through the boiler to pick up new heat in a continuous loop. 

Steam

For steam propane boilers, expect to pay between $5,100 and $12,000 with installation, with most people spending around $8,550. Steam boilers command a higher up-front cost than hot water models, but they're more efficient and have a longer life span, making them the more economical choice over the long term. 

In a steam system, water is vaporized, then the steam moves to upright radiators to transfer its heat. As the steam cools, it condenses and travels back to the boiler in a closed loop, where it’s once again pressurized and heated.

Propane Boiler Cost by Boiler Type

Whether you choose a condensing or non-condensing boiler impacts up-front and running costs and longevity. Condensing boilers are more expensive and efficient but only last for a short time compared to standard or non-condensing models.

Condensing

Condensing propane boilers cost between $5,600 and $12,000, with most people spending around $8,800, including installation. While the most expensive option, condensing models are also the most efficient. Condensing boilers can reach up to 98% efficiency and have comparatively low running costs. However, they don't last as long as standard boilers, so they cost more overall. 

Non-Condensing

Installing a non-condensing propane boiler costs between $3,800 and $8,000, with the average homeowner spending about $5,900 for this job. Although these models cost less to install than condensing boilers, they have higher running costs since their efficiency typically sits between 80% and 94%. They also have a longer life span. A non-condensing boiler has a higher carbon footprint based on monthly energy consumption, so its longevity goes toward offsetting the higher energy usage.

Propane Boiler Cost by Material

Which metal you choose for your heat exchanger significantly impacts prices. Cast iron is the most affordable, while stainless steel costs the most. However, cast iron also has the longest life span. Each material has specific attributes and best-use cases.

Cast Iron

Ranging from $3,800 to $7,000, propane boilers with a cast-iron heat exchanger have an average price of $5,400. Cast iron is the heaviest material but also the most affordable. And it's the longest lasting, with a projected life span of 30 years or more. 

Aside from the weight, which means that you can't use it in wall-mounted models, the only other drawback to cast iron is that it's not as efficient when transferring heat as the other options, so it isn't used in condensing boilers. Generally, cast-iron heat exchangers achieve up to 85% efficiency.

Aluminum

Propane boilers with an aluminum heat exchanger cost between $5,100 and $7,500, with most people paying $6,300, including installation. Aluminum is the lightest option and is popular with people who want wall-hung boilers. These heat exchangers can reach 94% efficiency, which is better than cast iron but still not high enough to be used in condensing boilers. Aluminum is a good middle ground between value, longevity, and efficiency, with an estimated life span of up to 15 years.

Stainless Steel

Expect to pay between $5,600 and $12,000 for a propane boiler with a stainless-steel heat exchanger, with a typical price of $8,800, including installation. Stainless steel is lightweight and well-suited to wall-mounted boilers. Additionally, it's the most efficient option for transferring heat, with an efficiency of up to 98%. 

Stainless steel heat exchangers are generally only used in condensing boilers because they can withstand the high-acid condensate that corrodes metal better than other options. However, even stainless steel eventually corrodes with constant exposure to the acidic condensate, so warranties typically last around seven years, even though the projected life span is up to 15 years.

Propane Boiler Cost by Brand

Many popular brands make propane boilers, ranging from small, non-condensing low BTU models suitable for small homes in zones 1 and 2 to large, high-efficiency models with a large BTU output suitable for a large property in zones 6 and 7. Take a look at some of the most popular boiler brands and their typical prices in the table below:

Propane Boiler Cost Breakdown

The cost to install a propane boiler is split evenly between materials and labor. How much you'll pay depends on the size and type of boiler you choose and how complex the installation is. Switching like for like is the easiest option that costs the least. 

Materials

The cost of the boiler itself starts at around $1,200, but you can spend as much as $8,000 for a large-capacity, high-efficiency model. At lower price points, you'll find simple, non-condensing propane boilers with cast-iron heat exchangers, a hot water system, and moderate efficiency. At the other end of the scale, you'll find high-efficiency condensing boilers with stainless-steel heat exchangers and a steam setup. You'll also need to account for the cost of a propane tank if you don't already have one.

Labor

Expect to pay between $2,600 and $4,000 for a standard propane boiler installation. This is for a simple installation where the drain, exhaust, and fuel lines are already in place and are in good condition. If these need replacing or installation from scratch, you'll pay an additional $500 to $5,000, depending on the extent of the work involved. 

And if you don't have a propane tank, you'll need one. Installing a propane tank costs approximately $280 to $8,150, depending on the size, type, and location.

Other Propane Boiler Cost Factors

There are several other cost factors to consider when planning to install a new boiler, ranging from maintenance and general running costs to enhancements and extras. 

Running Costs

To work out the running cost of your boiler, you need to do a little math, and you need to know your home's square footage and the average propane price per gallon in your area, according to the U.S. Energy Information Administration. For example, 1 gallon of propane produces 91,547 BTUs. As of October 2022, the average price of propane in the U.S. is $2.66 per gallon. 

Let's say you have a standard 2,500-square-foot home in a moderate climate zone, like zone 4. To ensure you have enough capacity for the coldest days, let's say you go for the recommended output range of 40 BTUs per square foot. 

Multiply the square footage of your home by the recommended BTUs per square foot to get the total BTUs needed per hour. For example: 2,500 x 40 = 100,000 BTUs per hour. 

We know that 1 gallon of propane produces 91,547 BTUs. So, divide the required number of BTUs by the BTUs per gallon figure to find out how much we'll spend per hour. For example: 100,000 BTUs per hour / 91,547 BTUs per gallon = 1.09 gallons of propane per hour. Since the average U.S. price per gallon is $2.66, the equation is $2.66 x 1.09, or $2.90 per hour. 

Maintenance Costs

Maintenance costs are minimal if you keep on top of regular inspections and take care of any reported issues swiftly. Annual boiler services cost between $50 and $200. These inspections and tune-ups check for leaks, efficiency, changes in pressure, and thermostat efficacy. They're an important part of keeping your boiler in peak condition and reducing repair costs.

Enhancements

There's a range of enhancements you can choose for your boiler to help it better serve your household needs. We list some of them below:

• Smart thermostats cost: They’re around $200–$500 and optimize boiler usage and lower energy consumption.

• Insulation: It costs about $50–$100 to insulate a boiler, which lowers energy consumption and improves efficiency by reducing heat loss.

• Wall-mounting: Wall-mounted boilers cost around $6,500–$12,000. This is only possible with small, lightweight boilers but is a good space-saving option.

• Adding cooling: Propane boilers can't offer cooling, so you may need an AC. Installing central air conditioner costs around $5,900. 

• Natural gas to LPG conversion: Kits to convert natural gas boilers to LPG range from $25–$100, which saves money over the cost of installing a new boiler. 

DIY Propane Boiler vs. Hiring a Pro

Installing a propane boiler isn’t a DIY job. In many locations, you need permits and a suitable tradesperson license. It costs more, but the price of installing a gas boiler or propane boiler professionally is far less than the cost of repairs to your home if you do something wrong. 

Working with volatile substances like natural gas or propane should only ever be undertaken by professionals for the safety of your family and your property. In most cases, attempting to install a boiler yourself voids the warranty. Hire a local HVAC pro or boiler installer near you to handle the process safely and efficiently.