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How to Choose a Propane Garage Heater

If part of your garage is a workshop or hobby space, you want it to stay warm and cozy no matter what time of the year it is. However, that’s easier said than done, since insulating the whole space is expensive. At the same time, piping in heat from the home’s central heating is not cost-effective, for a space you don’t occupy all the time.

This is where propane garage heaters come in. 

In this guide, we discuss what propane heaters are, their pros and cons over electric and natural gas heaters, and how to choose the right one for your garage.

What are Garage Heaters?

As the name suggests, garage heaters are heating devices specifically designed to warm your indoor garage. They come in two designs:

Portable garage heater – these are smaller heaters that either sit on the floor or table. They can be repositioned or even moved to different areas of the house where needed, but have a smaller heating capability.

Fixed garage heater – these are larger units that are permanently fixed. While they are not mobile, they have a larger heating capacity and are usually more efficient.

What are Propane Garage Heaters?

There are three power sources for garage heaters: electric, propane and natural gas. 

Propane and natural gas garage heaters are very cost-efficient, but require more space and maintenance. Electric garage heaters are less efficient, but come in a compact size and require less cleaning and maintenance.

Propane garage heaters are ideal for:

  • Larger garages
  • Garages with a higher ceiling over the standard 8-foot height
  • Homes without a natural gas service line
  • Homes located in colder climates

Types of Propane Garage Heaters

There are three main types of propane garage heaters, based on heating technology:

Forced air gas heaters – these actively draw in cold air with a fan, heat it, then distribute the warm air throughout the garage.

Convection gas heaters – these are more economical by only heating the air immediately surrounding the unit. Since hot air naturally rises, it works by heating the colder air that sinks back down to the heater. While they cost less to run, they take more time to heat up the garage and are the least efficient model of the three.

Wall-mounted blue flame – these radiator-type heaters save space by mounting to a wall. The blue flame burns at 99.9% efficiency and heats the air surrounding the unit. Some radiant heaters do not use a fan or any air circulating mechanism, which cuts down on complexity and possible points of failure.

Direct Vent vs Ventless Propane Heaters

Direct vent or vented propane heaters use an exhaust pipe or vent to expel the fumes produced by the propane combustion safely to the outside. They are economical, but require a duct to the outside.

Vent-free or ventless propane heaters, which include infrared and blue flame heaters,  produce a limited amount of exhaust. They are cheaper to install since they don’t require ductwork, and are more flexible. However, they cannot be used in certain parts of the house, such as bedrooms, and some jurisdictions like California don’t allow them at all.

Propane vs Natural Gas: Which is Better?

The main difference between propane and natural gas as a fuel source for garage heaters is availability. Most locations only have the choice of one or the other. 

If you have natural gas available at your location, it will generally be more cost effective. On the other hand, natural gas doesn’t burn as hot as propane. 

Each gas type has different properties of burning and will require a heater set or converted for the particular fuel type you are using. Rest assured that regardless of which type of fuel is available to you, you will be able to heat your space effectively. 

Are Propane Heaters Safe?

One of the biggest concerns with using propane heaters in an enclosed space like a garage is carbon monoxide buildup.

Propane itself has a strong and peculiar odor – it’s easy to detect if propane is leaking. However, carbon monoxide is odorless and tasteless. When it builds up, it can push out the oxygen and cause suffocation and poisoning without occupants being aware of it.

Propane heaters are safe to use provided that:

  • There is sufficient ventilation for the exhaust pipe
  • There is enough combustible air to use as fuel
  • There is a carbon monoxide detector

How to Choose a Propane Garage Heater

These are the key features to look for when shopping for a propane garage heater:

BTU sizing

The heating capacity of heaters is measured in British Thermal Units (BTUs). This is the heat required to raise the temperature of one pound of liquid water by 1 degree Fahrenheit. 

Propane garage heaters can range from 10,000 all the way up to 100,000 BTUs. To determine the BTU capacity needed for your particular garage space, contact us for assistance.

Heating technology

Forced-air heater – these are able to blast a huge amount of direct heat, albeit in a limited direction. They are ideal if you wish to warm a specific part of the garage, such as a work table.

Convection heaters – since they radiate heat in a 360 arc, they work best if they can be placed in the center of the garage.

Wall-mounted heater – not as powerful as the other models, these usually top out at 30,000 BTUs. They offer the convenience of an electric heater without the need for an outlet. This makes them ideal for warming smaller garages and workshops.


Look for these safety features in a propane garage heater:

Low oxygen sensor – shuts the unit off in case of low oxygen levels or carbon monoxide buildup. (only needed for ventless heaters)

Overheating protection – ensures the heater doesn’t burn itself out, by using a sensor to detect dangerous temperatures.

Auto shutoff – this automatically switches the unit off in case the heater gets knocked over or suffers a short in the system.

Cool-touch exterior – typically found in portable and wall-mounted garage heaters. The heater body is made of fiberglass or plastic, making it safe to touch even during extended operation.

UL label – The Underwriter’s Laboratory (UL) certification means the heater follows modern safety and construction standards. 

Programmable thermostat

This allows the user to set a specific temperature via remote control or electronic keypad. This makes the heater more efficient by only activating to maintain the desired temperature instead of working full-blast all the time.

Build quality

To ensure long life, check the quality of the casing and major components. A good propane heater from a reliable brand uses a quality metal body, rubber tubes, and durable valves. When buying online, check the specs and the warranty period.

Installing a Propane Garage Heater

Both propane and natural gas garage heaters follow the same installation process. Start by choosing a location for the heater. Ideally, it should be placed where the heater’s fan can counteract the most heat loss in the garage. This way it’s able to warm the whole garage space more evenly.

Make sure the propane heater is placed on a non-combustible surface. It should have sufficient distance from curtains, furniture as well as other flammable items that may be stored in your garage such as paint and household chemicals. When installing a wall-mounted heater, check that the wall material and insulation are non-combustible.

Next, choose the proper gas pipe, connection, and joint compounds. As you lay down pipe, ensure the connections are secure, and not placed where foot traffic or household objects stored in the garage may dislodge or damage the piping.

You may also need an electrical outlet for the thermostat. Since some propane garage heaters don’t have a pilot light, they may use an electric spark to start up the unit. The thermostat typically takes up two breaker spaces in your main electrical panel. Since heat rises, the thermostat should be placed about 5 feet off the ground to provide the most accurate reading.

Practical Tips When Using a Propane Garage Heater

Never place anything on top of a propane heater, even if the heater has a cool-touch exterior.

Install a carbon monoxide detector in the garage for added safety.

Never leave the propane heater unattended for extended periods. Always check that the heater is off before going to bed.

Do not use spray cleaners, aerosol-based air fresheners, or spray paint near a propane heater.

If the blue flame heater has a yellow or orange flame instead of blue, this indicates that the gas is not burning properly. Switch off the heater immediately and call a professional contractor.

Our Recommended Gas Garage Heaters

Entry level:

HearthRite HRW17ML 16800 BTU Infrared/Radiant Vent Free Gas Heater

This budget vent-free heater is capable of up to 16,800 BTUs of radiant heat and operates at 99.9% efficiency. It comes with  an Oxygen Depletion Sensor (ODS) that will shut off the heater if the oxygen levels drop to an unsafe level.

Standard installation is wall mounting but an optional floor stand is available separately. Other optional accessories include a blower and thermostatic control unit.

HearthRite HRW17ML 16800 BTU Infrared/Radiant Vent Free Gas Heater - LP
Price: $372.00 HearthRite HRW17ML 16800 BTU Infrared/Radiant Vent Free Gas Heater - LP

The Hearthrite vent free heater with 16,800 BTUs will warm up your room like sun coming in from a window. A radiant or infrared heater adds warmth to the room a...

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Vented propane garage heater:

Sterling GG045A1NSA11 45,000 BTU Gas Fired Tubular Unit Heater

Sterling’s GG series heaters are all-in-one units that can be easily converted from standard combustion to separated combustion. A separated combustion unit is ideal for environments that are dusty, dirty or mildly corrosive, and climates with high humidity or negative pressures.

This low-profile garage heater is perfect for garages with low ceilings or limited headroom at only 13.25″ high. It is capable of 45,000 BTUs of heat with an 82% Thermal Efficiency Rating. Features include an easy to access control panel, a single-stage gas valve with direct spark ignition, high limit switch and air pressure switch. 

Air Inlet Kits are available separately and they allow for concentric venting through a single wall or roof opening. Standard combustion installation requires a vertical or horizontal venting, while separated combustion installations require the Air Inlet Kit for single wall (or roof) penetration. The tubular heat exchanger, constructed of heavy duty 20-gauge aluminized steel, is built to last and carries a 10-year heat exchanger warranty. 

DISCONTINUEDSterling GG045A1NSA11 45,000 BTU Gas Fired Tubular Unit Heater - Convertible Standard or Separated Combustion
Price: $1,305.00 DISCONTINUEDSterling GG045A1NSA11 45,000 BTU Gas Fired Tubular Unit Heater - Convertible Standard or Separated Combustion

The Sterling GG045A1NSA11 45,000 BTU Gas Fired Tubular Unit Heater is a low-profile garage heater. It is certified for use in non-occupied residential and comme...

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Ventless propane garage heater:

Rinnai FC824 22,000 BTU Vent Free Fan Convector Gas Heater

The FC824 is a great solution for hard to heat rooms. It uses a convection fan to evenly distribute the 22,000 BTUs of warmth throughout the room, with a low noise rating of just 44dB / 30dB (H/L) for quiet operation. 

It features modulating technology which includes a modulating gas valve and variable speed blower, which enables the furnace to use only the exact amount of propane needed to heat the space. This heater also includes Rinnai’s technology that constantly monitors the temperature so if a door opens and lets in cold air, it will be regulated automatically for your comfort. 

Safety features include a push button electronic ignition, which eliminates the need need for a standing pilot; Oxygen Depletion Sensor will disable the gas supply if the oxygen level in the room drops to unsafe levels; an overheat switch which will automatically shut down the unit if it exceeds a predetermined temperature; and a tilt switch that automatically disables the propane supply if the heater is knocked over, jolted or picked up while in use.

Rinnai FC824 24,000 BTU Vent Free Fan Convector Gas Heater - Choice of Fuel Type
Price: $1,026.00 Rinnai FC824 24,000 BTU Vent Free Fan Convector Gas Heater - Choice of Fuel Type

You may only know of Rinnai for their tankless hot water heaters but they also have an extremely efficient line of vent free fan convector gas heaters. The FC82...

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Premium propane garage heater:

Sterling HU050A1NS111 Nexus Series 50,000 BTU Gas Fired High Efficiency Condensing Unit Heater

The Nexus Series offers the highest efficiency ratings in the unit heater industry, offering ratings from 95% up to 99% efficient. This particular heater is the smallest in Sterling’s Nexus series, but don’t let its small size fool you: beneath its compact exterior lies a heater with a 97% efficiency rating, capable of 50,000 BTU input and 48,600 BTU output. 

The high efficiency rating is made possible by a unique tri-metal heat exchanger as well as a state-of-the-art combustion control system. The heat exchanger is constructed of a hybrid combination of stainless steel tubes and brass and aluminum fins for maximum efficiency, enhanced corrosion protection and thermal heat transfer. 

The Nexus line boasts auto-adjust altitude feature, which automatically regulates the air and fuel mixture with no loss of performance and requires no field adjustments. Nexus units also have both indoor and outdoor air reset modulation. Indoor air reset learns the needs of the space by constant monitoring and modulates accordingly, resulting in less cycling and lower fuel costs. Outdoor air reset functions in much the same manner, automatically adjusting and varying the indoor discharge air temperature based on the outdoor air temperature. Both functions offer a much more comfortable indoor environment while saving money in the long run. The outdoor air reset feature is most favorable in areas where there are daily temperature fluctuations, but is a great feature year round.

This model is field convertible to liquid propane (single orifice kit included) and Separated Combustion operation. Additionally, they are PVC/CPVC vent compatible. It can be installed as a single unit or set up as a multi-unit network, and includes ModBus communication for building automation without requiring additional control modules.

Sterling HU050A1NS111 Nexus Series 50,000 BTU Gas Fired High Efficiency Condensing Unit Heater - Convertible Standard or Separated Combustion
Price: $3,369.00 Sterling HU050A1NS111 Nexus Series 50,000 BTU Gas Fired High Efficiency Condensing Unit Heater - Convertible Standard or Separated Combustion

The Sterling HU050A1NS111 is the smallest unit in the NEXUS Series. It offers 97% efficiency rating with its 50,000 BTU input and 48,600 BTU output. The Nexus S...

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Mickey Luongo

Mickey is the resident heating and air conditioning expert with over 15 years of experience in the industry.

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