Natural Gas and Propane Furnaces

Keep an eye out for these "red flags" that indicate your furnace is nearing the end of its life:

Rising Energy Bills: Your system has to work harder and longer to produce the same amount of heat.

Frequent Repairs: If you’ve called a technician more than twice in the last two years.

Strange Noises: Banging, rattling, or squealing sounds often indicate mechanical failure.

Uneven Heating: Some rooms are freezing while others are stifling.

Yellow Burner Flame: A healthy gas flame should be blue. A yellow or flickering flame can be a sign of incomplete combustion or carbon monoxide.

The primary difference is the fuel source and the way it is delivered to your home. Natural gas furnaces connect directly to a municipal utility line, providing a constant supply of fuel. A propane furnace uses fuel stored in a pressurized tank on your property.

Most residential gas furnaces are manufactured to run on natural gas by default. However, almost all of the units we sell can be easily converted to propane using a simple, brand-specific "LP Conversion Kit."

These terms describe the direction in which the heated air is pushed through the unit:

Natural gas upflow furnace: Air is drawn in at the bottom and blown out the top. These are common in basements.

Downflow furnace: Air is drawn in at the top and blown out the bottom. These are typically found in homes built on concrete slabs or in utility closets.

Horizontal gas furnaces: These units lie on their side and push air left-to-right or right-to-left. They are the go-to choice for attics or crawlspaces where vertical clearance is limited.

Many modern units are "multi-positional," meaning they can be configured for several of these orientations.

Sizing a furnace is measured in BTUs (British Thermal Units). A unit that is too small won't heat your home on the coldest days, while an oversized unit will waste energy and wear out quickly. Generally, you need about 30–60 BTUs per square foot, depending on your climate zone and insulation. For a precise match, use our Sizing Tool or consult a professional to ensure your new natural gas furnace is perfectly calibrated for your space.

Yes! Under the Inflation Reduction Act, many high-efficiency residential gas furnaces (specifically those with an AFUE rating of 97% or higher) qualify for federal tax credits. Additionally, many local utility companies offer instant rebates for upgrading to energy-efficient equipment. We recommend checking the Energy Star website and your local utility provider to see how much you can save on your ac and furnace replacement.

Most natural gas furnaces have a lifespan of 15 to 20 years. If your unit is approaching the 15-year mark, it is wise to start planning for a replacement before an emergency breakdown occurs. Newer models are significantly more efficient, meaning a modern furnace ac system can often pay for itself through lower monthly utility bills.

Yes. Installing natural gas furnaces or a propane furnace involves working with high-voltage electricity, specialized venting, and flammable gas lines. To ensure the safety of your family and to keep your manufacturer warranty valid, all equipment must be installed by a licensed HVAC professional.

The right furnace size depends on your home's square footage, your local climate, and your insulation levels. As a general rule, smaller homes or well-insulated spaces do great with our 40,000 BTU furnaces or 60,000 BTU furnaces. Medium-sized homes typically require 80,000 BTU furnaces or 100,000 BTU furnaces. For large homes, commercial spaces, or extreme cold climates, you will want to look at our heavy-duty 120,000 BTU furnaces and maximum-capacity 140,000 BTU furnaces. If you are unsure, you can always use our free Sizing Tool or contact our HVAC experts for guidance!