Dual Fuel Heat Pump Systems: Heat Pump and Furnace Combos from 1.5 to 5 Ton

A dual fuel heat pump system—also called a hybrid heat pump or dual fuel heating system—pairs an inverter-driven heat pump with a gas furnace on a single thermostat. The heat pump runs as the primary source during mild weather. When outdoor temperatures fall below the balance point, the thermostat switches automatically to the gas furnace, delivering reliable high-capacity heat when heat pump efficiency and output begin to decline in extreme cold. 

A heat pump and furnace pairing gives you the efficiency of electric heat transfer for the majority of the heating season and the raw output of gas combustion for the handful of nights each year when temperatures drop significantly. A heat pump with gas furnace backup, properly matched and pre-engineered, outperforms either unit running alone in climate zones 4 through 7. Unlike a heat pump furnace combination configured after the fact from separate components.

AC Direct stocks 451 Goodman dual fuel systems from 1.5 to 5 ton, with heat pumps rated from 15.5 to 17.5 SEER2 and furnaces available in 80%, 96%, and 97% AFUE configurations. Every heat pump and furnace combo ships free on orders over $1,500 with a 10-year factory warranty. If you are searching for dual fuel HVAC systems, a heat pump with gas furnace, or a heat pump furnace combination that comes pre-matched—this is the catalog. Browse by tonnage, furnace BTU, AFUE, and configuration using the filters above, or call 1-866-862-8922 for sizing guidance.

Why a Dual Fuel HVAC System Outperforms Either Unit Alone

A straight cool AC with a gas furnace is reliable but misses the efficiency advantage of heat pump operation during the 70% of heating hours when outdoor temperatures stay above the balance point. An all-electric heat pump is exceptionally efficient in mild weather but leans on expensive electric resistance strips when temperatures drop below 25 to 30 degrees Fahrenheit—which spikes winter electricity bills. A heat pump with gas furnace solves both problems in a single heat pump furnace combo: heat pump efficiency for most of the season, furnace power for the coldest nights.

A heat pump dual fuel system eliminates both compromises simultaneously. The inverter heat pump handles cooling all summer and heating through fall and most of winter at 2 to 3 times the efficiency of electric resistance heat. The gas furnace takes over automatically on the coldest nights at lower operating cost than electric strips. Buyers searching for dual fuel HVAC systems consistently find this heat pump furnace combination delivers the lowest annual energy cost of any HVAC configuration in climate zones 4 through 7.

The Balance Point: The Setting That Makes the System Work

The balance point is the outdoor temperature at which your thermostat switches from heat pump operation to gas furnace operation. It is the most important setting on a dual fuel heat pump and the one most likely to be misconfigured at installation.

Set too high—say, 40 degrees Fahrenheit—the furnace fires on nights that the heat pump could handle efficiently, burning more gas than necessary. Set too low, the heat pump struggles near its capacity limit before the furnace takes over, reducing comfort and efficiency. The correct balance point depends on three variables: your local electricity rate versus gas rate, your heat pump's rated low-ambient performance, and your home's insulation quality. For most Goodman inverter systems in climate zones 4 and 5, a balance point between 30 and 35 degrees Fahrenheit is appropriate. Your installer programs this on the thermostat at commissioning.

For a full breakdown of how the balance point affects operating cost across different climates, see Heat Pump vs. Gas Furnace: The Balance Point in Freezing Weather.

Choosing the Right Furnace BTU and AFUE for Your Dual Fuel System

The heat pump tonnage sizes for your cooling load. The gas furnace sizes for your heating load. They are separate decisions—and the furnace filter on this page has two independent variables that buyers regularly get stuck on.

Furnace BTU Capacity

Use 25 to 30 BTUs per square foot for mild to moderate climates, and 35 to 50 BTUs per square foot for colder climates with heavy heating demand.

AFUE: 80%, 96%, or 97%

AFUE is the percentage of gas fuel converted to usable heat. In a dual fuel heating system, the furnace only fires during the coldest periods—it does not run all winter the way a furnace-only system does. This affects the payback math on high-efficiency AFUE.

• 80% AFUE: Right choice for mild climates (zones 1-4) where the dual fuel furnace fires infrequently. Lower upfront cost, acceptable efficiency given limited runtime.
• 96% AFUE: Right choice for cold climates (zones 5-6) where the furnace will see significant operating hours. The premium pays back in 3-5 years through reduced gas consumption.
• 97% AFUE: Maximum efficiency tier—best for climate zone 7 or homeowners with high gas rates who want every BTU of fuel converted to heat.

Sizing Your Dual Fuel Heat Pump System: Tonnage by Square Footage

Match heat pump tonnage to your cooling load first—that is the primary sizing constraint. In very cold climates where the heating load exceeds the cooling load, a licensed HVAC technician may recommend sizing up one step.

Figures assume 8-foot ceilings and standard climate. Use the AC Direct AC sizing calculator for a climate-adjusted recommendation before purchasing.

Need help sizing? Use the AC sizing calculator or the furnace sizing guide before selecting a system.

Goodman Dual Fuel Systems: Inverter Heat Pumps + 2-Stage Gas Furnaces

Every heat pump furnace combo in this catalog is a Goodman system—one of the most widely installed residential HVAC brands in the United States. Goodman dual fuel HVAC systems are built around inverter-driven heat pump condensers that typically modulate output between approximately 30% and 100% of rated capacity, depending on the model. This matters for any heat pump dual fuel system: an inverter heat pump stays efficient much closer to the balance point temperature than a single-speed unit, which means the gas furnace fires less often and your gas bill stays lower.

Goodman furnace sections in this catalog are all 2-stage variable-speed configurations—running at reduced capacity on moderate cold days and stepping to full output only when conditions demand it. This reduces cycling noise, improves humidity control, and extends the furnace's service life by reducing mechanical stress. All systems carry a 10-year parts and compressor warranty when registered by a licensed HVAC contractor.

Heat Pump with Propane Backup: The Option for Rural Homes

For homes without access to a natural gas line, a heat pump with propane backup delivers the same dual fuel performance using an LP propane furnace instead. This heat pump furnace combo with propane operates identically to a natural gas heat pump dual fuel system—the thermostat switches between heat pump and furnace at the same balance point, the efficiency advantage is the same, and the only difference is the fuel source. All Goodman gas furnaces in this catalog support propane conversion through a field-installed LP conversion kit. Browse propane conversion kits compatible with Goodman furnaces.

Dual Fuel Heat Pump Cost at AC Direct

Dual fuel heat pump cost at AC Direct ranges from $6,000 for a 3-ton 16 SEER2 system with a 60,000 BTU 80% AFUE furnace to $8,000 for a 5-ton 15.5 SEER2 system with a 100,000 BTU 80% AFUE downflow furnace. The dual fuel heat pump cost includes the matched inverter heat pump condenser and gas furnace as a pre-engineered system—not separately sourced components requiring individual compatibility verification.

Higher SEER2 ratings and 96-97% AFUE furnace sections carry a premium of approximately $500 to $1,200 over the base configuration at the same tonnage. Installation labor adds $2,000 to $4,000, depending on region and complexity. AC Direct offers 0% EZ Pay financing for qualified buyers and free shipping on all orders over $1,500.

California Buyers: Low NOx and Ultra Low NOx Configurations

California Air Resources Board regulations require gas furnaces sold in most California air quality management districts to meet Low NOx or Ultra Low NOx emissions standards. Standard Goodman furnace configurations do not meet California requirements. AC Direct stocks dedicated Low NOx and Ultra Low NOx dual fuel heat pump system configurations specifically for California buyers use the California subcategory filter above to ensure the system you select is compliant for your district before purchasing.

Frequently Asked Questions

1. What is a dual fuel heat pump system?

A dual fuel heat pump system pairs an electric heat pump with a gas furnace on a single thermostat. The heat pump operates as the primary heating and cooling source during mild and moderate temperatures, delivering 2 to 3 times more heat per unit of electricity than electric resistance strips. When outdoor temperatures fall below the balance point—typically 30 to 40 degrees Fahrenheit—the thermostat switches to the gas furnace automatically. For a detailed explanation, see Hybrid Heat Pump Systems: The Best of Both Worlds.

2. What is the difference between a hybrid heat pump and a standard heat pump?

A standard heat pump uses electric resistance strips as backup heat when temperatures drop below its efficient operating range. A hybrid heat pump—also called a dual fuel system—replaces those strips with a gas furnace. The gas furnace provides stronger heat output at lower operating cost than electric resistance during cold snaps, which is the primary reason homeowners in climate zones 4 through 7 choose the hybrid configuration over an all-electric heat pump.

3. How does the heat pump and furnace combo know when to switch?

A dual fuel thermostat monitors outdoor temperature continuously and switches between the heat pump and gas furnace based on the programmed balance point. Above the balance point, the heat pump runs. Below it, the furnace fires. The balance point is set by the installer at commissioning and can be adjusted based on local energy prices and the homeowner's comfort preferences.

4. What size dual fuel heat pump system do I need?

Size the heat pump tonnage for your cooling load: approximately 20 BTUs per square foot for a well-insulated home in a moderate climate, 25 BTUs for average construction, and 30+ BTUs for poor insulation or a hot climate. Size the furnace BTU for your heating load: 25 to 30 BTUs per square foot for mild climates, 35 to 50 BTUs for cold climates. The two sizing decisions are independent—a 3-ton heat pump does not require a 3-ton equivalent furnace.

5. How much does a dual fuel heat pump cost?

Goodman dual fuel heat pump systems at AC Direct range from $6,008 for a 3-ton 16 SEER2 system with a 60,000 BTU 80% AFUE furnace to $7,998 for a 5-ton 15.5 SEER2 system with a 100,000 BTU furnace. Higher-efficiency 96% and 97% AFUE furnace configurations add $500 to $1,200 to the base price at the same tonnage. Total installed cost including labor typically runs $8,000 to $12,000 for most residential applications.

6. Should I choose 80%, 96%, or 97% AFUE for my dual fuel furnace?

In mild climates where the dual fuel furnace fires infrequently—zones 1 through 4—80% AFUE is a cost-effective choice. The limited furnace runtime means the efficiency premium of 96% AFUE takes many years to pay back. In cold climates—zones 5 through 7—where the furnace operates regularly during winter, 96% or 97% AFUE pays back its premium within 3 to 5 years through reduced gas consumption. Choose based on how many hours per year your furnace will actually run.

7. Can I use a heat pump with propane backup instead of natural gas?

Yes. Many Goodman furnaces in this catalog support LP propane conversion through a field-installed conversion kit. A heat pump with propane backup delivers the same dual fuel performance as a natural gas configuration, making it the right choice for rural homes without gas line access. Your installer purchases and installs the propane conversion kit at the time of installation.

8. What is the balance point on a dual fuel system, and how is it set?

The balance point is the outdoor temperature threshold at which the thermostat switches from heat pump to gas furnace operation. It is typically set between 30 and 40 degrees Fahrenheit and is programmed by the installer on the dual fuel thermostat at commissioning. Setting it correctly for your local electricity and gas rates is one of the most impactful steps in maximizing the system's annual energy savings.

9. Why does AC Direct only carry Goodman dual fuel systems?

Goodman is the largest supplier of residential dual fuel heat pump systems in the United States and offers the broadest compatible lineup of heat pump condensers and 2-stage gas furnaces across all standard tonnages. The pre-engineered Goodman dual fuel systems in this catalog are verified compatible combinations—not field-assembled pairings—which simplifies installation and protects the factory warranty.

10. Are Goodman dual fuel systems eligible for federal tax credits?

The federal Section 25C tax credit of up to $2,000 per year applied to qualifying heat pump installations through December 31, 2025. As of the current tax year, buyers should verify current federal incentive eligibility at Energy Star or consult a tax professional. Many utility companies and state programs continue to offer rebates on high-efficiency heat pump systems independent of the federal credit—check with your local utility before purchasing.

Free shipping over $1,500. 10-year factory warranty. 0% financing available.

Browse dual fuel heat pump systems above, or explore related categories: AC heat pump split systems, AC gas heat split systems, and gas furnace components. Questions? Call 1-866-862-8922.