Heat Pump vs. Gas Furnace in Southern Utah: Which Wins?

If you live in Washington, Hurricane, or St. George and your furnace is creeping toward the end of its life, you are about to walk into a decision that has changed completely in the last five years. The question used to be “what brand of gas furnace?” Now the real question is “should I even install another furnace at all?”

Here is the short answer for Southern Utah: in almost every case, a modern heat pump beats a gas furnace on operating cost and comfort. Our climate is the textbook scenario heat pumps were designed for. Mild winters, occasional cold snaps, and a long cooling season where the same equipment also serves as your AC.

But many local homes still default to gas furnaces because that is what was installed 20 years ago. This article walks through the numbers, the climate science, and the cases where a furnace genuinely is the right call.

How each system actually works (90 seconds each, plain English)

A gas furnace is a controlled fire. Natural gas (or propane) flows into a sealed combustion chamber, ignites, and heats a metal heat exchanger to roughly 140°F. A blower pushes air across that heat exchanger and pumps the warmed air through your ducts. Combustion byproducts vent outside through a flue. Efficiency is measured as AFUE (Annual Fuel Utilization Efficiency). A 95% AFUE furnace converts 95% of the fuel’s energy into useful heat; the other 5% goes up the flue.

A heat pump does not create heat. It moves heat. Even at 30°F outside, the air still contains thermal energy, and a refrigerant cycle can extract it. The outdoor compressor pressurizes refrigerant; the indoor coil releases the captured heat into your air. In summer, the cycle runs in reverse and pulls heat out of the house. Efficiency is measured as COP (Coefficient of Performance) for heating and SEER2 for cooling. A modern heat pump runs at a COP of 3.0 to 4.0 in our climate, meaning every 1 unit of electricity produces 3 to 4 units of heat. That is how electric heat can be cheaper than gas: you are not generating energy, you are relocating it.

Learn more about how SEER2 ratings translate to real-world savings.

The Southern Utah climate advantage for heat pumps

Heat pump performance is governed by a concept called the balance point. That is the outdoor temperature at which the heat pump’s output exactly matches your home’s heat loss. Above the balance point, the heat pump alone keeps you warm. Below it, supplemental heat (electric resistance strips, or in dual-fuel systems, the gas furnace) kicks in to fill the gap.

For a properly sized cold-climate heat pump in a reasonably insulated Southern Utah home, that balance point sits somewhere between 15°F and 25°F.

Now look at the local climate data. St. George’s average January low is about 30°F. Washington and Hurricane track within a degree or two. We get maybe a dozen nights a year that dip below 20°F, and a true 15°F night happens a few times in a hard winter. The heat pump operates above its balance point for the overwhelming majority of the heating season. In Minnesota, you have to engineer around weeks of -10°F weather. In Washington County, you do not.

This is why heat pumps are the default new-construction heating system in Hurricane subdivisions built in the last several years. Builders ran the numbers and the math is not close.

Operating cost comparison

Let’s walk through the comparison for a typical 2,000 square foot Southern Utah home with a moderate insulation envelope, assuming the home needs roughly 40 million BTU of heating across a season (a reasonable estimate for our climate).

Gas furnace at 95% AFUE, burning natural gas at current Enbridge Gas rates: the furnace converts fuel to heat at 95% efficiency, so a fixed amount of gas gets burned to deliver that 40 million BTU across the season.

Heat pump at COP 3.5 average, running on local electric rates: because the heat pump moves 3.5 units of heat for every unit of electricity it consumes, it needs far less input energy to deliver that same 40 million BTU.

Running current utility rates through that math, the heat pump wins on operating cost by 15 to 20% even before you factor in the cooling-season savings from replacing an aging AC unit at the same time. With variable-speed equipment averaging closer to COP 4.0, that gap widens to 30%. And this comparison moves with utility rates; if natural gas spikes (as it did in 2022), the heat pump’s lead grows. Ask us for a current rate comparison specific to your home when we run your numbers.

Upfront cost: equipment and install

Be honest about this part. Heat pumps cost more up front.

In Washington County, here’s how the options stack up against each other for a 2,000 sf home, from least to most expensive:

• 95% AFUE gas furnace + matched 16 SEER2 AC condenser: the baseline
• Single-stage heat pump (15 SEER2, 8.1 HSPF2): a modest step up from the baseline
• Two-stage heat pump (16 SEER2, 8.5 HSPF2): a bit more than single-stage
• Variable-speed cold-climate heat pump (17+ SEER2, 9+ HSPF2): the biggest jump among the heat pump options
• Dual-fuel hybrid (heat pump + gas furnace + smart controls): the most expensive option, since you’re installing two complete systems

The heat pump premium is real, but smaller than people assume because you are replacing two pieces of equipment (furnace and AC) with one. Where a utility rebate applies, it narrows the gap further. Ask us for current numbers on your specific home; equipment and installation pricing moves with the market.

Utility rebates

Whether a rebate applies depends on who provides your gas and power. For homes with natural gas service, Enbridge Gas’s ThermWise program offers rebates on qualifying dual-fuel heat pump systems and on high-efficiency gas furnaces, so it can help whichever way you go. Some local power providers run programs of their own.

Rebate amounts and equipment requirements change, so we don’t list them here. When we quote your job, we check which programs your home qualifies for and provide the itemized invoice and equipment details the applications ask for. We quote heat pump installs across St. George and the surrounding service area.

See our heat pump installation services.

Comfort differences

This is the part most articles skip, and it matters more than people think.

A gas furnace runs short cycles of very hot air. It blasts on, dumps 140°F supply air for 10 minutes, and shuts off. Rooms heat fast but unevenly, and you feel temperature swings between cycles. Anyone who has stood under a register during furnace startup knows the feeling.

A heat pump runs long cycles of warm air, typically 95°F to 105°F supply temperature. That is cooler than your skin, so air coming out of a register can feel “drafty” if the airflow strategy is wrong. Done right (proper duct sizing, registers aimed correctly, variable-speed blower modulating to load), a heat pump produces the most comfortable indoor environment money can buy. Steady, even, no temperature swings, humidity better balanced because the equipment runs longer at lower output.

Heat pumps reward installation quality. This is why we will not install one without first verifying the duct system can support the longer, lower-velocity airflow.

When a furnace still wins

I said no hedging, so here are the actual cases where I will recommend a furnace:

1. Very low electric service capacity. Some older Southern Utah homes have 100A service that cannot accommodate a heat pump plus electric backup strips without a panel upgrade. If a panel upgrade is not in the budget, gas remains the practical option.
2. Off-grid or propane-only properties where electricity is generator-supplied and propane is already on site. The math flips because per-BTU electricity costs more than utility-supplied power.
3. New construction with already-stubbed gas service and a buyer who will own the home only 3 to 5 years. Payback math leans toward the cheaper-up-front option.
4. Fuel cost spike protection for very cost-sensitive owners. If you are deeply concerned about future electricity rate increases more than gas increases, gas hedges that risk. (Historically, this has not been the right bet, but it is a defensible position.)

That is the list. Notice “it gets cold here sometimes” is not on the list. Our cold is not cold enough.

Hybrid (dual-fuel) systems

A dual-fuel system pairs a heat pump with a gas furnace and a smart thermostat that switches between them based on outdoor temperature. The heat pump handles the work down to roughly 25°F to 35°F (whatever the economic crossover point is for your utility rates), and the furnace takes over below that.

For Southern Utah, this is overkill in most cases. A standard heat pump already handles 95% of our heating hours by itself, so the furnace in a hybrid setup might run 50 hours a year. That is a lot of equipment to install for marginal benefit.

Dual-fuel makes sense when:

• You already have a working gas furnace that is less than 7 years old and you want to add cooling/efficiency by installing the heat pump alongside it.
• You have a large or poorly insulated home where the load on the coldest nights truly exceeds heat pump capacity.
• You travel and want belt-and-suspenders heating reliability when no one is home to notice a problem.

Otherwise, a straight heat pump install is simpler, cheaper to maintain, and equally comfortable.

Bottom line: which to pick

Here is the decision tree we actually use during in-home consults:

• Existing gas furnace, 15+ years old, AC also aging: Replace with a heat pump. Single best move in HVAC right now.
• Existing gas furnace, under 7 years old, AC failing: Install a heat pump alongside the furnace as dual-fuel. Keep the working asset, gain the efficiency.
• No existing gas service: Heat pump, no question. Do not run a new gas line for a furnace in 2026.
• All-electric home with old electric resistance furnace: Heat pump. Your operating cost will drop by 60% or more.
• New construction: Heat pump unless the builder has already trenched gas and you genuinely prefer combustion heat.
• Geothermal-suitable lot (acreage, willing to invest): Look at geothermal heat pumps. Even better COP, longer equipment life, premium upfront cost.

For nearly every Washington, Hurricane, and St. George homeowner replacing aging equipment, the answer is a heat pump.

Get an honest assessment from M&M Mechanical Inc.

We have been installing heating systems in Washington County since 1992. We installed gas furnaces for 30 years and we still install them when they are the right call. But the technology and the economics have shifted, and we are not going to recommend a furnace just because that is what we have always done.

If your furnace is on its last legs, or you are just curious what your specific home would look like on a heat pump, we offer free in-home assessments. We measure your ducts, run a Manual J load calculation, look at your panel, pull your last 12 months of utility bills, and give you an itemized written quote covering both options. No pressure, no upsell. You get the numbers, you make the call.

Call (435) 674-1275 or stop by our office at 1430 Rio Virgin Drive, Washington, UT 84780. We can usually schedule an in-home visit within a week.

Already maintaining the system you have? Make sure you are on a year-round HVAC maintenance schedule so it goes the distance. And if you want to dig deeper into our heat pump installation process or full heating service offerings, those pages cover the specifics.