Which is Right For You?
Dual fuel is the better answer for most Denver homes: keep the gas furnace, add a cold climate heat pump, and set where the furnace takes over. All-electric only makes sense with prep (solar, batteries, air sealing). The changeover, typically about 25°F, is a setting, not a limit of the equipment.
If you are asking whether a heat pump is gas or electric, start with our guide to what a heat pump is.

What are heat pumps?
A heat pump moves heat instead of generating it. In winter it pulls warmth from outdoor air into your home; in summer it reverses to cool. All heat pumps run on electricity. For the full breakdown, see our guide to how heat pumps work.
The “dual fuel vs. fully electric” question is not about the heat pump itself. It is about what backs it up. Dual fuel pairs the heat pump with a gas furnace. Fully electric pairs it with an air handler and electric heat strips. Same heat pump, different backup.

Dual fuel heat pump systems

A dual fuel heat pump (also called a hybrid system) pairs a cold climate heat pump with your gas furnace. The heat pump runs as the primary heating and cooling source. When the outdoor temperature drops below the changeover point you set on the thermostat, the system runs the furnace instead.
At Xcel's October 2026 rates, gas heat from a 95% furnace costs the same or less than heat pump heat at every outdoor temperature, so a heat pump won't lower the winter bill in a gas home. Dual fuel gives you cooling, the heat pump rebates, and two ways to heat. Raise the changeover and gas does more of the heating; if rates change, you move the setting.
Dual Fuel Features
- Gas furnace runs below the changeover setting
- 50%+ of heating hours electrified
- Switch between fuels automatically
- Changeover typically set near 25°F (a cost setting, adjustable)
- Requires gas line and furnace
Fully electric heat pump systems

A fully electric system uses a cold climate heat pump for all heating and cooling, backed by electric heat strips (5-10kW) in an air handler. No gas, no furnace. Models like the Mitsubishi Hyper-Heat maintain about 80% heating capacity down to -13°F, which covers all but a handful of Denver nights per year.
The heat strips are not the primary heat source. They supplement during defrost cycles and on the coldest nights. All-electric works best in a home that has been prepped for it: solar panels, battery storage, and air sealing so the heat pump is not fighting a leaky envelope. With that prep, the operating cost premium mostly disappears. Without it, expect higher winter heating bills than dual fuel; if that is already happening in your house, see why an electric bill runs high with a heat pump.
Fully Electric Features
- Air handler with electric heat strip backup
- Cold climate rated: heats to -13°F and below
- No combustion, no gas line needed
- Pairs with solar + battery storage
- Single fuel source (electricity only)
The defrost cycle
When frost builds up on the outdoor coil, the heat pump reverses briefly to melt it - running like an AC for a few minutes. During that time, your vents blow cooler air. Backup heat (gas furnace or heat strips, depending on your system) kicks in automatically to keep your home comfortable.

Defrost cycles are automatic and typically last 2-10 minutes. They happen more often in wet, near-freezing conditions (30-40°F) than in dry cold. Most homeowners barely notice them.
Backup heat
During defrost, the heat pump briefly stops heating the house to clear frost off the outdoor unit. Backup heat keeps the air warm for those minutes and helps when demand outruns the heat pump. In a dual fuel system the gas furnace covers this. In a fully electric system we add heat strips in the air handler when the house needs them.

In a correctly sized system, backup runs only a small share of heating hours. Choosing gas or electric backup comes down to whether you have a gas line and what each costs to run.
Switchover temperature
In a dual fuel system, the switchover point is the outdoor temperature where the thermostat stops running the heat pump and runs the gas furnace instead. It is a setting, not the point where the heat pump stops working. Cold climate units keep heating down to -13°F and lower. We usually start it around 25°F and set it with you. At Xcel's October 2026 rates gas heat costs the same or less at every temperature, so raising the changeover keeps more of the heating on the cheaper fuel.

You set this on your thermostat. If gas prices rise, lower the switchover to use more heat pump. If electric rates spike, raise it to lean on gas sooner. That flexibility is one of dual fuel’s main advantages.
Energy density and operating costs
One therm of natural gas contains about 30x more energy than one kWh of electricity. A cold climate heat pump delivers 2.5 to 4 units of heat per unit of electricity, and that multiplier shrinks as temperatures drop. At Xcel's October 2026 all-in rates it isn't enough: 100,000 BTU costs about $0.92 from a 95% gas furnace and $1.23 from a heat pump at COP 3 on off-peak power, and the gap widens as it gets colder.
That is why dual fuel costs less to run than an all-electric system in a typical Denver winter. Solar panels and battery storage can close the gap; without them, dual fuel has the operating cost edge.
Operating Cost Comparison
Try Switchover Settings With Your Rates
Heat pump COP curves by outdoor temperature. Edit the rates to match your Xcel bill and toggle dual fuel mode.
Electric pricing mode
HP + gas backup
Have or planning solar?
BOVA-60MTB-M19E · 95% AFUE furnace · 2,000 sq ft · $0.88/therm · $0.155/kWh · Switch at 25°F
| Outdoor Temp | COP | Heat Pump | Gas (95%) | Winner |
|---|---|---|---|---|
55-65°F 609 hrs | 4.0 | $1.15 | $0.92 | Gas wins |
45-55°F 850 hrs | 4.0 | $1.15 | $0.92 | Gas wins |
35-45°F 1,369 hrs | 3.7 | $1.23 | $0.92 | Gas wins |
25-35°F 1,090 hrs | 3.3 | $1.38 | $0.92 | Gas wins |
15-25°F 636 hrs | 2.9 | $1.55 | $0.92 | Gas wins |
5-15°F 154 hrs | 2.5 | $1.82 | $0.92 | Gas wins |
-10-5°F 70 hrs | 2.0 | $2.27 | $0.92 | Gas wins |
Below -10°F 4 hrs | 1.6 | $2.88 | $0.92 | Gas wins |
At $0.88/therm gas and $0.155/kWh electric, heat pump is cheaper when COP exceeds 4.9.
Actual costs depend on insulation, thermostat settings, and installation quality.
Dual Fuel vs Fully Electric: Side-by-Side
| Dual Fuel | Fully Electric | Details | |
|---|---|---|---|
| Installed cost | $20,100 to $26,500 | $20,100 to $26,500 | |
| Annual heating cost (Denver) | $900 - $1,200 | $1,000 - $1,400 | |
| After rebates (typical) | $15,350 to $17,750 | $15,350 to $17,750 | |
| Best for | Homes with existing gas, cost-conscious | No gas line, solar + battery, electrification goals | |
| Xcel rebate eligibility | Up to $7,500 (HP portion) | Up to $7,500 | |
| Fuel flexibility | Switch between gas and electric anytime | Electricity only |
The math: Both options cost about the same to install and land in a similar out-of-pocket range after rebates. The real difference is operating cost: gas is cheaper per unit of heat than electricity at today's Xcel rates, so unless you have solar and batteries to offset it, dual fuel costs less to run than all-electric.
Which system fits your situation?
- Existing gas line? If yes, dual fuel is usually the smarter play. You already have the infrastructure. If no gas line, fully electric avoids the $2,100 to $5,300 cost of running one (though you may need an electrical panel upgrade to handle the added load). See our heat pump installation page for what’s included in either configuration.
- Furnace still in good shape? If your furnace has 10+ years of life left, dual fuel lets you use that asset as backup rather than scrapping it. But "still working" and "compatible with a new heat pump" are not the same thing: motor type, coil sizing, and control protocols all matter. If it’s been needing frequent repairs, that changes the math further.
- Solar + battery storage? If you generate your own electricity, fully electric makes the operating cost gap disappear. Without solar, dual fuel wins on monthly bills.
- Going all-electric on principle? Fully electric eliminates on-site combustion. If that matters to you, the slightly higher operating cost may be worth it.

2026 Rebates for Dual Fuel and Fully Electric Systems
Both configurations qualify for the same rebates. The incentive applies to the heat pump, not the backup system.
Example: A 3.5-ton Bosch IDS Ultra system at $23,300 installed nets out to about $15,550 after Xcel ($5,250), Power Ahead Colorado ($1,500) and the Colorado credit ($1,000). Same rebate whether you pair it with a furnace or an air handler.
Our Recommendation for Colorado Homeowners
After 12,000+ installations across Denver and the Front Range, here is our take:
Dual Fuel
Best for most Colorado homes with gas
- Lower operating costs in cold weather
- Uses your existing furnace as backup
- Switch between gas and electric anytime
- Proven reliability for Colorado winters
- Requires gas line and furnace maintenance
- Still burns gas below the changeover setting
Fully Electric
Best with solar, batteries, and air sealing, or no gas line
- No gas line or furnace needed
- Zero on-site combustion
- Great match for solar + battery homes
- One fuel source, simpler long-term
- Higher heating bills without solar
- Electricity costs more per BTU in extreme cold
For most Colorado homeowners with an existing gas line, dual fuel is the practical choice. You get the efficiency of a heat pump for the majority of the year and lower operating costs when temperatures drop. Fully electric is the right call if you have prepped the house for it (solar, battery storage, air sealing), have no gas line, or want to go all-electric on principle. Both work, both qualify for the same rebates. The wrong choice is keeping an aging furnace running without a heat pump when you could be cutting your heating and cooling costs by 30% or more.
Get a Free Estimate
Mitsubishi Diamond Elite dealer and Bosch contractor since 2014. We will walk you through both options, run the numbers for your home, and handle the rebate paperwork.




















