Which is Right For You?
If you are replacing your furnace and AC, a heat pump handles both jobs. The real question is what backs it up on the coldest nights: your existing gas furnace (dual fuel) or electric heat strips (fully electric). This guide covers the costs, operating differences, and rebates for each option in Colorado.
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 temperature drops below a set switchover point, the system automatically switches to gas.
Because natural gas has roughly 30x the energy density of electricity, gas heating costs less per BTU in the coldest weather. Dual fuel takes advantage of this: heat pump when it is efficient, furnace when gas is cheaper. You set the switchover temperature on your thermostat.
Dual Fuel Features
- Gas furnace backup below switchover temp
- 50%+ of heating hours electrified
- Switch between fuels automatically
- Typical heating range: 17°F and above
- 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. For homes with solar panels and battery storage, fully electric can offset most or all of the operating cost premium. Without solar, expect somewhat higher heating bills in winter compared to dual fuel.
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
Every heat pump installation in Colorado needs some form of backup heat. During defrost cycles, the heat pump temporarily stops heating your home. Without backup, you would feel the temperature drop. In a dual fuel system, the gas furnace covers this. In a fully electric system, heat strips in the air handler do the same job.
Backup heat runs only a small fraction of the year - typically a few dozen hours in a Denver winter. It is not a replacement for the heat pump; it is a bridge during defrost and extreme cold. The choice between gas backup and electric backup is really a question of operating cost and whether you have an existing gas line.
Switchover temperature
In a dual fuel system, the switchover point is the outdoor temperature where the system switches from heat pump to gas furnace. Standard heat pumps typically switch around 30°F. Cold climate units can stay efficient down to -13°F or lower, so the switchover drops to 15-20°F - meaning the heat pump handles the vast majority of heating hours.
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. Heat pumps are 2.5-4x more efficient than gas furnaces at converting energy to heat, but that multiplier shrinks as temperatures drop. The result: above ~25°F, cold climate heat pumps cost 15-20% less to run than a high-efficiency furnace. Below 25°F, gas pulls ahead by about 15%. Below 0°F, gas wins by ~20%.
For a fully electric system, that cold-weather premium adds up to roughly $100-$300/year more than dual fuel in a typical Denver winter. Solar panels and battery storage can eliminate that gap; without them, dual fuel has a real operating cost edge.
Operating Cost Comparison
Dual Fuel vs Heat Pump Operating Costs
Compare annual heating costs with real equipment data. Toggle dual fuel mode to see the optimal switchover temperature for your home.
Electric pricing mode
HP + gas backup
Have or planning solar?
BOVA-60MTB-M19E · 95% AFUE furnace · 2,000 sq ft · $1.10/therm · $0.140/kWh · Switch at 25°F
| Outdoor Temp | COP | Heat Pump | Gas (95%) | Winner |
|---|---|---|---|---|
55-65°F 578 hrs | 4.0 | $1.04 | $1.16 | HP wins |
45-55°F 808 hrs | 4.0 | $1.04 | $1.16 | HP wins |
35-45°F 1,310 hrs | 3.7 | $1.12 | $1.16 | HP wins |
36°F (crossover) Break-even point | 3.5 | $1.17 | $1.17 | Tie |
25-35°F 1,048 hrs | 3.3 | $1.25 | $1.16 | Gas wins |
15-25°F 613 hrs | 2.9 | $1.40 | $1.16 | Gas wins |
5-15°F 149 hrs | 2.5 | $1.65 | $1.16 | Gas wins |
-10-5°F 69 hrs | 2.0 | $2.05 | $1.16 | Gas wins |
Below -10°F 4 hrs | 1.6 | $2.60 | $1.16 | Gas wins |
At $1.10/therm gas and $0.140/kWh electric, heat pump is cheaper when COP exceeds 3.5.
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 | $19,000 - $25,000 | $19,000 - $25,000 | |
| Annual heating cost (Denver) | $900 - $1,200 | $1,000 - $1,400 | |
| After rebates (typical) | $12,000 - $14,000 | $12,000 - $14,000 | |
| Best for | Homes with existing gas, cost-conscious | No gas line, solar + battery, electrification goals | |
| Xcel rebate eligibility | Up to $10,250 (HP portion) | Up to $10,250 | |
| 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: dual fuel saves $100-$300/year on heating because gas is cheaper per BTU in cold weather. Unless you have solar + batteries to offset that, dual fuel costs less to run.
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 $2,000-$5,000 cost of running one.
- 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.
- 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 $22,000 installed could net out to around $13,000 after Xcel rebates ($7,875) and Colorado state credit ($1,500). 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 on coldest nights
Fully Electric
Best with solar + batteries 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 solar + battery storage, no gas line, or want to go all-electric. 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.
