- Dual-fuel hybrids almost always out-perform all-electric systems economically in the Chicago metro given current gas vs. electric rates.
- All-electric heat pumps make more sense where gas isn't available or where you have solar panels offsetting electricity costs.
- Dual-fuel systems require an existing gas furnace (or a new one) and gas service — not a fit for all-electric homes.
- Legendary flat-rates both options and can run a payback analysis for your specific home.
Dual-fuel is the right fit when
You have natural gas service, existing ductwork, and want to reduce cooling costs while keeping gas for deep-cold heating. The crossover point on the North Shore (typically around 25–35°F) means the heat pump handles fall, spring, and mild-winter days at high efficiency.
Heat-pump-only is the right fit when
Gas service is unavailable or being removed, you have rooftop solar reducing electricity cost, or you're targeting all-electric home heating. Requires a cold-climate inverter model rated ≥HSPF₂ 8.1 for Illinois winters.
Option A: Dual-fuel hybrid (heat pump + gas furnace backup)
The heat pump operates as primary heating and cooling. When outdoor temperatures fall below the programmed balance point (often 30–35°F), the gas furnace takes over automatically. This delivers heat-pump efficiency during the majority of the heating season while keeping gas for the coldest days. Installed cost $8,000–$14,000 for a complete system replacement. ComEd rebates may stack; Winnetka Electric customers should verify municipal utility rebate rules separately.
Option B: Cold-climate all-electric heat pump
Inverter-driven models (e.g., Daikin Fit) with ratings to –13°F can heat effectively through most Illinois winters. Electric resistance strips handle the extreme-cold margin. Operating costs depend heavily on electric rates — at typical ComEd TOU rates, operating costs may exceed dual-fuel in sub-20°F weather. Simplest mechanical system; no gas line required.
Incorrect balance-point setting on a dual-fuel system
If the balance point is set too high, the furnace runs when the heat pump would be more efficient — wasting gas. Legendary programs balance points based on local utility rates at commissioning.
Oversizing electric resistance on an all-electric system
Oversized aux heat strips run at high cost during cold snaps. A properly sized inverter-speed heat pump minimizes aux heat reliance.
Not accounting for utility rate structures
ComEd time-of-use rates can make all-electric systems more expensive than expected. Dual-fuel hybrids hedge against electric rate increases.
Questions homeowners ask
- How does the system know when to switch from heat pump to gas?
- The smart thermostat or hybrid controller monitors outdoor temperature and activates the gas furnace when temps drop below the programmed balance point (typically 25–35°F, set at installation).
- Do ComEd rebates apply to dual-fuel heat pumps?
- ComEd offers rebates on qualifying heat pump installations. Winnetka Electric customers should check with Winnetka's municipal utility directly, as ComEd rebate programs do not apply to Winnetka's service territory. Legendary confirms applicable rebates before purchase.
- What happens if the gas furnace in a dual-fuel system fails?
- The heat pump continues to operate as a backup heat source — you'll have heat, but at reduced capacity in very cold weather. Legendary recommends a service agreement to catch furnace issues before the heating season.
Editorial provenance
Content by Legendary Service editorial team
Updated:
Methodology
Guidance compares the stated system factors, applicable utility program rules, and the conditions that must be confirmed in the home. Figures are planning ranges, not quotes; Legendary Service provides an upfront flat-rate price after diagnosis.