The older guide on this site, heat pump versus gas furnace, is the two-machine choice. Dual fuel is the combination: a heat pump does the heating on milder hours, and the gas furnace takes over when the outdoor temperature drops to the thermostat’s changeover. A heat pump with no furnace still heats on those colder hours. It does it with electric resistance strips, the same heat people see when they select Emergency Heat.
Neither setup is automatically cheaper. This page does not claim a percent saved. A foothills house, Green Valley, Oro Valley, or SaddleBrooke can see colder mornings than a central Tucson house that is empty all day. The furnace, or the strips, is what you notice on those mornings. The heat pump is what you notice the rest of the season, including cooling in June.
Keeping the furnace means the gas line, the flue, and the furnace cabinet stay. Removing it is the conversion page. TEP’s heat-pump rebate, up to $720 when the job qualifies, is described on heat pump cost. It is not a reason by itself to remove a furnace that is still sound.
What each setup does
No price column. The difference is which machine runs, not a promised bill.
| Setup | On a mild Tucson morning | When the morning is actually cold |
|---|---|---|
| Heat pump only | The outdoor unit heats. Supply air is warm, not furnace-hot. | Electric strips, often labeled auxiliary or emergency, carry the house if the heat pump cannot. |
| Dual fuel | The heat pump heats. The furnace stays off. | The thermostat calls for the gas furnace. The outdoor unit is not the heat source then. |
| Gas furnace and a straight air conditioner | The furnace heats. There is no outdoor unit running for heat. | The furnace heats. There are no electric strips unless someone added them. |
Name, mobile phone, and ZIP are required. Street address can wait. We follow up the same business day by phone or email. That is a callback, not a promise of a repair the same day.