Heat pump or gas furnace? Which is right for a Treasure Valley home

If you're replacing a heating system in Boise, Meridian or Nampa this year, you're going to hear the words heat pump a lot. Here's the honest comparison from a shop that installs both.

A gas furnace burns gas to make heat. It's simple, it's powerful on the coldest nights, and gas has been cheap in Idaho for a long time. A new two-stage furnace is quieter and more even than the single-stage unit it replaces.

A heat pump moves heat from outside air into the house. It doesn't make heat, it moves it, which is why it can deliver two or three units of heat for every unit of electricity. Cold-climate models hold full output to about 5 degrees and keep going below that.

On cost to run: through most of our winter, which is mild to cold rather than brutal, a cold-climate heat pump heats for less than gas at current rates. On the handful of near-zero nights, gas wins.

That's why the answer for a lot of valley homes is both. A dual-fuel system pairs a heat pump with a gas furnace. The heat pump carries the shoulder seasons and most winter days; the furnace takes over below a temperature we set. You get the efficiency without giving up the backup.

All-electric makes sense for homes without gas, for new builds, and for anyone chasing the largest rebates and tax credits, which go to heat pumps. It needs a cold-climate model sized for the valley's design temperature, not a national average.

What we'd do: if you have a good furnace under ten years old and the AC is due, replace the AC with a heat pump and go dual fuel. If both are due, price a heat pump system against a furnace-and-AC pair with the rebates counted, and pick the one whose monthly numbers you like. Either way, insist on a load calculation.