Furnace Installation in Mountain Home, ID
A new furnace here will run from September through June every year. Tell us about the house, and a licensed contractor who covers Elmore County will get in touch.
Tell us about the job
It takes about a minute.
Ten months of heating in Mountain Home
Winter nights here average 21°F from December through February, and homes need heat from September through June. That is ten months a year your furnace is expected to work, not just the coldest weeks of winter. A new furnace has to be sized and installed for that kind of run time, not for a mild season with a few cold snaps.
More than half of homes here heat with gas, and any non-weatherized gas furnace built since November 2015 has to reach at least 80 percent AFUE by federal rule. Power matters too. Idaho saw 11 percent of households lose power for 24 hours or more in 2024, and the county has logged 84 winter storms and 36 damaging wind events over the past ten years. A furnace installed here should be set up to start back up on its own once power returns.
- 10 months
- September through June, your furnace is on duty
- 21°F
- the average winter night it heats against
- 53%
- of homes here heat with gas, so most furnaces here burn gas
- 80% AFUE
- the federal minimum any new unit must meet
NOAA nClimDiv, 1991–2020 normals
A high-efficiency gas furnace would save about $70 a year to run in Elmore County compared with a gas furnace.
Estimates for a typical Elmore County home, from EIA household energy data, Idaho fuel prices and NOAA climate normals. Your home will differ.
Idaho requires HVAC contractors to hold a state license.
The license comes from the HVAC Board, and it covers the contractor, not this specific furnace installation. It means the state tested this contractor and keeps a record of who holds one.
For the installation itself, most cities and counties in Idaho also require a permit from the local building office, with an inspection once the work is done. That is separate from the license, and it is where the gas connection on your new furnace gets checked. In Elmore County, more than half of homes heat with gas, so that permit and inspection apply to a lot of jobs like this one.
Sources: Idaho Legislature · Idaho Division of Occupational and Professional Licenses
- What size furnace does my house need?
- It depends on your square footage, your insulation, your windows, and how the house is laid out. A furnace that's too big cycles on and off too often and never runs long enough to heat evenly. One that's too small runs constantly and still can't keep up on the coldest nights, and here that means nights near 21°F. A contractor works this out with a load calculation, not a rule of thumb based on square footage alone.
- How do I know it's time to replace my furnace?
- An aging furnace that needs repairs more than once a season is telling you something. Rising bills for no clear reason, rooms that won't hold an even temperature, and a burner flame that's yellow instead of blue are all signs the unit is struggling. With heat needed here from September through June, a furnace that's already worn down doesn't get much of a break to recover. A contractor can tell you whether what you're seeing is worth repairing or whether it's time for a new unit.
- Is a high-efficiency furnace worth it?
- It depends on how long you plan to stay in the house and what you're replacing. A high-efficiency furnace burns less gas to make the same heat, and that adds up over a heating season that runs 10 months here. Every new non-weatherized gas furnace sold now has to hit at least 80 percent AFUE by law, so the real choice is between that baseline and a higher-efficiency model. A contractor can lay out the difference in installed cost between the two for your specific house.