Furnace Installation in Twin Falls, ID
A new furnace here will run from September through May every year. Tell us about the house, and a licensed contractor who covers Twin Falls County will get in touch.
Tell us about the job
It takes about a minute.
Twin Falls asks a furnace to work nine months a year
From September through May, your furnace is what stands between you and a night that averages 21°F. That is nine months of the year it has to work, not just the coldest stretch of winter.
More than half the homes here heat with gas, and any new gas furnace installed now has to meet the federal minimum of 80 percent AFUE. That is the floor. What matters more is whether the unit going in is sized for your house and put in correctly, since it has nine months of real use ahead of it every year, not just a few weeks.
- 9 months
- September through May, your furnace is on duty
- 21°F
- the average winter night it heats against
- 54%
- 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 Twin Falls County compared with a gas furnace.
Estimates for a typical Twin Falls 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.
Idaho tests contractors through the HVAC Board before issuing this license, and the board keeps a record of who holds one. The license belongs to the contractor, not to any single job, so it tells you the person or company already met the state's standard before they get to your furnace.
A furnace installation in most cities and counties in Idaho also needs a permit from the local building office, with an inspection once the work is done. That covers the installation itself, separate from the contractor's license. In Twin Falls County, 53.7% of homes heat with gas, and it is gas furnace installations like this one where that inspection matters most, since a bad gas connection is the dangerous part of the job.
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 ceiling height, and how much window area you have facing north. A contractor sizes it with a load calculation, not a chart based on house size alone. Too big and it short-cycles, heating the room fast but never running long enough to warm the whole house evenly. Too small and it runs constantly all winter and still struggles to keep up on the coldest nights. Ask whoever quotes the job to walk you through the load calculation, not just tell you a number.
- How do I know it's time to replace my furnace?
- Age is the first thing to check. Furnaces installed new today are rated for at least 80 percent AFUE, so if yours is much older it's likely running well below that, burning more gas to make the same heat. Watch for other signs too. Rooms that used to heat evenly now have cold spots, the burner cycles on and off more than it used to, or you're calling for repairs most winters instead of every few years. Heat matters here from September through May, so a furnace on its way out doesn't leave you much of a break before you need it again.
- Is a high-efficiency furnace worth it?
- It depends on how long you plan to stay in the house and how much you run the furnace. With heat needed nine months a year here, and over half of Twin Falls County homes heating with gas, a furnace that turns more of that gas into heat instead of losing it up the flue adds up over a long heating season. High-efficiency furnaces vent through PVC pipe instead of a metal flue and condense moisture out of the exhaust, so a contractor needs to run a condensate line as part of the install. A contractor can walk you through the actual furnaces available for your house and let you weigh the difference yourself.