Furnace Installation in Missoula, MT
A new furnace here will run from September through June every year. Tell us about the house, and a licensed contractor who covers Missoula County will get in touch.
Tell us about the job
It takes about a minute.
Missoula asks a furnace to run ten months a year
From September through June, your furnace is the thing standing between you and a 17°F night. That is not a season, that is most of the year, and the unit you install has to hold up to it winter after winter.
More than half of homes here heat with gas, and any new non-weatherized gas furnace has to reach at least 80 percent AFUE by federal rule. That is the floor, not a selling point. Power matters too. Montana saw 18% of households lose power for 24 hours or more in 2024, and the region has logged 164 winter storms and 69 damaging wind events over the past ten years. A furnace that depends on power to run is only as reliable as the grid on the night you need it most.
- 10 months
- September through June, your furnace is on duty
- 17°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 $90 a year to run in Missoula County compared with a gas furnace.
Estimates for a typical Missoula County home, from EIA household energy data, Montana fuel prices and NOAA climate normals. Your home will differ.
Montana requires HVAC contractors to hold a state license.
The state tests the contractor and keeps the license on file with the Department of Labor and Industry. That license belongs to the contractor, not to any one job. Montana also sets a line at $2,500. Work under that amount can be done without a licensed contractor. A furnace installation runs well past that line, so the person doing this job needs to hold the license.
In most cities and counties, a furnace replacement also needs a permit from the local building office and an inspection once the work is done. That inspection is what catches a bad gas connection or a venting mistake. More than half the homes in Missoula County heat with gas, so that check matters here.
Source: Montana Legislature
- What size furnace does my house need?
- A contractor works this out with a load calculation, not by matching the size of the furnace you have now. That calculation looks at your square footage, insulation, window count and layout, and around here it also has to account for winter lows that average 17°F. A furnace that is too big will short cycle and wear out faster. One that is too small will run constantly and still leave rooms cold. This is worth getting right rather than guessing, since your home needs heat most months of the year here.
- How do I know it's time to replace my furnace?
- Watch for a furnace that struggles to keep up on the coldest nights, cycles on and off more than it used to, or needs a repair call every season. Rising gas bills with no change in how you use the house are another sign the unit is losing efficiency. Age matters too. Furnaces installed before 2015 may not meet the 80 percent AFUE minimum that applies to gas furnaces made after November 19, 2015, so an older unit is working harder to make the same heat. With heat needed here from September through June, a furnace that is already struggling early in the season will only get worse as the nights get colder.
- Is a high-efficiency furnace worth it?
- It depends on how much you heat and what you're replacing. Homes here need a working furnace for 10 months of the year, and over half of Missoula County homes heat with gas, so the furnace runs a lot more here than it would somewhere with a short winter. A high-efficiency model burns less gas to produce the same heat, and that difference adds up over that many months of use. A contractor can walk through the actual models and their AFUE ratings for your house, since the right choice depends on your current setup and how the furnace is vented.