Furnace Installation in Grangeville, ID
A new furnace here will run from September through June every year. Tell us about the house, and a licensed contractor who covers Idaho County will get in touch.
Tell us about the job
It takes about a minute.
Grangeville asks a furnace to run ten months a year
Winter nights here average 18°F from December through February, and homes need the furnace running from September through June. That is ten months of the year the burner has to work, not just the coldest stretch of winter. A furnace going into that kind of run time needs to be sized and installed right the first time.
Grangeville has seen 66 winter storms and 23 damaging wind events over the last ten years. In Idaho, 11% of households went at least 24 hours without power in 2024, and 42% of homes here heat with electricity, so an outage can mean no heat as well as no lights. Any furnace installed today also has to meet the federal minimum of 80.0 percent AFUE, so the efficiency floor is already set. What matters most is getting the size and setup right for how long and how hard this furnace has to run.
- 10 months
- September through June, your furnace is on duty
- 18°F
- the average winter night it heats against
- 80% AFUE
- the federal minimum any new unit must meet
NOAA nClimDiv, 1991–2020 normals
Idaho requires HVAC contractors to hold a state license.
The state tests and records the contractor, not the job itself. That license stays attached to the business, so the same contractor can take on your furnace install and the next homeowner's after you, all under that one credential.
For an installation, the license tells you the contractor was tested and is on record with the state. The permit is separate. In most cities and counties in Idaho, swapping in a new furnace needs a permit from the local building office, and the work gets inspected once it's done.
Sources: Idaho Legislature · Idaho Division of Occupational and Professional Licenses
- What size furnace does my house need?
- The right size depends on your square footage, your insulation, your windows, and how your house is laid out, so there is no number that fits every home. A contractor works this out with a load calculation, not a chart based on square footage alone. Getting this right matters more here than in milder places, since your furnace needs to keep up on nights averaging 18°F. Too small and it will run constantly without catching up. Too large and it will short cycle, wearing out parts faster and leaving rooms uneven.
- How do I know it's time to replace my furnace?
- If your furnace is struggling to keep the house warm, needs repairs more than once a year, or is old enough that parts are hard to find, it is time to start looking at replacement. Rising bills with no other explanation are another sign, since a furnace losing efficiency has to run longer to do the same job. With heat needed here from September through June, a furnace that cannot keep up is a bigger problem than it would be somewhere with a short winter. A contractor can look at its age and condition and tell you whether repair still makes sense or whether you are past that point.
- Is a high-efficiency furnace worth it?
- It depends on how long you plan to stay in the house and what furnace you have now. Any non-weatherized gas furnace made since November 2015 already has to reach at least 80 percent AFUE, so the real question is whether it makes sense to go higher than that. Since homes here need heat for 10 months of the year, a furnace running that much of the year has more chances to make up ground on efficiency than one running only a few months. A contractor can walk you through the options and what each one means for your specific house.