Furnace Installation in Flagstaff, AZ
A new furnace here will run from October through May every year. Tell us about the house, and a licensed contractor who covers Coconino County will get in touch.
Tell us about the job
It takes about a minute.
Flagstaff asks a furnace to work eight months a year
From October through May, your furnace is what keeps the house livable. Winter nights average 23°F here, cold enough that the burner is cycling on and off for most of the day and night. That kind of run time adds up over a season, and it adds up again the next one.
A new gas furnace installed here has to meet a federal minimum of 80 percent AFUE, and gas is what close to half the homes in the area heat with. Power is also worth planning around. About 7 percent of Arizona households went at least 24 hours without power in 2024, and Coconino County has logged 201 winter storms and 146 damaging wind events over the past ten years. A furnace that comes back on by itself when the power returns matters here.
- 8 months
- October through May, your furnace is on duty
- 23°F
- the average winter night it heats against
- 80% AFUE
- the federal minimum any new unit must meet
NOAA nClimDiv, 1991–2020 normals
A high-efficiency gas furnace would save about $130 a year to run in Coconino County compared with a gas furnace.
Estimates for a typical Coconino County home, from EIA household energy data, Arizona fuel prices and NOAA climate normals. Your home will differ.
Arizona requires HVAC contractors to hold a state license.
The Registrar of Contractors licenses the contractor, not the job itself. That means the state has tested the person or business taking on your furnace install and keeps a record of who they are, but the license itself does not cover what happens on this particular job.
That check comes from the county instead. In most cities and counties, a furnace install needs a permit from the local building office, with an inspection once the work is done, and that is what catches a bad gas connection or a vent run that was not put together right. Close to half the homes in Coconino County, 47.9 percent, heat with gas, which is exactly the kind of job that inspection is meant to cover.
Sources: Arizona State Legislature · Arizona Registrar of Contractors
- What size furnace does my house need?
- It depends on your square footage, your insulation, your windows, and your home's layout, so there's no number you can guess at safely. A contractor works this out with a load calculation, not a chart based on house size alone. Too big and the furnace short cycles, heating the air fast but never running long enough to feel even. Too small and it runs constantly and still can't keep up when it's 23°F outside. With heat needed here from October through May, getting this number right matters.
- How do I know it's time to replace my furnace?
- Age is one clue, and so is how often you're calling a contractor for the same repair. Watch for uneven heat between rooms, a furnace cycling on and off more than it used to, or a gas bill climbing without another explanation. If repairs keep piling up on an aging unit, that's usually the sign to stop repairing and start planning a replacement. Homes here need heat from October through May, so a furnace that's struggling has eight months a year to prove it.
- Is a high-efficiency furnace worth it?
- Any gas furnace built since November 2015 already has to reach at least 80 percent AFUE, so the real question is whether it's worth paying for something higher than that. With heat needed here from October through May, a furnace running that many months has more chances to earn back the difference in fuel use. A contractor can walk you through the specific models and what each one would mean for your house.