Furnace Installation in Ennis, MT
A new furnace here will run from August through June every year. Tell us about the house, and a licensed contractor who covers Madison County will get in touch.
Tell us about the job
It takes about a minute.
Ennis asks a furnace to run almost all year
Homes here need heat eleven months a year. Winter nights average 14°F from December through February, cold enough that the burner is cycling on and off for months at a stretch. That kind of run time is what a new furnace has to be built for.
Nearly half the homes in the area heat with propane, and a propane furnace has to be matched to that fuel from the start. Any new gas furnace installed today also has to meet the federal minimum of 80.0 percent AFUE. Power loss is a real risk too. In Montana, 18% of households went at least 24 hours without power in 2024, and the area has logged 74 winter storms and 83 damaging wind events over the past ten years. A furnace installed here needs to hold up through all of that.
- 11 months
- August through June, your furnace is on duty
- 14°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 propane furnace would save about $180 a year to run in Madison County compared with a propane furnace.
Estimates for a typical Madison 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 and licenses the contractor, not the job, so the license you're checking on the crew has already been vetted by the Department of Labor and Industry before they ever showed up. Montana does carve out an exception for small jobs, work under $2,500 doesn't need a licensed contractor, but a furnace installation runs well past that line, so this job falls under the license requirement.
For an installation, most cities and counties also require a permit from the local building office, with an inspection once the furnace is in. That inspection is separate from the license. The license tells you the contractor was tested and is on record with the state. The permit and inspection tell you this specific furnace, its venting and its gas connection were checked once the work was done.
Source: Montana Legislature
- What size furnace does my house need?
- The right size depends on your square footage, your insulation, your windows, and your ceiling height, so there is no number that fits every house. A contractor works this out with a load calculation, not a chart based on home size alone. This matters more here than in a mild climate. With winter nights averaging 14°F, a furnace that is even a little undersized will run constantly and still fall behind, and one that is oversized will cycle on and off and wear out early. Have a contractor measure your house rather than guess.
- How do I know it's time to replace my furnace?
- Watch for uneven heat between rooms, a furnace that runs longer than it used to, or repairs that keep coming back. Age matters too. Furnaces built after November 2015 have to reach at least 80 percent AFUE, so if yours is older than that, it may be burning more gas or propane than a new one would for the same heat. Since homes here need heat 11 months a year, a furnace that is struggling gets little rest to recover. If a contractor has told you the heat exchanger or blower motor is going, that is usually the point where repair stops making sense.
- Is a high-efficiency furnace worth it?
- A high-efficiency furnace burns less fuel to produce the same heat, and with heat needed here 11 months out of the year, that adds up over more months than it would somewhere milder. Nearly half of homes in this area heat with propane, and propane costs more per unit of heat than natural gas, so the fuel savings from a more efficient furnace are worth more here than in a gas-heated home. A contractor can walk through the options and price the job for your house.