Furnace Repair in Miles City, MT
Furnaces here run from September through May. If yours quits, tell us what it's doing and a licensed contractor who covers Custer County will get in touch.
Tell us about the job
It takes about a minute.
Nine months of heat puts a lot of hours on your furnace
From September through May your furnace is the thing standing between your house and nights that average 11°F. That is nine months of the burner lighting and shutting off, over and over, and every one of those cycles wears on the igniter and the flame sensor. When one of those parts finally gives out, the burner won't light at all, and you notice fast at that temperature.
Custer County has had 17 winter storms and 94 damaging wind events over the past ten years. Wind like that can knock out power to the blower, and in Montana, 18% of households went at least a full day without power in 2024. Most furnaces start back up on their own once power returns, but a unit with a standing pilot needs someone to relight it by hand.
- 9 months
- September through May, your furnace is on duty
- 11°F
- the average winter night it heats against
- 62%
- of homes here heat with gas, so most furnaces here burn gas
- 17 winter storms
- in ten years, the nights a failure hurts most
NOAA nClimDiv, 1991–2020 normals
A new furnace would cut about $80 a year off heating for a typical Custer County home.
Estimates for a typical Custer County home, compared with an older unit built to the previous federal minimum, from EIA household energy data, Montana fuel prices and NOAA climate normals. Your home will differ.
Repair makes sense when one part has failed and the heat exchanger is sound.
Replacement makes sense when the heat exchanger is cracked or the furnace keeps needing parts.
Montana requires HVAC contractors to hold a state license.
The license is held by the contractor, not tied to the specific repair. It covers this job and every other job that contractor takes on, because the state tested and keeps a record of the contractor, not the work itself. Montana sets one exception. Work under $2,500 does not require a licensed contractor.
A furnace repair can land on either side of that line depending on the parts and labor involved. In Custer County, 61.9% of homes heat with gas, and gas is the part of this job where a bad connection matters most. Above $2,500, the license requirement applies, and the contractor doing the work is the one who has to hold it.
Source: Montana Legislature
- Why won't my furnace turn on?
- Most often the thermostat isn't calling for heat the way it should, or power isn't reaching the furnace. Check that the thermostat is set above room temperature and has fresh batteries if it uses them. Next check the furnace switch, which looks like a light switch near the unit, and the breaker for it. If those are fine, the igniter or flame sensor may have failed, and that's a job for a licensed contractor to diagnose.
- Why is my furnace blowing cold air?
- If air is moving but it's not warm, the burners likely aren't lighting even though the blower is running. A dirty flame sensor is a common cause. It sits near the burners and its job is to confirm the flame is lit, and once it's coated with residue it can shut the gas off before the air has a chance to heat up. This is worth getting looked at soon, since a furnace here runs from September through May and a house can lose heat fast at 11 below.
- Why won't my furnace pilot light stay lit?
- A pilot that won't stay lit usually means the thermocouple has worn out. That's the small part that sits in the pilot flame and tells the gas valve the flame is present. When it fails, the valve shuts the gas off as a safety measure even though you can relight the pilot. Wind can also blow out a pilot if the vent or flue draws air unevenly during a storm. Either way, a licensed contractor can replace the thermocouple or check the venting.