Every replacement we sell includes the furnace, the labor, the permit, and the commissioning. Here is what is in the standard scope, and what we quote separately if your house needs it.
A correctly sized gas or electric furnace matched to your home's load calculation, plus a new programmable or smart thermostat wired and configured. We register the manufacturer warranty in your name the day we commission the unit.
We pull the mechanical permit with your city or county, schedule the inspection, and meet the inspector on site. You get the signed-off card for your records, which matters when you sell the house and the buyer's agent asks for mechanical permits.
New flue pipe or PVC venting run to current code, with combustion air sized to ANSI/ASHRAE Standards. On condensing units we slope the PVC correctly and install a condensate trap and drain line that will not freeze in an Idaho winter.
We disconnect and reconnect the gas line with a new sediment trap and shutoff, and wire the electrical feed, transformer, and control board. Every connection gets leak-tested with a manifold gauge set before we leave the driveway.
Gas pressure set, temperature rise verified, combustion checked with a flue gas analyzer, and airflow confirmed with an anemometer. Then we walk you through the thermostat, the filter size, and where the shutoffs are, and leave the paperwork on the kitchen counter.
Furnace Replacement in Idaho is the full removal and re-installation of your home's primary heat source, including the new unit, the flue or venting, the gas line or electrical feed, the thermostat wiring, and the permit inspection. It is not a swap-and-go job. We pull the old cabinet, check the plenum and duct connections, verify the heat exchanger on the outgoing unit, and confirm the new furnace matches your home's actual heat load rather than the guess a builder made decades ago.
Idaho homes take a beating. A furnace in Ashton runs through minus-20 nights, while a unit in Lewiston deals with river-valley humidity and milder but longer shoulder seasons. That spread matters. If you are searching for affordable Furnace Replacement in Idaho, the cheapest quote often skips the manual J load calculation, the duct static pressure test, or the combustion analyzer tune that keeps a new unit under warranty. We do all three on every job.
Five steps, start to finish. Most single-family replacements are done in one day, with larger or dual-system homes running into a second morning.
Schedule
Call or book online — a real human picks up and confirms a 2-hour arrival window.
Diagnose
Licensed tech inspects on-site, then walks you through the cause and your options.
Fix
The job is completed to code and done right the first time — no shortcuts, no surprises.
Guarantee
Every job backed by a written workmanship warranty — and we stand behind it.
Manifold gauge set
Used to set inlet and manifold gas pressure to the manufacturer's spec on every new furnace. Wrong gas pressure causes sooting, short cycling, and premature heat exchanger failure.
Combustion analyzer / flue gas analyzer
Measures carbon monoxide, oxygen, and stack temperature at the flue. We use it to confirm the new unit is burning clean and to document the reading on your commissioning sheet.
Anemometer
Reads airflow at the registers so we can confirm the new blower is moving the CFM the load calculation calls for. Low airflow is the number one cause of comfort complaints after a replacement.
Clamp meter and multimeter
Used to check amp draw on the blower motor, verify the transformer and control board voltages, and test the igniter and limit switch during commissioning and any follow-up service.
Vacuum pump and tube brush
For gas line purging and for cleaning burners and the blower wheel during the install. A clean burner assembly is what keeps a new furnace running at its rated AFUE.
Fin comb
Straightens bent fins on the evaporator coil and any exposed duct fins we find during removal, so airflow is not restricted by damage from the old install.
ACCA manual J load calculation
We measure square footage, window area, insulation values, and ceiling height, then calculate the actual heating load for your house. Sizing to the load instead of matching the old unit is what stops short cycling and keeps the new furnace in warranty.
Static pressure and duct evaluation
Before we set the new cabinet we measure total external static pressure on the existing ductwork. If the return air is undersized, we tell you and quote the fix, because a new furnace on a choked duct system will never deliver the comfort you paid for.
Combustion analysis and temperature rise verification
After startup we check flue gas with a combustion analyzer and measure temperature rise across the heat exchanger against the manufacturer's rating plate. Both numbers go on your commissioning sheet so you have a baseline for future tune-ups.
Code-correct venting and permit inspection
Every install follows ANSI/ASHRAE Standards for venting and combustion air, plus the local jurisdiction's amendments. We pull the mechanical permit and meet the inspector, so the job is documented and code-correct at resale.
01
What we do: We treat it as an emergency, roll a truck the same day, and if the unit is beyond repair we pull a shelf-stock furnace in a common size and install it that day or the next morning.
→ Heat back on within 24 to 48 hours, with the permit filed and the inspection scheduled before the week is out.
02
What we do: We quote the replacement, pull the permit, and complete the install on a schedule that fits the closing timeline. We provide the inspection sign-off and warranty paperwork for the file.
→ The sale closes on time with a documented, code-correct furnace replacement instead of a price concession.
03
What we do: We run a load calculation, confirm the existing venting can be replaced with PVC, and install a 96 percent AFUE unit with a variable-speed blower and a smart thermostat.
→ Winter gas usage drops 20 to 35 percent, and the house holds temperature more evenly room to room.
04
What we do: We schedule the install in the vacancy window, pull the permit, and coordinate the inspection so the unit is signed off before the next lease starts.
→ A code-compliant furnace, a registered warranty, and no disruption to the rental income.
Idaho is not one climate. A furnace in Driggs or Ashton faces Teton Valley winters that drop past minus 20, which means we spec condensing units with freeze protection on the condensate line and confirm the venting slope so ice does not block the pipe. In the Treasure Valley, Star and Middleton homes deal with milder temperatures but a lot of new construction, where builder-grade furnaces are often oversized for the actual square footage. In the Panhandle, Rathdrum and Coeur d'Alene see long, wet shoulder seasons that push a furnace to run more hours per year than the same unit would in Boise. Altitude matters too: most Idaho towns sit between 2,500 and 6,000 feet, and a furnace set up for sea level will run rich and soot the heat exchanger. We derate gas pressure and re-check combustion at your elevation on every install. If you are looking for a furnace install Idaho crew that understands the difference between a Snake River Plain winter and a Teton Valley one, that is the work we do every week.
Idaho Falls
Older homes near the river have undersized return air ducts from mid-century builds. We frequently rebuild the return plenum during replacement to get proper airflow to the new furnace.
Star and Middleton
Fast new construction means builder-grade furnaces that are often oversized. We run a manual J load calculation before quoting, because the right size is usually one step smaller than what is in the closet.
Rathdrum and the Panhandle
Long, wet winters mean more run hours and more condensate. We spec freeze protection on condensing furnace drain lines and check the PVC vent slope carefully.
Lewiston
River-valley humidity and milder winters change the load profile. We size for the shoulder seasons so the furnace is not short cycling in October and April.
Sub-zero winter nights in Teton and Caribou counties
Condensate lines freeze and block, shutting down a condensing furnace. We install heat tape and slope the drain correctly so the unit keeps running through a minus-20 stretch.
High altitude across most of the state
Furnaces run rich at altitude unless gas pressure is derated and combustion is re-verified. We adjust at install and document the flue gas readings on your commissioning sheet.
Rapid new construction in the Treasure Valley
Builder-grade furnaces are often sized by square footage alone, not by load. We run a manual J calculation and frequently install a smaller, more efficient unit than the one we removed.
Older housing stock in rural Idaho towns
Original ductwork from the 1950s and 1960s is often undersized for a modern furnace. We measure static pressure and quote duct corrections when the return air cannot support the new unit.
Some furnace failures are worth repairing. Others mean the unit is on borrowed time and every dollar you spend on it is gone. Here is how we sort the two, and what replacement solves.
Problem
A cracked heat exchanger can push carbon monoxide into your living space. It is the one furnace failure you cannot ignore, and it cannot be repaired, only replaced.
Our Fix
We confirm the crack with a combustion analyzer and a visual inspection of the exchanger, then shut the unit down and quote a replacement. Most swaps happen within 24 to 48 hours of the diagnosis because we treat it as a safety call.
Problem
Short cycling wears out the blower motor, the igniter, and the limit switch, and it leaves the house cold while burning gas. It usually means the furnace is oversized or the heat exchanger is restricted.
Our Fix
We check static pressure, verify the unit is sized right, and inspect the exchanger. If the furnace is oversized or the exchanger is failing, replacement is the fix. We size the new unit with a manual J load calculation so it runs long, steady cycles.
Problem
A new blower motor one winter, a control board the next, then an inducer motor. Once a furnace passes 15 years old, the repair math stops working in your favor.
Our Fix
We show you the running total and the age of the unit, then quote replacement against another repair. Most homeowners break even on a new furnace in 4 to 6 heating seasons through lower gas bills and no repair calls.
Problem
Cold air from the vents in January usually means a failed igniter, a dirty flame sensor, or a gas valve that will not open. On an old furnace, it often signals the beginning of the end.
Our Fix
We diagnose the ignition sequence in order, igniter, flame sensor, gas valve, control board, and give you the repair price next to the replacement price. You decide. If it is a $200 part on a 10-year-old furnace, we will tell you to repair it.
A furnace that needs a new heat exchanger, a second blower motor, or a control board every other season is telling you something. Here is what a proper replacement buys you.
Lower monthly gas bills
A 2026 high-efficiency condensing furnace runs 95 to 98 percent AFUE. If your old unit is a 70 percent atmospheric model, you are paying for heat that goes up the flue. Most Idaho homeowners see a 20 to 35 percent drop in winter gas usage after a high efficiency Furnace Replacement Idaho install.
Heat that actually reaches rooms
We measure static pressure and check the return air path before we set the new cabinet. A correctly sized furnace paired with a clean blower and a fresh air filter pushes warm air to the far bedrooms instead of cooking the hallway thermostat and leaving the back of the house cold.
No more 2 a.m. no-heat calls
Cracked heat exchangers, failing inducer motors, and dirty flame sensors are the three most common reasons a furnace quits on the coldest night of the year. Replacing the unit removes all three failure points at once, and we pressure-test the gas valve and flue before we leave.
Warranty and code coverage
New Carrier, Trane, Lennox, and Rheem units carry 10-year parts warranties when installed by a licensed contractor with a pulled permit. A self-installed furnace voids that coverage and can fail an Idaho HVAC Contractor License inspection at resale. We pull the permit and register the warranty for you.
Typical 2026 pricing for a standard single-family furnace replacement in Idaho runs $3,200 to $7,800 installed, including the permit and commissioning. High-efficiency condensing units, dual-system homes, and jobs that need duct or plenum work land above that range. We quote the whole job in writing before we order equipment, and we tell you what drives the number so you can decide where to spend. If you want an affordable Furnace Replacement in Idaho without cutting corners on sizing or permits, this is how we price it.
Typical Investment Range
$3,200 - $7,800 installed, depending on size, efficiency, venting, and ductwork
The quote you sign is the price you pay. It covers the furnace, the permit, the labor, the thermostat, the commissioning, and the warranty registration. No diagnostic fee on replacement jobs, and no surprise add-ons after the old unit is on the truck.
What changes the price
Furnace size and AFUE
A larger BTU output and a higher AFUE rating both raise the equipment cost. A 96 percent condensing unit costs more up front than an 80 percent model but usually pays the difference back in 4 to 6 Idaho winters through lower gas bills.
Venting changes
If your old furnace used a metal flue and the new one is condensing, we run new PVC venting, which adds material and labor. If the existing venting can be reused and meets code, that cost comes off the quote.
Duct and plenum work
A new furnace on undersized ductwork will never deliver the comfort you paid for. If static pressure readings show the return air is too small, we quote a plenum rebuild or duct correction as a separate line item so you can see exactly what it costs.
Permit and inspection fees
Mechanical permit fees vary by city and county across Idaho and are passed through at cost. We pull the permit for you and meet the inspector, so there is no homeowner paperwork and no re-inspection surprise at resale.
Thermostat and controls
A basic programmable thermostat is included. Smart thermostats, zoning controls, and humidifier integration are add-ons we quote separately. Most homeowners upgrade to a smart thermostat for the scheduling and remote monitoring.
Access and removal
A furnace in a tight closet, attic, or crawlspace takes longer to remove and install than one in an open basement. We look at access during the quote visit and build the labor into the number up front.
Google ★★★★★4.9
Quoted a replacement on Tuesday, installed on Thursday, inspection signed off Friday. They ran a load calculation the other two companies did not bother with. New furnace is quieter and the house heats evenly for the first time. Worth every dollar.
BBB ★★★★★4.8
Our furnace died on a Sunday in a cold snap. They answered the phone, had a tech out that afternoon, and installed a new unit Monday morning. Clean work, permit pulled, and they cleaned up the basement better than they found it.
Yelp ★★★★★4.9
Straight answers on the phone and no pressure to buy the biggest unit. They showed me the cracked heat exchanger on the old furnace and explained the three options. We went with a 96 percent Rheem and our gas bill dropped about 30 percent.
We cover the whole state, from the Panhandle to the Snake River Plain to the southeast corner. That means a furnace install Idaho homeowners can schedule without waiting on a crew from three counties away. Here are some of the communities we serve most often, with the same written quotes, pulled permits, and same-day emergency availability everywhere we go.
Teton Valley winters hit minus 20 here, so we spec condensing furnaces with freeze-protected condensate lines and verify combustion at Ashton's elevation before we leave.
Buhl's mix of older farmhouses and newer builds means we run a manual J load calculation on every quote, because the right size is often smaller than what is in the closet.
High-altitude Driggs installs get gas pressure derated and combustion re-verified. We also check PVC vent slope carefully so ice does not block a condensing furnace in January.
Gooding homes on the Snake River Plain see wide temperature swings. We size for the cold end and set the thermostat schedule so the furnace is not short cycling in the shoulder seasons.
Many Idaho Falls homes have undersized return air from mid-century ductwork. We measure static pressure and rebuild the plenum when the old ducts cannot support a modern furnace.
Lewiston's river-valley humidity and milder winters change the load profile. We size for the shoulder seasons and check the condensate drain on every condensing install.
Fast new construction in Middleton means builder-grade furnaces that are often oversized. We run a load calculation and frequently install a smaller, more efficient unit than the one we removed.
Newdale's rural housing stock often has original 1960s ductwork. We measure static pressure and quote duct corrections when the return air cannot support the new furnace.
Long, wet Panhandle winters push furnaces to run more hours per year. We spec freeze protection on condensate lines and clean the blower wheel during every Rathdrum install.
Star's rapid growth means a lot of first-time replacements on 10 to 15-year-old builder units. We pull the permit, install a correctly sized furnace, and register the warranty the same day.
Victor sits at the cold end of Teton Valley, so we install high-efficiency condensing furnaces with heat tape on the drain line and verify temperature rise before we hand over the keys.
Real answers to the questions we hear most often from local homeowners and property managers.
Not every unit needs replacing. We diagnose igniters, flame sensors, gas valves, and blower motors first, and we tell you straight when a repair beats a new furnace. Many Idaho homeowners save thousands by fixing a $300 part instead of swapping the whole cabinet.
View Furnace RepairNo heat at 2 a.m. in a Rathdrum cold snap is an emergency. We run 24/7 emergency calls for no-heat, gas smell, and carbon monoxide alarms, and if the unit is beyond saving we can often roll straight into a replacement the same day.
View Emergency Furnace RepairNew construction, additions, and shop buildings need a furnace installed from scratch. We size the unit with a manual J load calculation, run the gas line and venting to code, and commission it with a combustion analyzer before we hand over the keys.
View Furnace InstallationA yearly tune-up keeps a new furnace under warranty and catches small problems before they strand you in January. We clean the flame sensor, check the thermocouple, test the limit switch, and verify temperature rise, usually in under 90 minutes.
View Furnace Tune-UpOngoing maintenance extends the life of any furnace by years. Our maintenance plan covers filter changes, blower cleaning, inducer motor inspection, and a full combustion check each fall, so your system is ready before the first hard freeze hits.
View Furnace MaintenanceDust, pet hair, and dryer lint choke a blower wheel and cut airflow. We pull the blower, brush the wheel, vacuum the cabinet, and clean the burners. A dirty furnace runs hot, short cycles, and wears out the heat exchanger faster than it should.
View Furnace CleaningCall us at (833) 588-3865 any time, day or night. We answer live, confirm your address, and send the closest truck. Most metro calls get a tech within hours, and you'll get a flat price before any work begins. Prefer email? Reach us at info@furnaceprosidaho.com and we'll respond the same day.
Phone
(833) 588-3865Address
Idaho
Hours
Mon–Fri: 7AM – 7PM
Sat: 8AM – 4PM
Sun: Emergency Only
24/7 Emergency Available
