Madison winters drop hard and stay cold, so a new furnace must be sized to the actual heat loss of the house rather than rule-of-thumb square footage. Older homes on the Isthmus and in Downtown often have balloon framing, undersized returns, and masonry chimneys that require stainless liners or power-vented units to meet current Dane County venting rules. We measure every run, check combustion air paths, and verify the existing duct system can handle the new static pressure before we set the unit.
Homes in Shorewood Hills, Maple Bluff, and Monona frequently sit on slabs or have finished basements that limit access for condensate drains and combustion air intakes. In these neighborhoods we often run new PVC intake and exhaust lines through rim joists rather than reuse old B-vent that no longer meets code clearance. Warm humid summers also mean the new system must integrate with existing AC coils without creating temperature swings that drive humidity back into living spaces.
Nearby cities like Middleton, Sun Prairie, and Verona have newer subdivisions with tighter envelopes and higher-efficiency equipment already in place. When we install in these areas we match the furnace to the existing ECM blower and two-stage thermostat so the system stages properly instead of short-cycling on shoulder days. Every job includes a final combustion analysis and static pressure test so the homeowner sees exactly how the new equipment performs under real Madison load conditions.
Technician insight
In Madison the thing that catches most people out with furnace installation is the condition of the return air paths in 1920s–1940s homes on the Isthmus and East Side. Those balloon-framed houses often have one undersized return that chokes a new high-efficiency unit and creates negative pressure that pulls combustion gases back into the living space.
Istmhus Bungalow Furnace Install
The 1938 bungalow had a failing gravity furnace and single 12-inch return. We ran a Manual J, added a second return through the dining room wall, installed a 96% furnace with new PVC vents, and completed combustion and static tests before the first real cold snap.
Furnace Installation Services We Offer
✓High-Efficiency Furnace Installation
Install 95%+ AFUE condensing furnaces with proper PVC venting sized for Madison's cold design temperatures and older chimney constraints.
✓Natural Gas Furnace Replacement
Remove old natural gas units and set new equipment while addressing common Dane County issues like undersized returns in East Side bungalows.
✓Ductwork Modifications for New Furnaces
Resize or add returns and supply runs so the new furnace delivers even heat in two-story homes on the West Side and in Fitchburg.
✓Slab Home Furnace Installation
Route condensate and combustion air lines through rim joists in Monona and Maple Bluff slab homes where basement access is limited.
✓Upflow Furnace Installation in Attics
Set upflow units in Shorewood Hills and Verona attics with correct platform construction and freeze protection for Dane County winters.
Furnace Installation Cost in Madison, WI
| Service | Typical Range | What Affects It |
|---|---|---|
| Standard 80% Furnace Installation | $3,200–$4,800 | Moves with duct modifications needed in older Isthmus and Downtown homes |
| High-Efficiency 95%+ Installation | $4,600–$7,200 | Includes new PVC venting and condensate handling typical for East Side and Monona |
| Ductwork Modifications | $800–$2,400 | Varies by how many returns must be added in two-story West Side homes |
| Attic or Slab Access Work | $600–$1,500 | Extra labor for Shorewood Hills attics and Maple Bluff slab homes |
Ranges are typical for Madison, WI and confirmed with an exact written quote before any work starts.
How it works
- 1
Load Calculation and Site Survey
We measure the home room-by-room and inspect existing ductwork, venting paths, and combustion air sources in the specific Madison neighborhood.
- 2
Equipment Selection and Quote
Match furnace efficiency and blower type to the house and provide an upfront quote that lists every required modification for the address.
- 3
Removal and Prep
Disconnect and remove the old unit, then modify returns, vents, and drains as needed before setting the new furnace on the prepared platform.
- 4
Startup and Testing
Perform combustion analysis, static pressure readings, and thermostat integration, then walk the homeowner through the final settings.
Pricing
Upfront quotes after we inspect the existing ductwork, venting, and access in your Madison home.