Short answerTypical market pricing in Washtenaw and western Wayne County puts an installed 80% AFUE gas furnace at roughly $4,000 to $7,000 and a 96% condensing furnace at roughly $5,500 to $10,000 in 2026. The spread comes from single-stage versus two-stage or modulating burners, blower type, PVC venting on condensing units, duct and electrical changes, and permits.
The honest range
Across Washtenaw and western Wayne County, typical market pricing for a replacement gas furnace installed in an existing home in 2026 looks like this:
- 80% AFUE single-stage: roughly $4,000 to $7,000 installed.
- 96% AFUE condensing, single or two-stage: roughly $5,500 to $10,000 installed.
- Modulating, variable-speed 97-98% units with communicating controls can run above that.
Those are market figures across many contractors, not Temprasure's price list. Our own quotes come from a free in-home estimate, because the house decides at least half of the number. Here is what moves it.
Equipment: AFUE, stages, and the blower
AFUE is the share of the gas that becomes heat in the house. An 80% furnace vents 20 percent of what you pay DTE for up a metal flue. A 96% unit squeezes most of that out through a second heat exchanger and vents the cooled exhaust through PVC. With 6,000-plus heating degree days here, the gas savings on the 96% unit are real; furnace efficiency 80 vs 96 AFUE runs the arithmetic.
Stages are how finely the furnace can turn down. Single-stage is on or off at full fire. Two-stage runs at about 65 percent most of the time and steps up on cold days, which means longer, quieter cycles and more even rooms in a two-story. Modulating units adjust in small increments. Each step adds to the equipment cost.
Blower type matters more than people expect. A PSC blower is cheap and uses a lot of electricity. An ECM blower uses a fraction of the power, which shows up on the DTE bill every month the fan runs, and it is standard on most mid-tier and up furnaces now. Single-stage vs two-stage vs variable-speed explains the trade-offs.
Size is a smaller cost factor than efficiency. An 80,000 BTU furnace and a 100,000 BTU furnace of the same model line are not far apart in price, but the right size matters enormously for comfort and equipment life, so we do a load calculation rather than copying the number off the old unit. What size furnace do I need covers why the old furnace is usually oversized.
Venting: the big difference between 80% and 96%
An 80% furnace vents hot exhaust through a metal pipe into a chimney, usually sharing it with the water heater. Replacing one 80% with another 80% keeps the existing flue, provided the chimney liner is sound.
A 96% furnace vents cool exhaust through PVC, out the side of the house, and takes its combustion air from outside through a second PVC pipe. That means drilling through the rim joist, running pipe, and a termination that meets clearance rules from windows, doors, the gas meter and the dryer vent. In a Michigan basement with a stone foundation, or a house where the furnace sits in the middle of the basement far from an exterior wall, the vent run is longer and the labor goes up.
The sneaky cost is the water heater. When the furnace leaves the chimney, an atmospheric water heater is left venting alone into a flue sized for both appliances. On a cold day that oversized flue can fail to draft, spilling exhaust into the basement. The fixes are a chimney liner sized for the water heater, or a power-vent water heater. We flag this on every 80-to-96 conversion estimate because a lot of homeowners have been surprised by it after the fact.
Ductwork, electrical and the rest of the job
- Transitions. A new furnace is rarely the same dimensions as the old one, so the supply plenum and return drop get new sheet metal.
- Duct corrections. An undersized return, a crushed flex run, or a 1950s ranch with one return grille for the whole house. We can replace the furnace without fixing those, but the furnace will not perform, and sometimes a return addition is the best money in the quote. Ductwork leaks in older Michigan homes covers what we find.
- Condensate handling on a 96% unit: a trap, a drain line to a floor drain, or a condensate pump when there is no drain nearby.
- Electrical. A dedicated circuit and a service switch are required. Older homes in Ypsilanti and Wayne with the furnace on a shared lighting circuit need a new run from the panel.
- Gas piping. A new drip leg, shutoff and flex connector are standard. A furnace that moves location may need pipe extended.
- Thermostat. Two-stage and modulating furnaces need a compatible thermostat. Often included; sometimes an upgrade.
- Filter cabinet. A 4-inch media cabinet is a common add-on at install time, because that is when the return drop is already being rebuilt.
- Permit and inspection. Washtenaw County and the Wayne County municipalities require a mechanical permit for furnace replacement. The cost is modest and it is included in a legitimate quote. HVAC permits in Ypsilanti and Washtenaw County explains why skipping it is a bad idea.
- Disposal of the old furnace.
Where the quotes cluster locally
A 1960s ranch in Westland or Garden City with an open basement, an existing chimney and a straightforward swap tends to land toward the lower-middle of the 80% range or the lower part of the 96% range. A two-story 2000s colonial in Canton or Saline that already has PVC venting and a return cabinet usually sits in the middle of the 96% range for a two-stage unit. The expensive quotes come from prewar houses in Ann Arbor and Ypsilanti where the furnace is in a Michigan basement 30 feet from an exterior wall, the ductwork is a 1950s retrofit, and the water heater needs a liner once the furnace leaves the chimney.
Rebates and credits that reduce the number
DTE Energy offers rebates on qualifying high-efficiency furnaces, and the federal 25C tax credit covers a share of a qualifying unit up to an annual cap. Both change year to year, and the program rules decide what qualifies, so the current details are in Michigan HVAC rebates and tax credits and DTE Energy rebates. A 96% two-stage furnace with an ECM blower is the typical qualifying configuration.
How we quote a furnace
Our estimates on replacements are free and come after we have seen the house: measured the ductwork, checked the chimney, looked at the vent path and the electrical, and run a load calculation. The number you get is flat-rate and includes the permit, and it does not change when the job turns out to be harder than expected. We also tell people when they do not need a new furnace. A 15-year-old 80% unit with a bad inducer is a repair, not a replacement, and we have sent more than a few homeowners back to furnace repair cost in Ypsilanti rather than sell them a furnace. When the time is right, our furnace installation page covers how the day goes.