Furnace Installation in Madison, WI
A new furnace here will run from October through May every year. Tell us about the house, and a licensed contractor who covers Dane County will get in touch.
Tell us about the job
It takes about a minute.
Eight months of heat, on nights near 14 degrees
Madison asks a furnace to run from October through May. On winter nights averaging 14°F, it isn't cycling on and off for comfort. It's holding the house against real cold, most months of the year.
Most homes here heat with gas, and any new gas furnace installed now has to meet the federal minimum of 80.0 percent AFUE. Dane County has also logged 22 winter storms and 128 damaging wind events over the past ten years, and in 2024, 18% of Wisconsin households lost power for a day or more. A furnace that comes back on by itself when the power returns matters here, since the cold doesn't wait for the lights to come back on.
- 8 months
- October through May, your furnace is on duty
- 14°F
- the average winter night it heats against
- 68%
- of homes here heat with gas, so most furnaces here burn gas
- 80% AFUE
- the federal minimum any new unit must meet
NOAA nClimDiv, 1991–2020 normals
A high-efficiency gas furnace would save about $100 a year to run in Dane County compared with a gas furnace.
Estimates for a typical Dane County home, from EIA household energy data, Wisconsin fuel prices and NOAA climate normals. Your home will differ.
Wisconsin requires contractors to register with the state.
That registration puts the business on file with the state, so there's a record of who they are, but nobody tested their gas or furnace work to get it. Wisconsin also blocks counties and cities from layering on their own HVAC license, so registration is the only state-level record for a contractor doing this job anywhere in Dane County.
What actually checks the work on a furnace install is the local permit and inspection. Most cities and counties require a permit for a furnace replacement and an inspection once it's done, and that inspection is what catches a bad gas connection, which is the part of this job that can hurt someone. Most homes in Dane County heat with gas, so that inspection is doing real work here, not a formality.
Sources: Wisconsin Legislative Reference Bureau · Wisconsin Department of Safety and Professional Services
- What size furnace does my house need?
- That depends on your square footage, ceiling height, insulation, and how many windows you have, so there's no number to give without looking at the house. A contractor will do a load calculation, room by room, to size it correctly. Getting this wrong matters here. Too small and it can't keep up on a 14°F night. Too big and it'll short cycle, wearing out parts faster and leaving rooms uneven.
- How do I know it's time to replace my furnace?
- Age is the first thing to check, along with how often it's needed repair lately. If yours is cycling on and off more than it used to, running longer to heat the same rooms, or you've had a couple of repair calls in the last year or two, that's usually the sign. With heat needed here from October through May, a furnace that's struggling is a real risk, not just an inconvenience. A contractor can tell you whether it's worth repairing again or time to replace it.
- Is a high-efficiency furnace worth it?
- It depends on what you have now and how long you plan to stay in the house. Furnaces made since November 2015 are required to hit at least 80 percent AFUE, so if yours is older than that, a new one is a step up no matter which model you choose. High-efficiency units go further still, which matters more in a place where the furnace runs for 8 months of the year. A contractor can walk you through the options for your house and what each one means for your setup.