Two numbers, one sheet of paper
Here is how a furnace replacement starts with us: with a repair quote. Even when a homeowner calls and says “I know it’s time, just tell me what a new one costs,” we still look at the old furnace and write down what fixing it would cost. Then we write down what replacing it would cost. Both numbers go on the same sheet. You read them at your kitchen table and decide.
That sounds slow. It isn’t. It adds maybe fifteen minutes to the visit, and it’s the only honest way to answer the question you actually have, which is not “what does a furnace cost” but “should I spend this money at all.”
Our techs aren’t paid on commission. Nobody at Porchlight makes more on a replacement than on a repair. That’s on purpose, and it’s the reason we can tell you, with a straight face, to keep the furnace you’ve got when it makes sense.
When the math actually says replace
Age alone doesn’t make the call. We’ve kept 22-year-old furnaces running safely, and we’ve told people with 11-year-old units that the repair wasn’t worth it. What moves us toward recommending a new furnace is one of these:
- A cracked or rusted-through heat exchanger. That’s the wall between the flame and the air you breathe. When it fails, combustion gases can reach the living space. We’ll show you the crack or the test result, not just tell you about it.
- A repair that costs more than the furnace has left in it. A big repair on a furnace near the end of its life often buys one winter. We’ll say that plainly.
- Repeated failures in a short stretch. One igniter in five years is normal wear. Three different major parts in two winters is a pattern.
- Parts that can’t be had. Some older furnaces use boards or valves that aren’t made anymore. If the only option is a used or aftermarket part we don’t trust, we’ll tell you.
- Your plans. If you’re finishing a basement, adding central air for the first time, or staying in the house for 20 more years, those facts belong in the math too.
If none of those apply, we’ll recommend the repair. If you’d like a way to think through it on your own first, our article on whether a 15-year-old furnace is worth fixing lays out the same reasoning we use. You’ll also see the common “50 percent rule” there, and why we treat it as a rough guide rather than a verdict.
How long furnaces last around here
Northwest Indiana is hard on heating equipment. Lake County furnaces run long hours from late October into April, and lake-effect cold snaps push them to run nearly nonstop for days. Plenty of furnaces still go 15 to 20 years or more with decent care. The ones that die young usually had a filter problem, a venting problem, or a furnace that was the wrong size for the house from day one. For more on what shortens or stretches that lifespan, see how long a furnace lasts in Northwest Indiana.
What goes into a replacement quote
A furnace price you get over the phone before anyone has seen the house is a guess. Ours comes after a visit, in writing, and covers what the job actually takes.
Sizing the furnace to the house
Bigger is not better. An oversized furnace heats fast, shuts off, and heats fast again, which wears parts, swings the temperature, and wastes gas. We size the new furnace to the house: square footage, windows, insulation, how the ductwork is laid out. A 1950s Hammond bungalow with plaster walls and a 1990s Crown Point two-story don’t need the same furnace, even at the same square footage.
Efficiency: 80 percent vs. 90-plus
Furnaces are rated by AFUE, the share of the fuel that turns into heat in your house. Standard units sit around 80 percent and vent up the existing chimney. High-efficiency units run in the 90s and vent through PVC pipe out a side wall, which means new venting and a condensate drain. The higher-efficiency unit costs more up front and less every month. Whether it pays back depends on your gas bill, your house, and how long you’ll stay. We’ll price both when both make sense. ENERGY STAR publishes the efficiency criteria if you want to compare models on your own.
The stuff around the furnace
A replacement is more than a box swap. The quote spells out what else the job needs: venting changes, a new gas connection, a condensate line or pump, a return-air fix if the old one was undersized, a new thermostat if the old one won’t work with the new furnace, and hauling away the old unit. If something in the house needs attention, like a chimney liner or a duct that’s falling apart, it goes on the sheet as its own line so you can see it.
Heat pump, furnace, or both
More people ask us about heat pumps every year. In a Northwest Indiana winter, an all-electric heat pump can struggle on the coldest nights, and a lot of homeowners here end up with a dual-fuel setup: a heat pump for spring and fall, and a gas furnace that takes over when it’s truly cold. That can make sense if you’re replacing the AC at the same time. It doesn’t always. We’ll give you our honest read on your house, and our heat pumps page and the article on heat pump or furnace for an Indiana winter go deeper.
What the install day looks like
- Before. You have the written price. We confirm a day and give you a window. If it’s January and you’re without heat, we’ll talk through ways to keep the house warm until then.
- Arrival. Floors get covered on the path to the furnace. The gas is shut off and the old unit comes out.
- Install. New furnace set, venting, gas, electrical, drain and thermostat connected, and ductwork transitions sealed.
- Testing. We check gas pressure, combustion, temperature rise and airflow, and run it through several full cycles.
- Walkthrough. We show you the filter, the switch, and what the thermostat does. The final bill matches the sheet you signed.
The worst time to buy a furnace
It’s the night it dies in January. You’re cold, the kids are in sweatshirts, and anything that gets heat back on sounds fine. That’s exactly when people agree to things they’d never agree to in September.
So we’ll say this plainly: if your furnace just quit, call for a repair first. Most of the time a repair gets you through the winter or much longer. If the tech finds something that truly can’t be fixed safely, you’ll know why, and you’ll still see both numbers. And if you’re reading this in the fall because the furnace is getting up there, a fall tune-up is a cheap way to find out where it stands before the cold decides for you.
Where we do replacements
We install furnaces across the same area we repair them, about 20 miles around Munster: Highland, Hammond, Dyer, Schererville, St. John, Griffith, Crown Point, Merrillville, Hobart, East Chicago, Whiting, Cedar Lake, and Lansing and Calumet City in Illinois. The full list is on our service area page. If the furnace is out right now, start at furnace repair instead.
Get both numbers
Call (219) 555-0142 or use the form below. We’ll come out, look at what you’ve got, and hand you a sheet with a repair price and a replacement price. No pressure, no expiring offer. The sheet will still be good next week.
