Repair or Replace Your Furnace? How We Decide
Short answer. It depends on what broke and how old the furnace is. A single failed part on a furnace under about 15 years old is usually worth repairing. At 15 years and older, or when the same problem keeps coming back, we usually recommend replacing it. Repairs on a furnace typically run from about $150 to $700, and a new furnace starts at $3,300 installed for an 80% model and $4,400 for a 96% model.
Key facts
- 80% gas furnace
- from $3,300 installed
- 96% gas furnace
- from $4,400 installed
- Our rule
- under 15 years: usually repair; 15 and older: replace
- Install time
- usually 1 to 2 days
- Old furnace
- removal and haul-away included
Prices from our published price list, valid through December 31, 2026. Your quote is itemized after a free in-home assessment.
I am Vlad, I own EverHeat and I often come out to these calls myself. This is the same reasoning I walk homeowners through in their basement or garage.
The three questions that decide it
1. How old is the furnace?
Look for the label inside the front panel; the manufacturing date is usually there or coded in the serial number. Our rule of thumb:
- Under 10 years: repair almost always. The rest of the furnace has plenty of life left.
- 10 to 15 years: repair, unless the repair is a large share of the replacement price.
- 15 years and older: we usually recommend replacing. Parts get harder to find, efficiency is behind current models, and the next failure is rarely far away.
2. What actually failed?
Some parts are cheap and routine: a filter, a flame sensor, a capacitor, a thermostat. Others are major: the control board, the blower motor, the inducer. And a few failures on an old furnace are a clear signal to replace rather than repair. We tell you which group your problem is in before you spend anything; the diagnostic visit is free.
3. Is this the first repair or the third?
A furnace that needed a part last winter, another one in spring and now a third call is telling you something. In a Tacoma home the heating had been failing for more than a year through repeated visits from other companies. We traced the cause, and replacing the system was the real fix.
The numbers side by side
Repair ranges from our online calculator, and starting prices for a new furnace from our price list:
| Repair | Typical range |
|---|---|
| Furnace not turning on | $150 to $700 |
| Error code | $150 to $550 |
| Noise | $130 to $500 |
| New furnace, installed | Starting price |
|---|---|
| 80% AFUE gas furnace | from $3,300 |
| 96% AFUE gas furnace | from $4,400 |
| Replacing the furnace together with a heat pump install | +$3,300 (80%) or +$4,500 (96%) |
A simple way to read it: if a single repair on a 15 year old furnace costs a large part of a new 80% furnace, put that money toward the replacement instead.
Furnace Cost See your price range
80% or 96%: which replacement?
Both burn natural gas and heat the house the same way. The difference is how much of the gas ends up as heat in your home.
- An 80% furnace vents hot exhaust up a metal flue, usually the one you already have. It costs less to install.
- A 96% furnace pulls more heat out of the exhaust, so it vents cooler gases through plastic pipe and produces water that needs a drain. It costs more up front and less to run.
In Bellevue we replaced a furnace that was over 15 years old with a 96% American Standard furnace (Bellevue job). When a remodel moved the furnace in an Auburn home, the job included new ductwork, new venting and a new thermostat. The longer you plan to stay, the more the 96% model pays back.
How a replacement goes
- Free in-home assessment. We size the furnace to the house rather than swapping like for like, check venting, gas line and ducts, and give you an itemized quote.
- Permit. We pull the permit before work starts.
- Install. Usually 1 to 2 days, including removal and haul-away of the old furnace.
- Inspections. Two after the install, mechanical and electrical, and every job has to pass.
- Warranty. 10 years on the equipment from the manufacturer, 20 years on the gas furnace heat exchanger (99 on some models), and 3 years on our labor.
In Renton we replaced a furnace ahead of a sale or remodel. If you are selling, a replacement like this fits before closing: one to two days, inspection included. Renton job
Signs a furnace is near the end
Age is the main signal, but these usually show up first:
- Repairs are becoming a habit, a call every season or two.
- Some rooms never warm up even though the furnace runs for a long time.
- New noises: banging at start up, rattling or squealing that was not there before.
- The furnace starts and stops often without the house reaching the set temperature.
- Your gas bill climbs from one winter to the next without a change in how you live.
None of these alone means replace it today. Together, on a furnace past 15 years, they usually do.
What a replacement quote should include
Ours lists every line before any work starts, and any quote you compare should do the same:
- The furnace itself: efficiency (80% or 96%), size and brand.
- Removal and haul-away of the old unit. Ours always includes it.
- Venting: reusing the existing flue for an 80% furnace, or new plastic venting and a condensate drain for a 96% furnace.
- Gas and electrical connections to the new furnace.
- Thermostat: keep the one you have if it is compatible, or a new one.
- Permit and inspections, pulled and booked by us.
- Warranty terms in writing: equipment, heat exchanger and labor.
If a line is missing, ask about it before you sign, not after.
A third option: moving the furnace
Sometimes the question is not repair or replace, but where. During a remodel in Auburn the furnace had to make room, so we moved the existing Rheem furnace to a new spot in two days, with new ductwork, new venting and a new thermostat. The same age rule applies: a younger furnace is usually worth moving, while one 15 years old or more is better replaced with a new one in the new spot. We price both at the assessment so you can compare. Auburn job
When replacing is the wrong answer
Not every old furnace has to go the moment something breaks. If the furnace is 12 years old, the failed part is a flame sensor and everything else checks out, replacing it would be selling you something you do not need yet. We would rather fix it and tell you what to plan for.
Get a straight answer
Book a free in-home assessment and we will tell you whether yours is a repair or a replacement, with prices for both.
FAQ
Is a 20 year old furnace worth repairing?
Usually only for a small, cheap repair to get you through the season while you plan a replacement. For anything major, put the money toward a new furnace.
Will my existing air conditioner work with a new furnace?
Often yes, if the AC is in good shape. We check it at the assessment.
Should I add a heat pump when I replace the furnace?
It is worth considering, because doing both at once costs less than two separate jobs. We compare the options in Heat Pump or Gas Furnace.
Do you take the old furnace away?
Yes. Removal and haul-away are part of every replacement.
How do I know a replacement quote is fair?
Our prices are published and every quote is itemized line by line. You can check your range on furnace installation cost before we come.
Related: Furnaces · Furnace installation cost · Heating repair · Furnace not heating
What changed: October 25, 2026: Published.
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