Most furnace repairs cost about $318 to $350. HomeAdvisor’s data puts the average at $318 with a full range of $64 to $1,475, and HomeGuide-based 2026 price guides land at roughly $350 on a $100 to $1,500 range. The failure mode is the cheap-looking visit that turns into a four-figure quote: one failed igniter is a $100 to $250 problem, a cracked heat exchanger is not.
Below is what each common furnace repair costs, which fees come before the repair, and how to decide whether the part is worth buying. Prices come from Angi, HomeAdvisor, and HomeGuide-sourced lists, and we say where they disagree.
Furnace Repair Cost by Part
The sources split into two lists. Angi gives wide ranges across the most common parts:
| Part | Cost range (Angi) |
|---|---|
| Furnace filter | $1 - $35 |
| Flame sensor | $150 - $250 |
| Thermostat | $100 - $600 |
| Blower motor | $150 - $2,000 |
| Draft inducer motor | $200 - $1,500 |
| Gas valve | $200 - $600 |
A second set of 2026 price guides, which cite HomeGuide, adds components Angi’s list lacks and narrows the inducer range:
| Part | Cost range (HomeGuide-based) |
|---|---|
| Flame sensor | $80 - $250 |
| Igniter | $100 - $250 |
| Control board | $300 - $650 |
| Draft inducer motor | $400 - $1,100 |
| Heat exchanger | $1,000 - $3,000 |
Angi’s separate heat exchanger figure ($100 to $1,500) conflicts with the HomeGuide-based $1,000 to $3,000. We use the higher range for planning, because a heat exchanger swap is labor-heavy and often the point at which replacing the furnace is cheaper.
Two patterns stand out. The parts that fail most often, such as the flame sensor, igniter, and thermostat, are cheap. The expensive parts, such as the blower motor, inducer motor, and heat exchanger, are less common, but they are where the range stretches into four figures.
Fees That Come First
Labor runs $50 to $150 per hour, according to both Angi and the HomeGuide-based guides, and the bill usually adds a trip or diagnostic charge plus any emergency surcharge. Angi recommends budgeting a yearly furnace tune-up at $150 to $200 and swapping filters about every 90 days. Our annual HVAC maintenance guide breaks down what a $90 to $220 visit should and should not include.
The cheapest repair is the one that doesn’t happen at 9 p.m. on a freezing Saturday. Emergency calls can add a surcharge on top of the repair, so a furnace that is short-cycling in October is worth a weekday visit before cold weather.
The Three Symptoms Behind Most Calls
It won’t ignite or shuts off after a few seconds. The usual suspects are a dirty or failed flame sensor ($80 to $250 per the lists above), a failed igniter ($100 to $250), or a clogged condensate drain on high-efficiency units.
It runs but the house doesn’t warm up. A failed blower motor, a clogged filter, or a failing thermostat. Check the filter first, which costs $1 to $35 and is not a service call.
Strange noises or error codes. Often the inducer motor or control board, which are the mid-priced repairs ($300 to $1,100 in the HomeGuide-based lists). Error codes are logged by the control board, so ask the tech which code they read and what it points to.
Repair or Replace Your Furnace
Three tests help here.
Age. ENERGY STAR lists a furnace or boiler older than 15 years as a replacement candidate, and notes that a qualified new furnace is 15% more efficient than a conventional one. It also flags frequent repairs combined with rising energy bills as a sign efficiency has slipped.
The 50% rule. A common guideline is to replace when the repair costs more than half of a new unit. Our gas furnace replacement guide puts a new installed furnace at $4,000 to $9,500, so half is $2,000 to $4,750 (our arithmetic).
The $5,000 rule. Multiply the furnace’s age by the repair quote. Over $5,000, start collecting replacement quotes. It is a contractor rule of thumb, not a standard, but it lines up well with the age threshold above.
Four Worked Examples
These are illustrative scenarios built from the ranges above, not customer quotes.
| Scenario | Repair cost | Age | Age x cost | Share of $4,000-$9,500 new furnace | Verdict |
|---|---|---|---|---|---|
| Igniter, midpoint | $175 | 11 yrs | $1,925 | 2% to 4% | Repair |
| Control board, midpoint | $475 | 14 yrs | $6,650 | 5% to 12% | Judgment call |
| Inducer motor, midpoint | $750 | 16 yrs | $12,000 | 8% to 19% | Lean replace |
| Heat exchanger, midpoint | $2,000 | 12 yrs | $24,000 | 21% to 50% | Replace |
The heat exchanger row is the one that matters. At the range endpoints, a $1,000 to $3,000 repair is about 11% to 75% of the replacement range (our arithmetic), and the repair does not fix the other 12 years of wear. A cracked heat exchanger is also a safety issue, because it can let combustion gases into the air stream. Carbon monoxide alarms on every level of the house are not optional with an older gas furnace.
How to Pay Less
- Make the quote itemize. Part, part price, labor hours, and trip fee as separate lines. Anything bundled as “furnace repair” is hard to compare, as covered in contractor quote red flags.
- Change the filter first. At $1 to $35 it is the cheapest fix in this guide, and a clogged filter can cause overheating shutdowns.
- Book the tune-up in early fall. Angi’s $150 to $200 yearly tune-up is far cheaper than a no-heat emergency.
- Get a second opinion on heat exchanger diagnoses. It is the one call where a wrong answer costs either thousands or your safety, so a second inspection is cheap insurance.
- Don’t count on federal help. The federal tax credit for efficient gas furnaces expired at the end of 2025. Check state and utility rebates at dsire.org.
When the Furnace and AC Are Both Aging
If the furnace is past 15 and the AC is past 10, a major furnace repair is a signal to price both together. Our HVAC system replacement cost guide covers the combined job, and AC repair cost covers the cooling side. If you are weighing gas against electric for the next system, read heat pump vs. gas furnace and run the heat pump payback calculator with your own utility rates.
Bottom Line
Plan on roughly $100 to $650 for the common fixes (sensor, igniter, thermostat, control board) and $400 to $3,000 when a motor or heat exchanger is the culprit. Run the age-times-cost number on any quote above $1,000, get the failure itemized, and give a heat exchanger diagnosis a second opinion before you buy.
FAQ
How much does a furnace service call cost?
Fees vary by company and we found no neutral national figure for the call-out alone. Labor is typically $50 to $150 per hour, and most companies add a trip or diagnostic fee plus any after-hours surcharge. Ask for the total fee and whether it is credited toward the repair before they arrive.
Is it worth repairing a 20-year-old furnace?
For a small part like a sensor or igniter, sometimes. ENERGY STAR already flags furnaces past 15 years for replacement, so a repair above a few hundred dollars on a 20-year-old unit mostly buys time. Apply the $5,000 rule: at age 20, any repair over $250 clears the threshold (our arithmetic).
Why does my furnace keep shutting off?
Common causes are a dirty filter, a dirty flame sensor, an overheating limit switch, or a failing inducer motor. Start with the filter. If it keeps happening after a fresh filter, a technician should read the control board’s error code.
Can I replace a furnace part myself?
Changing a filter is routine homeowner work. Anything involving the gas valve, burners, or venting should be done by a licensed technician, because mistakes can cause gas leaks or carbon monoxide exposure, and many jurisdictions require a licensed contractor for gas appliance work.