Furnace Repair Cost by Repair Type: A Complete Component Breakdown
Different furnace problems carry very different price tags. See what each repair actually costs in 2026, from a $75 flame sensor cleaning to a $3,500 heat exchanger replacement — plus when it makes sense to repair vs. replace each component.
Most homeowners pay
Based on national averages across all repair types. Your cost depends on which component needs repair.
Furnace Repair Cost by Component (2026)
| Item | Low | High | Note |
|---|---|---|---|
| Flame Sensor (clean or replace) | $75 | $300 | Most common minor repair |
| Thermocouple | $100 | $300 | Common on standing-pilot furnaces |
| Limit Switch | $65 | $125 | Inexpensive part, quick fix |
| Capacitor | $100 | $400 | Usually fails from age |
| Hot Surface Ignitor | $150 | $400 | One of the most frequent repairs |
| Pressure Switch | $150 | $350 | Often caused by venting issues |
| Gas Valve | $200 | $1,500 | Wide range based on furnace model |
| Control Board / Circuit Board | $200 | $1,200 | Expensive part, moderate labor |
| Draft Inducer Motor | $200 | $1,500 | Commonly fails at 10–15 years |
| Blower Motor | $300 | $2,500 | Major repair, 2–4 hours labor |
| Heat Exchanger | $500 | $3,500 | Most expensive common repair |
| Diagnostic / Service Call Fee | $75 | $200 | Often credited toward repair |
Prices include parts and labor at standard business-hour rates. Emergency and after-hours service adds 50–200% to labor costs.
Minor Repairs ($75–$400)
Minor furnace repairs involve inexpensive parts and relatively simple labor. Most take under an hour to complete once the technician has diagnosed the problem.
Flame Sensor: $75–$300
The flame sensor is a small metal rod that sits in the burner flame and confirms the furnace is actually producing heat. When it gets coated with carbon buildup, it can no longer detect the flame and shuts the furnace down as a safety precaution.
When it fails: Your furnace lights briefly, then shuts off after 3–10 seconds. This is one of the most common furnace problems and often the cheapest to fix.
Repair vs. replace: A simple cleaning costs $75–$150 and works in most cases. If the sensor is cracked or corroded, a replacement sensor costs $10–$40 for the part, with total installed cost of $100–$300.
Thermocouple: $100–$300
The thermocouple serves a similar function to the flame sensor but is found on older standing-pilot furnaces. It generates a small voltage when heated by the pilot flame, keeping the gas valve open.
When it fails: The pilot light won't stay lit. You can light it manually, but it goes out within seconds of releasing the button.
Repair vs. replace: Thermocouples are always replaced rather than repaired. The part itself costs $10–$25, but labor for proper calibration and testing brings the total to $100–$300.
Limit Switch: $65–$125
The limit switch monitors the furnace's internal temperature and shuts it down if it overheats. It's a safety device that prevents fires and damage to the heat exchanger.
When it fails: The furnace cycles on and off frequently (short cycling) or the blower runs continuously without stopping.
Repair vs. replace: Limit switches are inexpensive ($5–$20 for the part) and always replaced rather than repaired. Total cost including labor is $65–$125.
Capacitor: $100–$400
The capacitor stores and releases electrical energy to start the blower motor. Think of it as a battery that gives the motor its initial jolt of power.
When it fails: The blower motor hums but doesn't start, or the furnace doesn't blow air even though you can hear it running.
Repair vs. replace: Capacitors are always replaced. The part costs $10–$50, but the total repair is $100–$400 depending on the type (start vs. run capacitor) and accessibility.
Moderate Repairs ($150–$1,200)
Moderate repairs involve more expensive parts and longer diagnostic times. These components are more complex and may require specialized knowledge of your specific furnace model.
Hot Surface Ignitor: $150–$400
The ignitor is a small ceramic element that glows red-hot to ignite the gas when your furnace starts a heating cycle. It's the most commonly replaced furnace component after the flame sensor.
When it fails: The furnace doesn't ignite at all. You may hear the inducer motor start and the gas valve click, but no ignition occurs. Some furnaces will flash an error code on the control board.
Repair vs. replace: Ignitors are always replaced. The part costs $20–$80 depending on the model, with total installed cost of $150–$400. Aftermarket ignitors that fit multiple models are available for less, but OEM parts typically last longer.
Moderate Repairs — Pressure Switch, Gas Valve, and Control Board
Pressure Switch: $150–$350
The pressure switch verifies that the draft inducer motor is creating proper airflow through the heat exchanger before allowing gas to flow. It's a safety device that prevents combustion gases from backing up into your home.
When it fails: The furnace starts its startup sequence but stops before ignition. You'll often hear the inducer motor running but the burners never light. Error codes related to pressure switch failure are among the most common.
Repair vs. replace: Sometimes the issue isn't the switch itself but a clogged condensate drain line or blocked vent pipe. A good technician will check these first. If the switch is genuinely faulty, replacement costs $150–$350.
Gas Valve: $200–$1,500
The gas valve controls the flow of natural gas or propane to the burners. It's an electronically controlled valve that opens and closes based on signals from the control board.
When it fails: The furnace goes through its startup sequence but no gas flows to the burners, or you smell gas when the furnace is off (a dangerous situation that requires immediate attention).
Repair vs. replace: Gas valves are always replaced, never repaired. The wide cost range ($200–$1,500) reflects the significant price difference between standard and high-efficiency furnace models. OEM valves for premium brands (Carrier, Trane, Lennox) cost more than generic models.
Control Board / Circuit Board: $200–$1,200
The control board is the furnace's brain. It sequences the startup process, monitors safety switches, communicates with the thermostat, and displays error codes when something goes wrong.
When it fails: Symptoms vary widely — the furnace may not respond to the thermostat, cycle erratically, display error codes, or fail at random points in the startup sequence. Intermittent problems that come and go are a hallmark of control board issues.
Repair vs. replace: Control boards are replaced, not repaired. Costs vary dramatically based on the furnace model. Standard boards run $200–$600 installed, while variable-speed and communicating boards for premium furnaces can cost $600–$1,200.
Major Repairs ($300–$3,500)
Major furnace repairs involve the most expensive components and the most labor. These are the repairs that often trigger the repair-vs.-replace decision, especially on furnaces over 10–12 years old.
Draft Inducer Motor: $200–$1,500
The draft inducer motor creates a draft that pulls combustion gases through the heat exchanger and out the exhaust vent. It runs before and during every heating cycle.
When it fails: You'll hear a loud humming, grinding, or squealing noise when the furnace starts. In some cases, the motor won't start at all, preventing the furnace from igniting.
Repair vs. replace: Draft inducer motors are replaced as complete assemblies. The part costs $100–$800, with total installed cost of $200–$1,500. On furnaces over 12 years old, this repair often pushes past the $5,000 rule threshold. For more on this calculation, see our Repair vs. Replace Guide.
Blower Motor: $300–$2,500
The blower motor drives the fan that circulates heated (and cooled) air through your home's duct system. It's one of the hardest-working components, running during both heating and cooling seasons.
When it fails: Weak or no airflow from your vents, the furnace overheats and shuts down, or you hear grinding, screeching, or rattling from the blower compartment.
Repair vs. replace: Standard single-speed blower motors cost $300–$1,000 to replace. Variable-speed (ECM) motors used in high-efficiency furnaces cost $800–$2,500. The motor type must match what your furnace requires — you can't downgrade from variable-speed to single-speed.
Heat Exchanger: $500–$3,500
The heat exchanger is the core component of your furnace. It's a set of metal chambers where combustion gases transfer heat to the air circulating through your home, while keeping those gases (including carbon monoxide) separated from your breathable air.
When it fails: A cracked heat exchanger may produce no obvious symptoms initially. Warning signs include a yellow or flickering burner flame, soot buildup inside the furnace, a strong or unusual smell when the furnace runs, and unexplained headaches or flu-like symptoms in household members.
Heat Exchanger — Repair vs. Replace
Repair vs. replace: Heat exchanger replacement is technically possible ($500–$3,500 for the repair) but rarely recommended on furnaces over 10 years old. The labor alone takes 6–10 hours, and the high cost typically makes full furnace replacement ($3,000–$8,000) the better investment. Many HVAC professionals will recommend replacement over repair for any furnace with a cracked heat exchanger that is out of warranty.
Repair vs. Replace Decision by Component
Not all repairs justify the cost. Use this framework to decide whether a repair makes financial sense for your specific situation:
| Component | Repair Cost | Replace if Furnace is... | Why |
|---|---|---|---|
| Flame Sensor | $75–$300 | Almost never worth replacing furnace | Very low cost repair |
| Thermocouple | $100–$300 | N/A — only on old furnaces | Consider upgrading furnace type |
| Ignitor | $150–$400 | Over 18 years old | Low cost, but very old furnaces have other issues |
| Gas Valve | $200–$1,500 | Over 12–15 years old | High cost triggers $5,000 rule |
| Control Board | $200–$1,200 | Over 12–15 years old | High cost, risk of other failures |
| Draft Inducer | $200–$1,500 | Over 12 years old | Often signals broader wear |
| Blower Motor | $300–$2,500 | Over 10–12 years old | Expensive repair, furnace likely aging |
| Heat Exchanger | $500–$3,500 | Over 10 years old | Safety concern, cost near replacement price |
For a personalized calculation, use our Repair vs. Replace Calculator. It factors in your furnace's age, repair cost, efficiency, and local energy prices.
For a broader overview of all furnace repair costs and pricing factors, see our Complete Furnace Repair Cost Guide.
What Affects the Cost of Each Repair
Beyond the component itself, several factors influence the final price of any furnace repair:
Parts: OEM vs. Aftermarket
OEM (Original Equipment Manufacturer) parts are made by or for your furnace's brand. They're guaranteed to fit and typically last longer, but cost 30–100% more than aftermarket alternatives. For critical components like gas valves and control boards, OEM parts are generally worth the premium. For simple items like ignitors and capacitors, quality aftermarket parts perform equally well.
Labor Time and Complexity
Labor rates for HVAC technicians range from $75 to $150 per hour depending on your location. Some repairs take 30 minutes; others take 4+ hours. The diagnostic time matters too — intermittent problems that are hard to reproduce can add an hour or more of troubleshooting.
Furnace Brand and Model
Premium brands (Carrier, Trane, Lennox) have higher parts costs than value brands (Goodman, Amana). Older and discontinued models may require special-order parts with lead times of 1–3 weeks, during which you may need a temporary heating solution.
Access and Installation Complexity
A furnace in an unfinished basement with plenty of clearance is straightforward to work on. A furnace in a tight closet, attic, or crawl space requires more time and effort, which increases labor costs by $50–$200.
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Furnace Repair Cost by Type FAQ
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