A furnace that stops heating may need something as simple as a new filter or flame sensor—or something as expensive as a blower motor or heat exchanger. Because several furnace problems produce similar symptoms, an accurate diagnosis is essential before approving a major repair.
In the United States, furnace repair typically costs between $133 and $505, with most homeowners paying around $318. The broader range extends from approximately $64 to $1,475, while major repairs such as heat exchanger or variable-speed blower motor replacement can cost $2,000 to $3,000 or more.
The final price depends on the failed part, furnace type, unit age, warranty coverage, labor rates, accessibility, and whether the repair is performed during normal hours or as an emergency.
Furnace Repair Cost at a Glance
| Furnace repair or part | Typical U.S. cost |
|---|---|
| Average furnace repair | About $318 |
| Common repair range | $133–$505 |
| Broad possible repair range | $64–$1,475 |
| Diagnostic or service call | $75–$250 |
| Thermostat repair or replacement | $100–$600 |
| Ignitor replacement | $100–$500 |
| Flame sensor replacement | $80–$250 |
| Gas valve replacement | $200–$800 |
| Control board replacement | $200–$650 |
| Limit switch replacement | $150–$400 |
| Draft inducer motor | $200–$1,500 |
| Blower motor repair | $150–$450 |
| Blower motor replacement | $500–$2,300 |
| Heat exchanger replacement | $1,000–$3,000 |
| Flue pipe replacement | $400–$800 |
| Furnace tune-up | $125–$200 |
These prices include different combinations of parts, diagnosis, and labor. Variable-speed systems, proprietary components, difficult access, and high-cost metropolitan areas can push repairs above the listed ranges.
Average Furnace Repair Cost
Most routine furnace repairs cost between $133 and $505, averaging approximately $318. Small problems may be resolved for less than $150, while a major motor, coil, or heat exchanger failure can cost more than $1,000.
HVAC technicians generally charge $50 to $150 per hour for furnace labor. Companies may also apply a trip fee, diagnostic fee, or one-hour minimum before adding the cost of parts. Weekend, holiday, and late-night appointments generally cost more.
A standard furnace tune-up costs approximately $125 to $200. An inspection may cost less, but repairs discovered during maintenance are normally quoted separately.
Furnace Repair Cost by Part
Thermostat
Thermostat repair generally costs $100 to $300, while installing a replacement or upgraded smart thermostat can cost as much as $600.
A faulty thermostat may cause the furnace to:
- Run continuously
- Refuse to start
- Shut off before reaching the set temperature
- Produce uneven temperatures
- Cycle more frequently than normal
Before scheduling service, confirm that the thermostat is set to heat, replace its batteries, and check whether the temperature setting is above the current room temperature.
Ignitor
Furnace ignitor replacement usually costs $100 to $250, although some professional estimates reach $500 when additional wiring, brackets, diagnosis, or emergency labor are required.
The ignitor lights the burners in a modern gas furnace. When it fails, the blower may run without producing heat, or the furnace may repeatedly attempt to start before shutting down.
The ignitor itself may cost only $20 to $100. Most of the professional price comes from the service call, diagnosis, installation, and testing.
Flame sensor or thermocouple
Replacing a flame sensor generally costs $80 to $250. Older furnaces with standing pilot lights may use a thermocouple instead, which commonly costs $100 to $300 to replace.
These safety components verify that a flame is present before allowing gas to continue flowing. A dirty or faulty sensor may let the burners ignite for several seconds and then shut them off.
Cleaning may solve the problem when the sensor is dirty. Replacement is appropriate when the component is damaged or no longer produces a reliable signal.
Gas valve
Furnace gas valve replacement costs approximately $200 to $800.
The valve controls the flow of natural gas or propane to the burners. A technician should verify the electrical signal, gas pressure, wiring, and ignition sequence before replacing it.
Do not attempt to repair a suspected gas valve problem yourself. Leave the home and contact the gas utility or emergency services from a safe location if you smell gas.
Control or circuit board
Replacing a furnace control board generally costs $200 to $650. Rewiring can add approximately $90 to $200.
The control board coordinates the thermostat, ignitor, gas valve, blower, sensors, and safety switches. Electrical surges, moisture, damaged wiring, and age can cause it to fail.
Because another component can create symptoms that resemble board failure, request a confirmed diagnosis before approving the replacement.
Limit switch
Furnace limit switch replacement usually costs $150 to $400, including the part, diagnosis, service call, and labor.
The limit switch monitors furnace temperature and shuts down the burners when the system overheats. However, repeated limit-switch activation does not necessarily mean the switch is defective.
Common causes include:
- Dirty air filter
- Closed or blocked vents
- Failing blower motor
- Restricted ductwork
- Dirty heat exchanger
- Incorrect furnace sizing
The underlying airflow problem should be corrected before installing a new switch. Otherwise, the replacement may continue tripping.
Blower motor
Repairing a blower motor commonly costs $150 to $450. Complete replacement ranges from approximately $500 to $2,300, with variable-speed motors costing more than basic single-speed models.
The blower moves heated air through the ductwork. Signs of trouble include weak airflow, grinding noises, a burning smell, repeated overheating, or a furnace that produces heat without distributing it.
The problem may sometimes involve a less expensive capacitor, belt, relay, control board, or dirty blower wheel rather than the complete motor.
Draft inducer motor
Draft inducer motor repair or replacement costs $200 to $1,500, although many replacements fall between $400 and $1,100.
The inducer starts before ignition and moves combustion gases through the heat exchanger and vent system. Failure may cause rattling, squealing, startup problems, or pressure-switch error codes.
Because this motor is part of the combustion and exhaust system, it should be diagnosed and repaired professionally.
Heat exchanger
Heat exchanger replacement generally costs $1,000 to $3,000, making it one of the most expensive furnace repairs.
The heat exchanger separates combustion gases from the air circulating through the home. Cracks, severe corrosion, or failed seams can allow dangerous gases to enter the air stream.
Replacing a heat exchanger can require several hours of labor and significant furnace disassembly. When the furnace is more than 15 years old, comparing complete replacement with the repair is usually worthwhile.
Burners and combustion chamber
Burner repair or replacement usually costs $150 to $450. Replacing a damaged gas or oil combustion chamber generally costs $200 to $600.
Rust, soot, dirt, or poor combustion can affect burner performance. A yellow or unstable flame, delayed ignition, soot buildup, or unusual odors should be inspected promptly.
Flue pipe
Replacing a furnace flue pipe generally costs $400 to $800, depending on its material, length, condition, and accessibility.
The flue carries combustion gases outdoors. Corrosion, disconnected joints, blockages, and improper venting can create serious carbon monoxide risks.
Electric furnace heating elements
Replacing an electric furnace heating element costs approximately $125 to $400 per coil. Many electric furnaces contain two to five resistance-heating coils.
A failed element may cause reduced heating capacity, cold air from the vents, longer cycles, or higher electricity use. More than one element may need replacement when the furnace has lost a large portion of its output.
Furnace Repair Cost by Common Problem
| Furnace symptom | Possible cause | Typical repair range |
|---|---|---|
| Furnace will not turn on | Thermostat, transformer, board, switch | $100–$650 |
| Burners ignite and shut off | Flame sensor, limit switch, airflow | $80–$400 |
| Furnace blows cold air | Ignitor, gas valve, thermostat | $100–$800 |
| Weak airflow | Filter, blower motor, duct restriction | $20–$2,300 |
| Furnace short-cycles | Sensor, limit switch, thermostat, airflow | $100–$400 |
| Loud rattling or squealing | Inducer or blower motor | $200–$2,300 |
| Water around furnace | Condensate drain, pump, or pipe | $100–$400 |
| Unusual combustion odor | Burners, heat exchanger, flue | $150–$3,000 |
The same symptom can have several causes. For example, a furnace that short-cycles may have a dirty filter, faulty flame sensor, defective limit switch, oversized heating capacity, or restricted ductwork. A professional diagnosis prevents replacing a costly component that is still functional.
Gas, Electric, Oil, and Propane Furnace Repair Costs
Electric furnaces are often less expensive to repair because they do not contain burners, gas valves, ignitors, or combustion exhaust components. Their common failures involve heating elements, sequencers, relays, blowers, and electrical controls.
Gas and propane furnaces may require repairs to flame sensors, ignitors, gas valves, burners, heat exchangers, and venting systems.
Oil furnaces can be more expensive to service because they require specialized burners, fuel pumps, nozzles, combustion chambers, and chimney or flue inspections.
The exact cost depends more on the failed component than the fuel source alone.
Repair or Replace the Furnace?
Repair is generally reasonable when:
- The furnace is less than 10 to 12 years old
- The problem involves one inexpensive component
- The heat exchanger is in good condition
- The unit has a reliable service history
- The repair is covered by warranty
- Energy bills remain stable
Replacement deserves serious consideration when:
- The furnace is more than 15 years old
- The heat exchanger is cracked
- Repairs have become frequent
- Replacement parts are unavailable
- Heating bills continue increasing
- Comfort is uneven throughout the home
- A repair costs close to half the price of replacement
ENERGY STAR recommends considering replacement when a furnace is more than 15 years old, requires frequent repairs, or is accompanied by rising energy bills.
Furnace Safety: When to Shut the System Off
Turn off the furnace and seek professional help when:
- A carbon monoxide alarm activates
- You smell natural gas
- Soot appears around the furnace or vents
- The furnace produces a strong burning odor
- The heat exchanger is suspected to be cracked
- The system repeatedly trips electrical breakers
- Flames appear outside the burner area
Leave the home immediately when a carbon monoxide alarm sounds or a gas leak is suspected. Do not attempt to locate the leak or restart the furnace.
The U.S. Consumer Product Safety Commission recommends installing working carbon monoxide alarms on every level of the home and outside sleeping areas.
How to Reduce Furnace Repair Costs
- Check the filter monthly. Replace or clean it when dirty.
- Keep supply and return vents open. Blocked airflow can overheat the furnace.
- Schedule yearly maintenance. A tune-up can identify worn parts before winter.
- Replace thermostat batteries. This may solve a no-heat complaint without a service call.
- Check warranty coverage. Major parts may still be covered.
- Request written estimates. Compare diagnosis, labor, parts, and warranty terms.
- Get a second opinion on major repairs. This is especially important for heat exchangers and control boards.
- Avoid emergency timing when safe. Planned weekday repairs usually cost less.
ENERGY STAR recommends checking furnace filters monthly because restricted airflow can increase energy costs, damage equipment, and contribute to early failure.
Frequently Asked Questions
How much does furnace repair cost?
Most homeowners pay $133 to $505, with an average near $318. Major motor and heat exchanger repairs can cost $1,000 to $3,000.
What is the most expensive furnace part to replace?
The heat exchanger and variable-speed blower motor are generally among the most expensive parts. Heat exchanger replacement commonly costs $1,000 to $3,000.
How much does a furnace service call cost?
A typical diagnostic or service call costs $75 to $250. Ask whether the fee is applied toward the approved repair.
Is a furnace ignitor expensive to replace?
Ignitor replacement generally costs $100 to $250, although emergency appointments or additional wiring work can increase the price.
Is it worth repairing a 15-year-old furnace?
A minor repair may still be worthwhile. A costly motor, control board, or heat exchanger repair usually justifies comparing the price of a new furnace.
Can I repair a gas furnace myself?
Homeowners can usually replace filters and thermostat batteries safely. Repairs involving gas, combustion, electrical controls, safety switches, or venting should be handled by a qualified HVAC professional.
Conclusion
Furnace repair costs average approximately $318, with most routine jobs falling between $133 and $505. Ignitors, flame sensors, thermostats, and switches are generally among the less expensive repairs. Blower motors, draft inducer motors, heat exchangers, and major control components cost considerably more.
Before approving an expensive repair, request a written diagnosis and confirm whether the part is covered by warranty. For a furnace older than 15 years, compare the repair estimate with complete replacement—especially when the heat exchanger or variable-speed blower motor has failed.