Furnace Repair Cost
Typical repair cost by component, and when to replace instead.
Compiled by DIY Repair Guide · reviewed 2026-09-09 ·how we research these
A typical furnace repair cost runs from $150 to $900 for most individual part replacements, while a basic diagnostic service call ranges between $75 and $200. At DIY Repair Guide, we compiled and checked these typical cost ranges against published heating industry data and standard contractor billing schedules across the United States.
Most furnace breakdowns involve wear items like igniters, flame sensors, or electrical connections that fail after thousands of heating cycles. More complex failures involving the blower motor, the gas valve, or the main control board sit higher on the pricing spectrum.
Labor rates vary by region. Understanding typical part and labor expenses helps you evaluate a contractor invoice before agreeing to work. It also helps you decide whether fixing an aging heating system makes financial sense or if your money is better directed toward a new heating unit.
Typical Furnace Repair Cost by Component
A straightforward furnace repair average cost ranges from $150 to $900 for common parts including igniters, control boards, gas valves, and blower motors. Labor and component pricing both factor into these totals, with surface-mounted sensors taking under an hour to replace and internal assemblies requiring extensive cabinet disassembly.
Igniters and flame sensors sit at the lower end of the expense scale because a technician can access and test them quickly. A furnace control board replacement cost or furnace gas valve replacement cost lands in the middle range due to the price of electronic boards and the precise pressure adjustments required on fuel lines.
A blower motor replacement cost typically represents the highest single routine mechanical expense on a furnace, running $300 to $900 depending on motor type. A variable-speed motor costs more than a single-speed one, which pushes those replacements toward the upper end of the range.
| Component or Service | Typical US Cost | Common Failure Symptoms |
|---|---|---|
| Basic diagnostic / service call | $75 to $200 | Furnace fails to start, short cycles, or blows cold air |
| Igniter or flame sensor replacement | $150 to $400 | Furnace clicks repeatedly, burner fails to light, or flames shut off after seconds |
| Thermostat wiring or simple electrical fault | $150 to $300 | Thermostat loses power, intermittent heating, or blown 24-volt fuse |
| Gas valve replacement | $300 to $600 | Burner assembly receives no fuel, gas odor near unit, or low burner flame |
| Control board replacement | $300 to $700 | Unresponsive system, erratic blower behavior, or diagnostic light codes |
| Blower motor replacement | $300 to $900 | Weak airflow at supply registers, screeching bearings, or overheating shutoff |
Diagnostic Service Call Charges and Fee Credits
A furnace diagnostic service call typically costs $75 to $200 and covers the technician's travel, physical inspection, and electrical testing. A technician uses this time to read error codes from the control board, test safety switch continuity, and verify line voltage.
Many heating contractors credit the diagnostic fee toward the total cost of the repair if you hire them to complete the recommended work. If you choose not to proceed with the proposed fix, you remain responsible for paying the service fee to compensate the contractor for their diagnostic time and trip expense.
Trip charges cover travel. Before scheduling a technician, ask the company dispatcher how their billing structure works and whether they apply the trip fee to approved repairs. You should also confirm whether evening, weekend, or holiday visits carry after-hours emergency surcharges. The US Department of Energy notes that keeping up with routine maintenance is what catches small, cheap failures before they turn into the larger repairs priced out above.
Cracked Heat Exchanger Hazards and Red-Tag Protocols
A cracked heat exchanger is a severe carbon monoxide (CO) safety hazard that changes a standard service call into an immediate replacement conversation. The heat exchanger forms the sealed barrier that separates toxic combustion byproducts from the fresh air circulating through your living space.
When metal fatigue, thermal stress, or rust causes a crack in this metal chamber, poisonous combustion gases can enter the supply airflow. Because of this health risk, a licensed heating, ventilation and air conditioning (HVAC) technician who discovers a crack will red-tag the equipment and shut down the gas supply on the spot rather than run it.
Welding is not an option. Repairing a heat exchanger, where even possible, often costs close to or more than the unit is worth, especially on a furnace already 15 or more years old. For that reason, this specific failure usually leads straight to a replacement conversation instead of a repair quote.
Never operate a furnace with a suspected or verified cracked heat exchanger. Doing so risks releasing lethal levels of carbon monoxide throughout your home. If a technician red-tags your heating unit, keep the equipment turned off and evaluate options for a complete heating system replacement.
Criteria for Choosing to Repair vs Replace Furnace Units
A dependable rule of thumb for deciding whether to repair vs replace furnace equipment compares the single repair quote against the installed price of a brand-new heating unit. A full new-furnace installation on this site's own furnace replacement cost page runs roughly $3,000 to $12,000 depending on fuel type and efficiency tier.
Contractors commonly evaluate the repair-vs-replace decision by checking if a single repair quote runs past roughly a third to half of what a new unit installed would cost. If the estimate crosses that threshold, replacing becomes the more defensible economic choice rather than repairing the equipment again.
Equipment age matters just as much. A furnace operates with a typical lifespan of 15 to 20 years, and units near or past the upper end of that service life yield diminishing returns on large mechanical repairs.
- Furnace under 10 years old: Repair is generally the straightforward choice unless the cabinet or heat exchanger has sustained catastrophic damage.
- Furnace between 10 and 15 years old: Repair makes sense for minor electrical faults and standard sensors, while repairs crossing toward half the replacement cost warrant getting installation estimates.
- Furnace over 15 years old: Replacement becomes the stronger financial move when a major component fails or the quote reaches one third of a new installation.
- Cracked heat exchanger: Replace the unit regardless of age, because repair expenses rarely make sense on an older chassis.
Multiple Service Calls as a Replacement Trigger
Needing a second or third repair within a single heating season is a common practical trigger for getting a replacement quote alongside the repair quote. While each individual visit for a sensor, a valve, or a motor might seem manageable on its own, recurring breakdowns indicate widespread mechanical fatigue across the system.
Frequent failures during winter also create compounding heating downtime and risk leaving your home unheated during severe freezes. Weighing the cost of yet another temporary fix against a new heating system gives you a clearer view of long-term reliability.
When a technician presents a repair quote on a furnace that has already required multiple service calls this winter, ask for an itemized replacement estimate before authorizing further work.
Common questions
How much does it cost to fix a furnace that won't turn on?
Fixing a furnace that will not start typically costs between $75 and $400 for common issues like a blown fuse, a tripped safety switch, a dirty flame sensor, or a failed igniter. If the shutdown stems from a failed control board or gas valve, total repair expenses can range from $300 to $700.
Is it worth repairing a 15-year-old furnace?
Repairing a 15-year-old furnace makes sense for inexpensive fixes like an igniter, flame sensor, or simple wiring repair running $150 to $400. If the repair involves a blower motor, gas valve, or control board costing $300 to $900, or if the unit has broken down multiple times in one season, replacing the furnace is usually the more defensible choice because the equipment sits at the upper end of its 15 to 20 year typical service life.
How much does a furnace diagnostic visit cost?
A furnace diagnostic service call typically costs $75 to $200. This fee compensates the heating technician for traveling to your home, inspecting safety mechanisms, reading system fault codes, and testing electrical circuits. Many contractors credit this diagnostic charge toward the repair bill if you approve their quote.