Furnace Repair Cost in 2026: What Common Fixes Cost

Last updated: July 2026 · Based on 2026 US contractor pricing

Furnace repair costs $150 to $650 for most common fixes, with the national average around $300. But the range runs from a $15 flame sensor you can clean yourself to a $2,000 heat exchanger that often means replacing the whole furnace. Knowing what each repair should cost — and which you can do yourself — is the difference between a fair bill and an expensive surprise on a cold night. This guide breaks down every common furnace repair by price, explains what drives the cost, and helps you decide when repair stops making sense.

Furnace Repair Cost by Part (2026)

The Cheap Fixes (Often DIY)

Before assuming the worst, know that the most common furnace “repairs” are cheap or free. A dirty flame sensor — the number one no-heat culprit — costs nothing to clean and $80–$200 if a tech does it. A clogged air filter causing overheating and short cycling is a $20 fix. A failed thermostat is $100–$350 installed but often a simple swap. If your furnace is acting up, always start with these before paying for a major diagnosis — see furnace not turning on for the free checks.

The Mid-Range Repairs

These are the repairs that need a technician but are usually well worth doing on a furnace under 15 years old. The hot surface igniter ($150–$300) is a common wear part that cracks and fails after several years. A capacitor ($100–$250) is a small but critical component that can stop the blower or inducer. The pressure switch or limit switch ($150–$350) are safety controls that may need replacing if they fail rather than simply responding to airflow problems. And the inducer motor ($300–$600) draws combustion gases and will stop the furnace if it fails.

The Expensive Repairs

A few repairs cost enough to make you weigh replacement. The blower motor ($400–$700) moves the heated air; a variable-speed model costs more. The gas valve ($300–$750) controls fuel flow. The control board ($400–$700) is the furnace’s brain. And the heat exchanger ($1,000–$2,000+) is the big one — a cracked heat exchanger is both expensive and a carbon monoxide hazard, and on an older furnace it usually signals it is time to replace the whole unit rather than repair.

What Drives the Cost

• The part itself: a $15 flame sensor versus a $500 control board.
• Labor and diagnosis: most shops charge a $90–$180 diagnostic fee, which may apply toward the repair.
• Emergency or after-hours: a no-heat call on a winter night or weekend costs a premium.
• Brand and access: premium-brand parts and hard-to-reach installations cost more.
• Your region: labor rates vary widely between markets.

Repair or Replace?

A useful rule: if the repair cost times the furnace’s age exceeds $5,000, lean toward replacement. A $400 repair on a 14-year-old furnace ($5,600) says replace; the same repair on a 5-year-old unit ($2,000) says fix it. Always replace — never repair — a cracked heat exchanger regardless of age, because of the carbon monoxide risk. See how long a furnace lasts to judge where yours stands, and get a second opinion before authorizing any repair over $500 on an aging furnace.

How to Save on Furnace Repair

• Do the free checks first — filter, thermostat, breaker, and flame sensor — before paying for a visit.
• Read the furnace’s error code so you and the technician know the likely part.
• Check your warranty — many furnaces carry 10-year parts coverage if registered.
• Ask that the diagnostic fee apply toward the repair, and request the part number.
• Prevent repairs with annual furnace maintenance — far cheaper than emergency fixes.

FAQ

How much does furnace repair cost on average?

Most furnace repairs run $150–$650, with a national average near $300. Simple fixes like a flame sensor or capacitor are under $200, while a blower motor, gas valve, or control board runs $400–$800. A heat exchanger is $1,000+ and often means replacing the furnace.

Is it worth repairing a furnace?

Usually yes if the furnace is under 15 years old and the repair is minor to moderate. Replace instead if repair cost times age exceeds about $5,000, if the heat exchanger is cracked, or if repairs are becoming frequent on an aging unit.

What is the most expensive furnace repair?

The heat exchanger, at $1,000–$2,000+. Because a cracked heat exchanger is also a carbon monoxide hazard and usually appears on older furnaces, it typically makes more sense to replace the entire furnace than to repair it.

Why is my furnace repair so expensive?

Major components like the blower motor, gas valve, control board, or heat exchanger are costly parts, and labor plus a diagnostic fee adds up. Emergency or after-hours winter calls and premium-brand parts push the price higher.