Furnace Repair Cost Calculator
Find out what a furnace repair should cost in 2026 — before the technician hands you the invoice. Diagnose your symptom, price the part, add emergency fees, check your warranty, and run the $5,000 repair-vs-replace rule.
Planning estimates based on published 2025–2026 US national cost ranges (parts + labor + $89 diagnostic visit). Not a quote and not professional advice — always get 2–3 written estimates from licensed HVAC contractors. If a carbon-monoxide alarm sounds, leave the house and call emergency services first.
The industry rule of thumb: repair quote × furnace age. Over $5,000 — or over 50% of a new furnace — and replacement usually wins.
How furnace repair pricing actually works
Every furnace repair invoice is built from the same four line items: the part, the labor to install it, a diagnostic / service-call fee (typically $89), and a timing surcharge if the tech comes after hours. Understanding which line item dominates your bill is the difference between accepting a quote and negotiating it.
The part is what creates the enormous spread in "average furnace repair cost" figures you see online. A flame sensor is a $15–$50 component and the whole job averages $290; a heat exchanger is a $700–$2500 component buried deep inside the cabinet, and the job averages $2,339. When a single national "average" blends a $290 sensor swap with a $2,339 exchanger replacement, the number means nothing — which is why this calculator prices by part, not by vague average.
Labor is the second lever. Most single-part swaps take one to two hours, but motors and exchangers require real disassembly: a blower motor job averages $1,039 largely because of the labor, and control-board work ($639 typical) includes testing and reprogramming time. Labor is also the only line item that moves with when you call — parts cost the same at 2 a.m., but labor carries a 1.5× after-hours uplift (capped at $300), 1.25× on weekends and 1.75× on holidays.
Where you live moves labor too. Our estimator applies a regional index drawn from published cost guides: Northeast 1.15×, Midwest 1.0×, South 0.95×, West 1.10×. The same blower motor job runs about $1,182 in the Northeast versus $992 in the South — a $190 swing for identical work.
Warranty status is the most overlooked lever. A manufacturer's parts warranty (usually 10 years, often requiring registration) zeroes out the parts line: a $639 control-board job falls to about $389. An installer's labor warranty zeroes out labor instead. With both, you typically pay only the $89 diagnostic visit. Check both warranties before you approve a quote — techs will not always ask.
Finally, know when a repair stops being worth it. The industry uses the $5,000 rule (repair quote × age in years; over $5,000 → replace) alongside the 50% rule (repair over half the price of a new furnace → replace). A $2,339 heat-exchanger repair is already 52% of a $4,500 replacement — the math points at a new unit even on a young furnace. Run your own numbers in the $5,000-rule tab above.
Furnace repair cost by part — 2026 reference table
Typical installed ranges (parts + labor + $89 diagnostic visit), Midwest baseline, regular hours. Use the estimator tab for your region, timing and warranty.
| Part | Typical part cost | Typical labor | Installed range |
|---|---|---|---|
| Hot-surface ignitor | $40–$90 | $110–$310 | $239–$489 (typ. $364) |
| Flame sensor | $15–$50 | $85–$250 | $189–$389 (typ. $290) |
| Thermostat | $50–$250 | $70–$200 | $209–$539 (typ. $374) |
| Start/run capacitor | $15–$60 | $90–$190 | $194–$339 (typ. $267) |
| Pressure switch | $30–$80 | $120–$220 | $239–$389 (typ. $314) |
| 24V transformer | $20–$60 | $80–$190 | $189–$339 (typ. $264) |
| Gas valve | $100–$450 | $150–$300 | $339–$839 (typ. $589) |
| Control board | $100–$400 | $200–$400 | $389–$889 (typ. $639) |
| Draft inducer motor | $200–$700 | $200–$500 | $489–$1,289 (typ. $889) |
| Blower motor | $200–$900 | $200–$600 | $489–$1,589 (typ. $1,039) |
| Flue pipe / venting | $100–$300 | $300–$500 | $489–$889 (typ. $689) |
| Heat exchanger | $700–$2500 | $300–$1000 | $1,089–$3,589 (typ. $2,339) |
Worked example 1: dead ignitor, after-hours call
The situation
A 9-year-old gas furnace in Ohio clicks but never lights on a Tuesday night. The symptom checker points at the hot-surface ignitor as most likely.
- Part + labor (midpoint): ignitor part ≈ $65, labor ≈ $210.
- After-hours uplift: labor × 1.5 → +$105 emergency adder (under the $300 cap).
- Diagnostic visit: +$89.
- Total: $65 + $210 + $105 + $89 = $469 — exactly what the estimator shows.
- $5,000 rule: $364 × 9 years = $3,276 — well under $5,000 → repair.
Verdict: approve the repair. Had they waited until morning, the same job would have been $364 — the after-hours premium was $105.
Worked example 2: cracked heat exchanger on an old furnace
The situation
A 14-year-old furnace shows yellow, lazy burner flames. The tech diagnoses a cracked heat exchanger and quotes $2,339.
- Repair estimate check: our estimator's typical heat-exchanger job is $2,339 (range $1,089–$3,589) — the $2,339 quote sits inside the published range, so it is not inflated.
- $5,000 rule: $2,339 × 14 years = $32,746 — far over $5,000 → replace.
- 50% rule: $2,339 is 52% of a $4,500 new furnace — over half → replace.
- Safety: a cracked exchanger can leak carbon monoxide. Do not run the furnace until it is fixed or replaced.
Verdict: do not spend $2,339 repairing a 14-year-old unit — price a new furnace with our furnace replacement cost calculator.
Practical tips to avoid overpaying
Many companies waive the $89 visit fee if you approve the repair on the spot. Ask before they start, not after.
Parts warranty (manufacturer, ~10 years) and labor warranty (installer) are separate. A covered control board drops from $639 to about $389.
After-hours labor costs 1.5×. If the house is safe and warm enough, a morning call saves the $105-style premium.
Ask to keep the old ignitor, sensor or board. It proves the swap happened and lets a second tech verify the diagnosis.
Quotes far above the installed ranges above deserve a second bid — especially for motors and boards, where markups vary most.
Those are not pricing problems; they are safety emergencies. Leave the house, call emergency services, then call HVAC.
Not what you're looking for?
Deciding between repair and replacement? This tool estimates the repair bill — the HVAC repair vs replace calculator scores your furnace's age, efficiency and breakdown history to recommend which move wins.
Pricing a brand-new furnace? See furnace replacement cost for 2026 installed prices by AFUE tier, size and fuel type.
Sizing a furnace for your home? That is a different question entirely — see the furnace size calculator.
Frequently asked questions
How much does furnace repair cost in 2026?
Most single-part furnace repairs fall between $189 and $1,589 all-in (parts, labor and the diagnostic visit). The fixes technicians see most often are small: a flame sensor averages $290 and a hot-surface ignitor averages $364. Mid-size repairs like a control board ($639) or gas valve ($589) land in the middle, while a blower motor ($1,039) or heat exchanger ($2,339) can exceed $1,000. After-hours calls add an emergency surcharge. These are planning estimates from published national ranges, not quotes — always get 2 to 3 written estimates.
How much does it cost to replace a furnace ignitor?
A hot-surface ignitor replacement typically costs $364 all-in, with a realistic range of $239 to $489 depending on the part brand and local labor rates. The part itself is inexpensive ($40–$90); most of the bill is the service call and labor. It is the single most common furnace repair — if your furnace clicks but never lights, the ignitor is the first suspect. Use the symptom checker above to confirm before you call a technician.
How much does flame sensor replacement cost?
Flame sensor replacement averages $290, ranging from $189 to $389. The sensor is a $15–$50 part, but accessing and testing it takes most of the visit. The classic symptom is a furnace that fires up and then shuts off within a minute. Because the fix is cheap, it is almost always worth doing: a $290 repair on a 15-year-old furnace scores $4,350 on the $5,000 rule — well under the threshold — so repair wins even on an old unit.
How much does it cost to replace a blower motor?
Blower motor replacement averages $1,039 all-in ($489 to $1,589). Standard PSC motors sit at the low end; variable-speed ECM motors push toward the high end. Prices also vary by region: the same job averages about $1,182 in the Northeast versus $992 in the South in our estimator. Loud grinding noises or weak airflow from the vents are the telltale symptoms.
How much does a furnace control board cost to replace?
Control board replacement averages $639 ($389 to $889). Power surges are the usual killer, which makes a $30 surge protector cheap insurance. If your board is still under the manufacturer's parts warranty (typically 10 years, and registration is often required), you pay labor and the diagnostic visit only — about $389 instead of $639. Check your warranty status in the estimator above before you approve any quote.
How much does heat exchanger replacement cost?
Heat exchanger replacement averages $2,339, ranging from $1,089 to $3,589 — the most expensive common furnace repair. Because the part alone can exceed half the price of a new furnace, most professionals apply the 50% rule: a $2,339 repair is already 52% of a $4,500 replacement, so replacement usually wins the math. A cracked exchanger can also leak carbon monoxide, so treat yellow burner flames or a CO alarm as an emergency, not a quote request.
How much extra do emergency or after-hours furnace repairs cost?
Expect an after-hours labor uplift of 1.5x (capped at $300 per visit), 1.25x on weekends (capped at $200) and 1.75x on holidays (capped at $350). A concrete example: an ignitor repair that costs $364 during regular hours runs about $469 after hours (including a $105 emergency adder) or $417 on a weekend. If the house is safe and warm enough to wait, holding out until morning is the cheapest repair there is. On a holiday, a major job like a heat exchanger can reach $2,689 (including a $350 emergency adder).
What is the typical furnace diagnostic or service-call fee?
Most companies charge $89 for the diagnostic visit. Many waive or credit it if you approve the repair on the spot — always ask before they start work. Our estimator includes the fee in every total so the numbers match what the invoice actually looks like.
Does a warranty cover furnace repair costs?
A manufacturer's parts warranty (usually 10 years, and you often must register the unit) covers the part but not the labor: a control board drops from $639 to about $389. An installer's labor warranty covers labor but not parts (about $339 for the same board). With both warranties active, you typically pay only the diagnostic visit ($89). Neither covers damage from neglect, so keep up annual maintenance.
What is the $5,000 rule for furnace repair?
Multiply the repair quote by the furnace's age in years: if the result tops $5,000, replacement is usually the smarter money. Examples from our repair-vs-replace tab: a $600 repair on a 12-year-old furnace scores $7,200 — replace. A $364 ignitor repair on an 8-year-old furnace scores $2,912 — repair. A $500 repair at exactly 10 years hits $5,000, the threshold itself, so get a second quote before deciding either way.
Why do furnace repair quotes vary so much by region?
Labor rates dominate the difference. Our estimator applies a regional index (Northeast 1.15x, Midwest 1.0x, South 0.95x, West 1.10x): a blower motor job that averages $1,039 in the Midwest runs about $1,182 in the Northeast and $992 in the South. Big-city quotes also skew higher than rural ones within the same region, and emergency timing stacks on top.
Should I repair or replace my furnace?
This tool estimates what the repair should cost. For the actual repair-vs-replace decision, use our dedicated HVAC repair vs replace calculator, which scores age, efficiency and breakdown history — and if replacement wins, our furnace replacement cost calculator shows 2026 installed prices. Quick rule of thumb: under 10 years old with a sub-$500 repair, fix it; over 15 years old with a four-figure repair, price a new unit.
Cost ranges: typical published US national installed estimates (parts + labor), 2025–2026. Methodology and sources: below.
Methodology & sources
Part and labor ranges are a consensus of published 2025–2026 national cost guides (see SOURCES.md in our build notes): where guides disagreed, we used the overlapping range rather than any single outlier. Totals add parts + labor + a $89 diagnostic visit. "Typical (mid)" is the estimate at the midpoint part and labor values — not a separate survey figure. Regional multipliers (NE 1.15×, MW 1.0×, South 0.95×, West 1.10×) reflect the labor-cost spread reported across guides. Emergency uplifts apply to labor only and are capped per visit. Warranty handling follows standard industry terms: parts warranties cover parts, labor warranties cover labor, and the diagnostic visit is usually still charged.
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