Estimate a repair range by suspected fault, furnace age, service timing, and access—then compare the evidence, safety checks, warranty, and repair-versus-replacement boundary.
Direct answer
Furnace repair commonly starts with a $90-$250 diagnostic visit. Ignition, sensor, switch, thermostat, or control work may bring a complete repair into roughly the $180-$1,500 range, while blower, inducer, gas, venting, heat-exchanger investigation, difficult access, or emergency service can exceed $2,000. Require a diagnosis before treating any range as a quote.
Furnace Repair Cost by Fault
Repair category
Planning range
Evidence to request
Diagnostic or service call
$90-$250
Written symptoms, fault codes, measurements, credited fee policy, and the next authorized step.
Igniter or flame-sensing issue
$180-$750
Failed-part diagnosis, ignition sequence, flame signal or related testing, labor, and part warranty.
Thermostat, switch, or control board
$250-$1,300
Voltage, signal, safety-circuit, compatibility, programming, and final operation checks.
Blower motor, capacitor, or wheel
$450-$1,900
Motor type, amperage, capacitor, wheel condition, static pressure, filter, airflow, and commissioning.
Draft inducer or pressure fault
$550-$1,900
Inducer, pressure switch, vent, condensate, combustion-air, and startup findings.
Gas valve, combustion, or venting scope
$350-$2,200+
Gas pressure, combustion analysis, vent condition, safeties, permit responsibility, and written exclusions.
Repair or Replace the Furnace?
No single age or repair-cost percentage decides every job. Use the diagnosed failure, safety, repeat history, part availability, warranty, comfort, and complete written scope.
Situation
Decision path
Require before deciding
Isolated repair on a younger furnace
Repair may be reasonable
Confirmed failed part, stable heat exchanger and venting, warranty, and completed safety checks.
Repeated faults or unavailable major part
Price both options
Repair life expectancy, part lead time, full replacement scope, and no pressure deadline.
Heat-exchanger or combustion-safety concern
Stop and diagnose
Qualified inspection and written safety findings before operation or repair authorization.
Older furnace plus major blower, inducer, gas, or vent work
Compare replacement
Separate repair and replacement proposals with permits, venting, airflow, startup, and warranty.
Furnace Repair Quote Checklist
Identify the failed part and the measurements, fault codes, or inspection evidence supporting the diagnosis.
State whether the diagnostic fee is separate, credited to approved work, or included in the repair total.
List part number, labor, permit responsibility, return visits, and separate parts and labor warranty terms.
Record gas pressure, temperature rise, combustion, venting, condensate, safeties, and final startup checks when applicable.
Separate emergency fees, access labor, code corrections, ductwork, electrical work, and thermostat changes.
Request a written replacement option when the repair is safety-critical, repeatedly failing, or expensive relative to the remaining system life.
Many furnace repairs plan from roughly $180-$1,500 after diagnosis, while blower, inducer, gas, venting, control, access, or emergency work can move the total higher. A service call alone may be roughly $90-$250. Final pricing requires an onsite diagnosis and written part, labor, safety, and warranty scope.
Does a furnace diagnostic fee include the repair?
Not always. Some contractors credit the service-call or diagnostic fee toward approved work, while others charge it separately. Ask for the policy and the amount in writing before authorizing parts or labor.
Should I repair or replace an old furnace?
Age alone does not decide. Compare the diagnosed fault, safety, part availability, repeat failures, warranty, efficiency, comfort, venting, airflow, and the complete repair and replacement scopes before deciding.
Can a cracked heat exchanger be repaired?
Treat a suspected heat-exchanger problem as a safety diagnosis, not an ordinary price item. Stop operation when instructed and request qualified inspection, written findings, and manufacturer or code-compliant options before authorizing work.
Why does emergency furnace repair cost more?
After-hours work can include dispatch availability, overtime, travel, temporary stabilization, limited parts access, and a return visit. Ask which emergency charge is separate from diagnosis and permanent repair.
Methodology
The estimator organizes broad repair allowances by suspected fault, diagnostic fee, age, service timing, and access. It does not diagnose a furnace or replace combustion, gas, venting, carbon-monoxide, or code testing by a qualified professional. Last updated October 7, 2026.
