Furnace Repair Cost
Reviewed 2026-07-30
Typical range
$150 – $2,000
National average
$400
Furnace Repair cost breakdown
| Line item | DIY cost | Professional cost |
|---|---|---|
| Igniter or flame sensor replacement | $20 – $50 part, moderate risk | $150 – $300 |
| Blower motor replacement | $150 – $400 part, high DIY risk | $400 – $900 |
| Gas valve replacement | Not legal without gas-fitting license | $300 – $700 |
| Heat exchanger replacement | Not recommended — safety/carbon monoxide risk | $1,000 – $2,000 |
| Thermostat or control board replacement | $50 – $150 part, low-moderate risk | $150 – $450 |
| Ductwork or venting repair tied to the furnace | Limited to sealing accessible joints | $200 – $600 |
What pushes furnace repair cost up
- Heat exchanger cracks, which pose a carbon monoxide risk and require careful diagnosis
- Gas valve or control board failures needing manufacturer-specific parts
- Older furnaces (15+ years) with discontinued parts
- Emergency winter calls during cold snaps
- Furnace located in tight attic or crawl space access points
- Combined issues, such as blower failure plus a clogged filter causing overheating
- Homes on propane requiring different regulator and valve parts
What brings furnace repair cost down
- Simple igniter, flame sensor, or thermostat fixes caught early
- Enrolling in a seasonal maintenance plan that discounts repairs
- Furnace still within manufacturer's parts warranty period
- Off-season scheduling in late summer or early fall
- Easy, unobstructed access to the furnace closet or basement unit
Furnace Repair diagnostic and emergency fees
$75 – $150, frequently waived or credited if repairs proceed
No-heat emergency calls in freezing weather often add $100 – $250 in after-hours fees, and parts availability can be tighter during peak winter demand.
Questions to ask before you approve furnace repair work
- Could this be a cracked heat exchanger, and how do you test for it safely?
- Is the failed part still under manufacturer warranty?
- Do you carry the part on your truck, or will I need to wait for it to ship?
- Is my furnace's age a reason to consider replacement instead?
- Will you check for carbon monoxide as part of this repair?
- What's included in the diagnostic fee if I don't proceed with repair?
Furnace Repair cost questions
How do I know if my furnace needs repair or replacement?
If the furnace is over 15 years old and the repair costs more than a third of a new unit, most technicians recommend replacement rather than continued repairs.
Is a cracked heat exchanger dangerous?
Yes — it can leak carbon monoxide into your home's air supply and should be treated as a safety issue requiring immediate professional evaluation and possible furnace shutdown.
Why does furnace repair cost more in winter?
Demand spikes during cold snaps, so many companies add after-hours or emergency surcharges and parts can take longer to source during peak season.
Problems furnace repair solves
- Why Is My House So Cold?
- Why Is My House Getting a Furnace That Blows Cold Air?
- Why Is My House Getting Weak Airflow From the Vents?
- Why Is My House Getting High Energy Bills?
Sources for these furnace repair costs
- U.S. Consumer Product Safety Commission, Carbon Monoxide guidance
- ASHRAE Handbook — HVAC Applications
- ENERGY STAR Furnace guidance