What drives the price
Like AC work, the bill starts with a diagnostic fee. Common failures are inexpensive parts — a flame sensor is often under $30 — so you are largely paying for the expertise to identify the failure and the safety verification afterward.
- Which part failed (flame sensor and igniter are cheap; blower motor and control board are not)
- Gas vs electric
- Whether a combustion safety test is included
- Winter emergency scheduling premiums
- Access — attic and crawlspace furnaces cost more in labor
Should you DIY this or call a professional?
Call a pro. A gas furnace burns fuel inside your home and vents combustion gases; a mistake here produces carbon monoxide, not just discomfort. The one genuinely safe homeowner check is the air filter — a clogged filter causes overheating and short cycling and accounts for a meaningful share of no-heat calls.
Signs you need this repair
- Blowing cold air or not igniting
- Short cycling on and off repeatedly
- Yellow rather than blue burner flame
- Banging or squealing at startup
- Carbon monoxide detector alarm — leave the house and call from outside
How to not get overcharged
Ask for the specific part name and number that failed. Then ask what the part costs versus the labor. A $30 flame sensor billed as a $450 repair may still be fair for the diagnostic expertise, but you deserve to see the split, and knowing it gives you real ground to negotiate on.
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Red flags to watch for
- A cracked heat exchanger diagnosis without showing you photo or camera evidence
- Immediate replacement pressure paired with a same-day discount deadline
- No combustion or CO test after working on a gas appliance
Frequently asked questions
How much does it cost to repair a furnace?+
Furnace repairs typically cost $150-$700, averaging about $400. Igniters and flame sensors are on the cheap end; a cracked heat exchanger usually means replacing the furnace.
Can I repair a furnace myself, or should I hire a professional?+
Call a pro. A gas furnace burns fuel inside your home and vents combustion gases; a mistake here produces carbon monoxide, not just discomfort. The one genuinely safe homeowner check is the air filter — a clogged filter causes overheating and short cycling and accounts for a meaningful share of no-heat calls.
How long does it take to repair a furnace?+
1-3 hours for common repairs. Scheduling and parts availability can extend the overall timeline beyond the hands-on work itself.
What makes the price of this job go up or down?+
Which part failed (flame sensor and igniter are cheap; blower motor and control board are not). Gas vs electric. Whether a combustion safety test is included. Winter emergency scheduling premiums. Access — attic and crawlspace furnaces cost more in labor.
How do I avoid being overcharged?+
Ask for the specific part name and number that failed. Then ask what the part costs versus the labor. A $30 flame sensor billed as a $450 repair may still be fair for the diagnostic expertise, but you deserve to see the split, and knowing it gives you real ground to negotiate on.