Furnace repair, diagnosis and cost
Heating faults, ignition problems, and what a repair really costs.
- Will not start
- Ignitor and flame sensor
- Short cycling
- Repair vs replace
Latest
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Boiler vs Furnace: Cost, Efficiency and Comfort Compared (2026) A furnace blows heated air through ducts; a boiler pumps hot water to radiators. What each costs installed, which wastes less fuel, and when switching pays. Updated -
How Long Does a Furnace Last? Repair or Replace an Old One (2026) Most furnaces last 15 to 20 years and some reach 30. What wears one out early, how to date yours, and when an old furnace is worth repairing or replacing. Updated -
Furnace Short Cycling? Find Why It Keeps Shutting Off (2026) Furnace short cycling? Watch when the burners go out to tell a dirty flame sensor from an overheating limit, a sagging vent pipe or an oversized furnace. Updated
Troubleshooting
9 articlesSymptom first, cause second. Start here when something has stopped working.
- Boiler vs Furnace: Cost, Efficiency and Comfort Compared (2026) A furnace blows heated air through ducts; a boiler pumps hot water to radiators. What each costs installed, which wastes less fuel, and when switching pays. Updated
- How Long Does a Furnace Last? Repair or Replace an Old One (2026) Most furnaces last 15 to 20 years and some reach 30. What wears one out early, how to date yours, and when an old furnace is worth repairing or replacing. Updated
- Furnace Short Cycling? Find Why It Keeps Shutting Off (2026) Furnace short cycling? Watch when the burners go out to tell a dirty flame sensor from an overheating limit, a sagging vent pipe or an oversized furnace. Updated
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Furnace Smells Like Burning? What Each Smell Means (2026) Furnace smells like burning? Tell first-run dust from a clogged filter, melting plastic, an electrical fault or gas, and know which ones mean shut it off. Updated -
Furnace Leaking Water? Find the Source and Fix It (2026) Furnace leaking water? Check the vent pipe first, then the condensate trap, drain hose, pump, AC coil and humidifier, in order, before you call anyone. Updated -
Furnace Blowing Cold Air? 8 Causes, Checked in Order (2026) Furnace blowing cold air? Rule out the normal causes first, then check the fan setting, filter, limit switch, flame sensor, ignitor and inducer, in order. Updated -
Emergency Furnace Repair: What to Do Before You Call (2026) Furnace out at night or on a weekend? When it is a real emergency, six checks that can save an after-hours fee, what it costs, and how to stay warm safely. Updated -
Furnace Making Loud Noise? What Each Sound Means (2026) Roaring, rumbling, rattling, squealing, humming, clicking or banging: what each loud furnace noise means, what you can fix, and when to shut it off. Updated -
Furnace Not Turning On? 10 Causes, Checked in Order (2026) Furnace not turning on? Read the error code first, then work 10 causes in order: thermostat, power, filter, flame sensor, ignitor, gas, vent and more. Updated