HVAC Troubleshooting Center
Diagnose and fix common HVAC problems with our comprehensive troubleshooting guides
Emergency Situations - Act Immediately
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Gas Smell
EMERGENCYLeave immediately, call gas company from outside
⚠️
Electrical Burning Smell
URGENTTurn off system at breaker, call technician immediately
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Carbon Monoxide Alarm
EMERGENCYEvacuate, call 911, do not re-enter
⚠️
Major Water Leak
URGENTTurn off system and water, call technician
Quick Diagnostic Tools
Troubleshooting by Problem Type
Cooling Problems
AC not cooling, freezing, or cycling issues
AC Not Cooling
Common Symptoms:
- •Warm air from vents
- •No temperature change
- •Running but not cooling
Easy to Medium$0-500
TroubleshootWater & Moisture Issues
Leaks, condensation, and drainage problems
Furnace Leaking Water
Common Symptoms:
- •Puddles near furnace
- •Rust spots
- •Water damage
Medium to Hard$100-3000
TroubleshootHeating Problems
Furnace, ignition, and no-heat issues
Furnace Flame Sensor
Common Symptoms:
- •Burner lights then shuts off in 3-10 seconds
- •Lockout after failed ignition attempts
- •Flame failure error code
Easy$0-200
TroubleshootFurnace Blowing Cold Air
Common Symptoms:
- •Cold air from vents
- •Furnace runs but no heat
- •Cycling between warm and cold
Easy to Medium$0-1000
TroubleshootCracked Heat Exchanger
Common Symptoms:
- •Yellow or flickering flame
- •CO detector alarms
- •Headaches or nausea when furnace runs
Hard$1,500-$8,500
TroubleshootElectrical & Control Issues
Power, thermostat, and control problems
Thermostat Heat On But No Heat
Common Symptoms:
- •Thermostat shows heating but house stays cold
- •Blower runs but no warm air
- •Furnace short-cycles or locks out
Easy to Medium$0-600
TroubleshootWhen to Call a Professional
Try DIY First:
- ✓Filter replacements and cleaning
- ✓Thermostat troubleshooting
- ✓Circuit breaker resets
- ✓Basic drainage clearing
- ✓Simple pilot light relighting
Call a Pro Immediately:
- ✗Gas leaks or gas smell
- ✗Electrical burning smell
- ✗Refrigerant handling
- ✗Heat exchanger issues
- ✗Major electrical repairs
Can't Find Your Problem?
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