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Furnace Not Producing Heat
in Columbus, GA
When your furnace runs but blows cold air, something is stopping the heating process before warm air reaches your rooms. Columbus homes built before 1985 often have older furnaces with heat exchangers that have cracked from years of thermal stress. Left alone, you get no heat and possibly carbon monoxide leaking into living spaces.
Quick Answer
The furnace turns on but no warm air comes out. In Columbus, this often happens because the heat exchanger cracks after years of running hard through our humid summers and cold snaps. A technician needs to check the heat exchanger, flame sensor, and gas valve. Call (762) 275-8579 before temperatures drop below freezing overnight.
Telltale Signs
Warning Signs to Watch For
- Furnace kicks on and the blower runs, but the air from vents is room temperature or cold
- Thermostat is set to heat but the house temperature keeps dropping
- Furnace cycles on and off every few minutes without warming the house
- Pilot light or igniter glows but the burners never fully light
- You smell a faint gas odor near the furnace when it tries to start
- The furnace shuts itself off shortly after starting, then tries again
Root Causes
What Causes Furnace Not Producing Heat?
Cracked Heat Exchanger
The heat exchanger is the metal chamber that keeps combustion gases away from your breathing air. In Columbus, furnaces run hard during cold snaps in December and January, then sit idle all summer in high humidity, and that repeated heating and cooling cracks the metal over time.
The Fix
Heat Exchanger Replacement
A cracked heat exchanger cannot be patched safely. The unit needs a new exchanger or full furnace replacement, depending on age. This fix stops carbon monoxide from getting into your air supply.
Failed Flame Sensor
The flame sensor is a small rod that tells the furnace a flame is actually burning. When it gets coated with residue after years of use, it stops reading the flame correctly and the furnace shuts down as a safety measure within seconds of starting.
The Fix
Flame Sensor Cleaning or Replacement
A technician cleans or swaps out the sensor, which is a straightforward fix. Once the sensor reads correctly, the furnace stays lit through a full heating cycle.
Faulty Gas Valve
The gas valve controls fuel flow to the burners. Valves on furnaces built in the 1990s in the Midland area and other older Columbus neighborhoods often stick or fail electrically, cutting gas flow before the burners can heat up.
The Fix
Gas Valve Replacement
The old valve is removed and a matched replacement is installed. Gas line connections are checked for leaks before the system is tested.
Self-Diagnosis
Which Cause Applies to You?
Check the signs you're observing to narrow down the likely root cause before your inspection.
| What You're Seeing | Cracked Heat Exchanger | Failed Flame Sensor | Faulty Gas Valve |
|---|---|---|---|
| Furnace shuts off within 10 seconds of starting every time | |||
| Visible soot or dark staining around the furnace cabinet | |||
| Burners never ignite even though the igniter glows | |||
| Carbon monoxide detector alarming when furnace runs | |||
| Furnace lights briefly then shuts down repeatedly |
Free Inspection
Get a Diagnosis in Columbus
An on-site inspection is the only way to confirm which cause applies to your property. Free, no obligation.
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Serving Columbus & surrounding areas
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