What Furnace Maintenance Can Help If Cold Air Is Blowing from Furnace
When winter temperatures arrive in Granite City Illinois, your furnace becomes one of the most important systems in your home. If it suddenly starts blowing cold air instead of steady heat, it can quickly create discomfort and concern. Because heating systems account for a significant portion of household energy use, any drop in performance may also lead to higher utility bills. Before assuming a major repair is needed, there are several common causes you can check first.
Check Your Thermostat
Start with the thermostat, as this is often the simplest fix. Make sure the system is set to Heat and that the fan setting is on Auto rather than on. When the fan is set to On, it runs continuously, even when the furnace is not actively heating. This can push unheated air through your vents between heating cycles. Also take a moment to:
- Replace thermostat batteries if needed
- Verify the temperature setting is higher than the current room temperature
- Confirm recent programming changes
If you recently upgraded to a smart thermostat and problems began shortly afterward, the issue may be related to compatibility or installation settings.
Check Your Pilot Light or Ignition System
If you have a gas furnace, an issue with the ignition system may be preventing heat production. Older heating systems use a continuously burning pilot light to ignite the burners. If it has gone out, the system cannot generate heat. For older units:
- Confirm the pilot light is lit
- Follow manufacturer instructions for safely relighting it
- Ensure the gas supply valve is open
If the pilot light repeatedly goes out, there could be a faulty thermocouple or gas control problem that requires professional attention. Newer high efficiency furnaces use electronic ignition systems and flame sensors. A dirty or malfunctioning flame sensor can cause the furnace to shut down shortly after starting, resulting in cold air from the vents. This part is typically inspected and cleaned as part of a yearly furnace maintenance service in Granite City Illinois.
Check Your Air Filter
A clogged air filter is a frequent reason furnaces stop working properly. When airflow becomes limited, the system can overheat and activate a built in safety switch that shuts it down. Once the system cools down, it may restart, creating inconsistent heating cycles and periods of cool airflow.
Signs of a clogged filter include:
- Weak airflow from vents
- Uneven room temperatures
- Increased energy bills
- Frequent cycling on and off
Replacing your air filter every one to three months during the heating season helps maintain proper airflow and system efficiency.
Check Your Air Ducts
If your furnace seems to be running normally but rooms still feel cold, the issue may involve your ductwork. Leaks, disconnected sections, or damaged ducts can allow cold air from attics or crawl spaces to mix with heated air before it reaches your living areas. Inspect visible duct sections for:
- Loose connections
- Gaps or cracks
- Crushed or sagging areas
- Excess dust near joints
Properly sealed and insulated ductwork improves comfort and can increase overall heating efficiency.
Check Your Oil Filter If You Have an Oil Furnace
For homes with oil heating systems, a clogged oil filter may be restricting fuel flow and limiting heat output. Replacing a dirty oil filter can sometimes restore proper function. If cold air continues after replacement, additional components such as the fuel pump or nozzle may require service.
When to Call a Granite City Illinois Furnace Professional
If you have worked through these troubleshooting steps and your furnace is still blowing cold air, it is time for a professional inspection. A trained technician can evaluate the heat exchanger, test electrical connections, clean ignition components, measure airflow, and confirm that safety systems are operating correctly. Routine furnace maintenance in Granite City Illinois helps prevent unexpected breakdowns, improves energy efficiency, and extends the life of your heating system.
If your furnace is not keeping your home comfortable, contact Dixon Heating and Cooling today to schedule service and restore reliable winter warmth in Granite City Illinois.