When Lansing winters dip into single digits, or even below zero, reliable heat isn’t a luxury; it’s a necessity. So when your furnace suddenly starts blowing cold air during extreme weather, it’s enough to make any homeowner panic.
Cold air from vents in winter can mean something minor and fixable, or it can point to a serious safety issue that requires shutting the system down right away. Knowing the difference can help protect your home, your comfort, and your safety.
Minor Issues That Can Cause Cold Air
Some causes of a furnace blowing cold air with no heat are relatively minor. These are safe first steps homeowners can check on their own. If cold air continues after these steps, it’s time to call a professional for Lansing furnace repair.
Thermostat Issues
Thermostat settings are one of the most common and easiest fixes.
- The fan may be set to “On” instead of “Auto,” causing the blower to run even when the furnace isn’t heating
- The temperature setting may be too low
- Weak or dead thermostat batteries can prevent proper signals to the furnace
Switching the fan to “Auto” and replacing batteries often solves the issue quickly.
Dirty or Clogged Air Filter
During extreme cold, furnaces run longer and harder than usual. A dirty filter can restrict airflow, causing the system to overheat.
- Overheating triggers a safety switch that shuts off the burners
- The blower keeps running, pushing cold air through the vents
- This is especially common during prolonged cold snaps
Replacing the air filter is a simple step that can restore proper operation.
Furnace Overheating
Long runtimes in subzero Lansing weather can push older or poorly maintained systems too hard.
- The furnace may short-cycle
- You may feel bursts of warm air followed by cold air
- Ongoing overheating can damage internal components
If this keeps happening, professional service is needed to prevent bigger repairs.
Duct Problems
Ductwork plays a significant role in heat delivery, especially in older Michigan homes.
- Leaks allow cold air to enter the system
- Poor insulation cools the air before it reaches your rooms
- Ducts in basements, attics, or crawl spaces are especially vulnerable
These issues don’t always stop heat production, but they can make it feel like your furnace is blowing cold air.
Serious Issues That Require Immediate Attention
Some problems are unsafe to ignore. If you suspect any of the issues below, shut off your furnace and call a professional right away.
Failed Limit Switch
The limit switch protects your furnace from overheating.
- A failure can cause constant cold air
- Internal temperatures may become unsafe
- This is not a DIY repair
A technician is needed to safely diagnose and replace the switch.
Gas Furnace Ignition Problems
If the blower runs but the burners don’t ignite, cold air will blow through the vents.
- Igniter or flame sensor failures
- Gas supply issues
- Repeated ignition attempts can be dangerous
These problems require professional repair to avoid safety risks.
Cracked Heat Exchanger
This is one of the most dangerous reasons a furnace blows cold air.
- Cracks can allow carbon monoxide to leak into your home
- Warning signs include soot, strange smells, headaches, or nausea
- The furnace must be shut off immediately
A cracked heat exchanger is a serious safety issue and should only be handled by a licensed HVAC professional.
Why Acting Quickly Matters in Lansing Winters
Lansing winters can turn dangerously cold fast. When a furnace starts blowing cold air, indoor temperatures can drop quickly, especially in older homes with basements, crawl spaces, or less insulation. That can lead to frozen pipes, water damage, and uncomfortable living conditions in a short amount of time.
Call Hager Fox for Emergency Heating Repair
If your furnace is blowing cold air or not heating at all, it’s best to have it checked right away. Hager Fox Heating & Air Conditioning has served Lansing since 1941 with licensed, background-checked, NATE-certified technicians. All work is done by our own team, never subcontractors.
At the first sign of trouble, contact Hager Fox for heating repair in Lansing.
