There’s nothing more stressful than turning on your furnace in the middle of a Minnesota winter and getting no heat. A cold home can mean frozen pipes, health concerns, and a whole lot of discomfort. While some furnace issues are minor and easy to fix, others require professional attention.

At Gray Duct Heating, Cooling & Air Duct Cleaning, we help Minneapolis homeowners stay safe and warm with trusted furnace repair, maintenance, and replacement services. If your furnace isn’t working, here are 10 common causes to check before you panic.

1. Thermostat Issues

Start simple. If your thermostat is set incorrectly or the batteries are dead, your furnace may not know when to turn on.

What to do: Make sure it’s set to “heat” and the temperature is higher than your current room temp. Replace batteries if it’s unresponsive.

2. Tripped Breaker or Blown Fuse

Your furnace needs power to run. If the breaker has tripped or a fuse is blown, the unit won’t operate.

What to do: Check your electrical panel. If the furnace breaker is flipped, reset it once. If it trips again, call a technician.

3. Dirty or Clogged Air Filter

A dirty filter restricts airflow and can cause the system to overheat and shut down.

What to do: Change your filter monthly during the heating season. Better airflow means better performance and fewer repairs. Our heating maintenance services include routine filter checks.

4. Pilot Light or Ignition Failure

Older systems use a pilot light. Newer ones have electronic igniters. If either fails, your furnace can’t produce heat.

What to do: Check if the pilot is lit. If not, relight it carefully or call a pro. Ignition issues often require furnace repair.

5. Gas Supply Problems

No gas means no heat. The main shutoff valve may be closed, or your utility provider may be experiencing issues.

What to do: Ensure the gas valve is open and other gas appliances are working. Never try to fix gas lines yourself. If in doubt, contact a licensed technician immediately.

6. Dirty or Faulty Flame Sensor

This small part detects the flame. If it’s dirty or malfunctioning, it will shut down the burner for safety.

What to do: Cleaning or replacing the sensor is part of our professional heating repair services.

7. Blower Motor Malfunction

The blower distributes warm air. If it fails, you won’t feel heat even if the furnace is running.

What to do: If you hear humming or clicking but no airflow, the blower may need repair or replacement.

8. Blocked or Leaky Air Ducts

Sometimes the furnace works fine but heat isn’t reaching your rooms. Duct problems could be the culprit.

What to do: Check for cold spots, rattling sounds, or visible damage. We provide full residential HVAC services including duct inspections.

9. Clogged Condensate Line

High-efficiency furnaces create condensation that must drain. If the line clogs, your furnace may shut off.

What to do: If you see water pooling near your furnace or a drain pan, call for service. This is a common issue in humid basements.

10. Furnace Is Too Old

Furnaces typically last 15 to 20 years. Frequent breakdowns, rising energy bills, or uneven heating may mean it’s time for a new unit.

What to do: If your furnace is near the end of its life, we can help with heating replacement and heating installation options that improve comfort and efficiency.

When to Call a Professional

Some issues can be resolved with a quick check. Others require the expertise of a licensed technician. At Gray Duct Heating, Cooling & Air Duct Cleaning, we provide honest, thorough heating services in Minneapolis for everything from minor repairs to full system replacements.

As a veteran-owned, fully licensed company, we’re committed to keeping your home safe and warm all winter long.

If your furnace isn’t working, don’t wait. Schedule your service today and get heat restored fast.