As winter settles in across Middle Tennessee, your heating system becomes one of the most important appliances in your home. Whether you’re using a gas furnace, heat pump, or electric heating system, cold-weather performance matters—and when something goes wrong, the discomfort can be immediate.
The good news? Many of the most common winter heating problems can be fixed quickly—especially if you know what to look for.
In this guide, we’ll cover the top issues Nashville homeowners face during winter and how to prevent or fix them before they turn into costly repairs.
1. Furnace or Heat Pump Won’t Turn On
Possible Causes:
Thermostat issues
Tripped circuit breakers
Clogged air filters
Pilot light or ignition system failure (for gas furnaces)
How to Fix It:
Check your thermostat settings—make sure it’s on “heat” and the temperature is set higher than the current room temperature.
Replace thermostat batteries if applicable.
Check your breaker box for a tripped switch.
Replace your air filter if it’s dirty—restricted airflow can trigger system shutdown.
If it’s a gas furnace, make sure the pilot light is lit or the igniter is functioning.
📞 Still not starting? Call South Nashville Heating & Cooling for a full system diagnostic.
2. Blowing Cold Air Instead of Heat
Possible Causes:
Thermostat fan setting set to “ON” instead of “AUTO”
Dirty air filter causing the system to overheat and shut off the burner
Problem with the gas supply or ignition
Heat pump in defrost mode
How to Fix It:
Set thermostat fan to “AUTO”—this allows the blower to only run when the air is heated.
Replace the air filter if it’s clogged.
Check the pilot light or gas supply.
For heat pumps, understand that brief cold air during defrost mode is normal in winter.
3. Uneven Heating or Cold Spots in the Home
Possible Causes:
Leaky or unbalanced ductwork
Blocked or closed vents
Aging furnace or undersized system
Poor insulation in certain rooms
How to Fix It:
Check all vents and registers—make sure they’re open and not blocked by furniture.
Consider a zoning system or duct balancing for multi-level homes.
Have your ductwork inspected for leaks or gaps.
Add insulation in colder rooms to improve comfort.
4. Strange Noises Coming From the Furnace
Sounds to Watch For:
Banging or popping – expanding ducts or dirty burners
Squealing – worn belts or motor bearings
Rattling – loose components or panels
Grinding – serious motor or blower issues
How to Fix It:
Turn off the system and schedule a professional inspection—especially for grinding or squealing noises.
Regular maintenance helps prevent noisy operation.
🔧 Tip: Never ignore unusual sounds. Early detection can prevent major repairs later.
5. Short Cycling (Turning On and Off Frequently)
Possible Causes:
Dirty air filter
Faulty thermostat
Oversized furnace
Flame sensor issues
How to Fix It:
Replace the air filter to restore airflow.
Make sure the thermostat isn’t located near a heat source (like a sunny window).
A technician can inspect your flame sensor, clean it, or recommend system resizing if the furnace is too large.
Short cycling increases wear and tear and reduces efficiency—don’t wait to address it.
6. Rising Utility Bills with No Increase in Usage
Possible Causes:
System losing efficiency due to age or wear
Dirty filters or coils
Leaky ductwork
Low refrigerant levels in heat pumps
Poor insulation
How to Fix It:
Schedule a heating system tune-up—a technician will clean coils, test components, and inspect for leaks.
Upgrade to a high-efficiency system if yours is more than 15 years old.
Consider air sealing and insulation improvements for whole-home efficiency.
7. Carbon Monoxide Risks
Common Causes:
Cracked heat exchanger in a gas furnace
Blocked flue or exhaust pipe
Poor ventilation
Prevention:
Install carbon monoxide detectors on every floor of your home.
Schedule annual furnace inspections to catch issues early.
Never ignore symptoms like headaches, nausea, or dizziness when the heat is on.
Your safety is non-negotiable. If your CO detector alerts or you suspect a leak, turn off the system and leave the home immediately.
8. Heat Pump Struggling in Freezing Temps
Heat pumps work well in Nashville’s mild winters, but during extreme cold, they can lose efficiency.
How to Fix It:
Make sure your system has an auxiliary (emergency) heat setting.
Keep your outdoor unit free of ice and snow.
Schedule maintenance to ensure defrost mode is working properly.
For better performance in cold spells, ask about dual-fuel systems that combine a heat pump with a backup gas furnace.
Preventing Heating Problems: Routine Maintenance Is Key
Most winter heating issues are preventable with regular seasonal maintenance. At South Nashville Heating & Cooling, our tune-up includes:
Full system inspection
Burner and pilot check (for furnaces)
Heat exchanger safety check
Filter replacement
Thermostat calibration
Duct and airflow testing
CO detection testing
Routine care keeps your system running safely, efficiently, and reliably all winter long.
✅ Call South Nashville Heating & Cooling Before Problems Happen
Don’t wait for a chilly night to discover your heating system isn’t ready.
Whether you need:
Furnace or heat pump repair
System replacement
Winter tune-up
Emergency service
…we’re here to help. As Nashville’s trusted HVAC experts, we’ll keep your comfort in tune—even on the coldest days.
👉 Fill out the form below to schedule your service or seasonal inspection today.
