When the Temperature Drops, Your Heater Shouldn’t

Texas winters may not be long, but when the temperature finally dips, you depend on your heater to work perfectly. Unfortunately, the first cold nights often reveal problems that went unnoticed all summer.

After months of sitting idle, your furnace or heat pump can develop issues that affect performance, safety, and efficiency. The good news? Most of these heating problems are preventable—and fixable—when caught early.

Here are the most common heating problems Dallas homeowners face in fall and winter, and how to make sure you stay warm all season long.

1. Heater Blowing Cold Air

When you turn on the heat and get cold air instead, it’s a clear sign something’s wrong.

Common causes include:

• Incorrect thermostat setting (still set to “cool”)

• Clogged or dirty air filter

• Pilot light or ignition failure

• Low refrigerant in heat pumps

If your system runs but doesn’t warm the home, shut it off and schedule a heating repair. Running it in this condition can cause damage or higher utility bills.

Related: Top Signs Your AC Needs Repair

2. Uneven Heating Throughout the House

Some rooms warm up quickly while others stay cold—sound familiar? Uneven heating is often caused by:

• Leaky ductwork

• Poor insulation

• Blocked vents

• Failing blower motor

Since many homes in Dallas and Mesquite use combination HVAC systems, issues like these can affect both heating and cooling. Regular duct inspections can identify and fix the problem.

Learn more about airflow issues: Why Your Home’s Air Quality Depends on Your HVAC

3. Strange Noises from the Furnace

A healthy HVAC system runs quietly. If you start hearing banging, squealing, or rattling when your heater turns on, it could mean:

• Loose internal parts

• Worn blower belt

• Failing motor bearings

• Airflow obstruction

Ignoring these sounds can lead to complete system failure. A quick tune-up or minor repair now can prevent a big breakdown later.

4. Heater Won’t Turn On

If your heater won’t start at all, check the basics first:

• Make sure the thermostat is on heat mode.

• Replace thermostat batteries if needed.

• Check the breaker box for a tripped circuit.

If everything looks fine and it still won’t start, it could be a faulty igniter, flame sensor, or control board—issues that need professional repair.

5. Short Cycling (Heater Turning On and Off Too Quickly)

Short cycling happens when your heater runs for a few minutes, shuts off, then starts again. This constant on-and-off cycle wastes energy and stresses the system.

Possible causes:

• Dirty air filter

• Blocked vents

• Malfunctioning thermostat

• Overheating system due to restricted airflow

Replacing the air filter and scheduling an inspection can usually resolve this before it causes expensive wear and tear.

6. Burning or Musty Smells

A slight burning smell when you first turn on the heater in fall is normal—it’s usually dust burning off. But if the smell lingers or you detect:

• A strong electrical or metallic odor

• A musty or moldy smell

…it’s time to shut off the system and call a technician. Electrical smells can indicate wiring issues, while musty odors often mean mold or mildew in the ducts.

Related: Dust and Allergens in Dirty Ducts | Dallas Duct Cleaning Experts

7. Weak Airflow or Low Heat Output

If your system is running but producing little air or heat, the issue could be:

• A failing blower fan

• Clogged air filter or ducts

• Frozen evaporator coil

• Leaky ductwork

This not only reduces comfort—it forces your heater to work harder, raising energy bills and risking a breakdown.

8. Thermostat Issues

Your thermostat controls how your HVAC runs. If it’s outdated, miscalibrated, or malfunctioning, it can cause your heater to:

• Cycle irregularly

• Blow cold air

• Never reach set temperatures

Replacing your thermostat or upgrading to a programmable one can help improve both comfort and efficiency.

9. Pilot Light or Ignition Problems

Gas furnaces rely on a steady pilot light or electronic ignition to start heating. If the pilot won’t stay lit, the culprit could be:

• A dirty sensor

• Drafty conditions

• Gas supply issues

Never attempt to fix gas-related problems yourself—call a licensed HVAC professional for safe service.

10. Skyrocketing Energy Bills

If your energy bill jumps suddenly without extra usage, your heating system may be running inefficiently. Dirty filters, worn parts, or airflow restrictions are the most common culprits.

An HVAC tune-up before the cold season ensures your system is clean, lubricated, and working efficiently—saving you money all winter long.

Related: How HVAC Tune-Ups Help You Save Money

Frequently Asked Questions (FAQ)

Q: Why does my heater blow cold air sometimes?
A: The thermostat, pilot light, or air filter could be to blame. If none of these fix the issue, it may be a deeper mechanical problem that requires repair.

Q: How often should I service my heater in Texas?
A: Once per year—ideally every fall before the heating season begins.

Q: Can dirty air ducts affect my heater’s performance?
A: Absolutely. Dust and debris restrict airflow and reduce heating efficiency. Professional duct cleaning helps your system run better and improves air quality.

Q: Why does my heater make noise?
A: Noises often come from loose parts or worn components. It’s best to have a professional inspect it to prevent major damage.

Q: How can I lower my heating bill this winter?
A: Change your air filter monthly, schedule a fall tune-up, seal leaks, and keep vents unblocked for better airflow.

Stay Warm and Worry-Free This Winter

Don’t wait for the first freeze to find out your heater isn’t working. Schedule a professional inspection or repair before the temperature drops.

Call LTX Air Services at (469) 260-0226 or book your appointment online for fast, reliable heating repair and maintenance in Dallas, Mesquite, Garland, Rockwall, and nearby areas.