Switching Seasons: How to Prepare Your HVAC System for Heating

October in North Texas often sits between two seasons. Warm afternoons can still make the air conditioner useful, while a passing cold front may leave the house feeling much cooler the following morning. That sudden shift is usually when homeowners start thinking about turning the heat back on.

Before switching the thermostat, though, the heating system should get some attention. In many homes, the furnace or heat pump has been inactive since March or April. Over that time, dust can build up around burners or heat strips, batteries in thermostats and safety alarms can weaken, and stored belongings may slowly collect around the equipment.

Checking these items early can make the seasonal change much easier. A small issue found during mild October weather is far less stressful than the same problem appearing during a cold December night.

Lewisville homeowners also benefit from preparing before the month ends. Average daytime highs typically fall from the mid 80s at the beginning of October toward the low 70s later in the month, while the possibility of the first frost begins to rise near the final days of October.

TexAire Heating & Air Conditioning  regularly helps Lewisville homeowners prepare furnaces and heat pumps for this transition. The checklist below separates the simple checks homeowners can safely handle themselves from the situations that are better left to a professional HVAC technician.

The purpose is to make sure the system is ready before winter arrives and to help homeowners recognize problems before they become urgent.

Why October Is the Right Time to Run Through This Checklist

October provides a useful testing period before the heating system becomes essential.

If a furnace refuses to start during a mild afternoon, homeowners still have time to arrange service while indoor conditions remain comfortable. If the same failure happens during a freezing January night, the situation becomes much more serious.

Fall also gives homeowners a better chance to schedule repairs before demand for heating service increases.

Lewisville's changing temperatures add another reason to prepare early.

A cool morning may require heating, while the same home could need air conditioning later that afternoon.

That frequent switching can put more demand on thermostats, heat pumps, and HVAC controls.

Running through a pre-season checklist helps confirm that the system is ready for these changing conditions.

10 Things to Check Before Switching From AC to Heat

1. Replace the Air Filter

After months of summer use, the HVAC filter may be filled with dust, pollen, pet hair, and other debris.

By October, even a filter that does not look completely clogged may already be restricting airflow.

Poor airflow makes the furnace or heat pump work harder to move warm air throughout the home.

In gas furnaces, that restriction can also cause the heat exchanger to operate at a higher temperature than intended.

If the system gets too hot, safety controls may shut it down before the cycle is complete.

Installing a clean filter of the correct size before heating season begins gives the system a better chance to operate efficiently and safely.

Most standard 1-inch filters should be replaced every 1 to 3 months.

Thicker media filters generally last longer, but they still need regular inspection.

2. Confirm Thermostat Settings and Batteries

The thermostat should be checked before assuming there is a problem with the furnace or heat pump.

Many early-season "no heat" issues are caused by incorrect settings or weak batteries.

Change the thermostat mode from Cool to Heat.

Then raise the temperature a few degrees above the current indoor reading.

Wait several minutes for the system to start.

If the screen is dim or blank, replace the batteries first.

Smart thermostats may still be following summer schedules.

Away modes, eco settings, vacation programs, or cooling schedules can interfere with normal heating operation.

Homes with heat pumps should also confirm that the thermostat is configured correctly for heat pump use.

An incorrect setup can cause backup electric heat to run more often than necessary.

Auto mode may also lead to frequent switching during October.

Because temperatures can change so much between morning and afternoon, many homeowners prefer selecting Heat or Cool manually until the weather becomes more consistent.

3. Test Smoke and Carbon Monoxide Alarms

Carbon monoxide cannot be seen or smelled.

That makes working alarms especially important in homes with gas furnaces, gas water heaters, or attached garages.

Test every carbon monoxide alarm before regular heating begins.

Replace weak batteries and confirm that alarms near sleeping areas and on each level of the home are working properly.

The age of the detector should also be checked.

Many carbon monoxide alarms have a service life of around 5 to 7 years.

The manufacture date is usually printed on the back.

If a carbon monoxide alarm sounds, everyone should leave the home immediately.

Call 911 from outside once everyone is safely away.

4. Clear the Area Around the Furnace

The space around a furnace can easily become a storage area during the warmer months.

In Lewisville homes, furnaces are commonly located in garages, hallway closets, or attics.

Boxes, decorations, cleaning supplies, paint cans, and other items may gradually end up too close to the equipment.

Combustible materials should not be stored near a gas furnace.

They can create a fire risk, while fumes from certain chemicals may affect proper combustion.

The furnace also needs enough open space for airflow and service access.

Remove anything placed directly against the unit and keep several feet of surrounding space clear whenever possible.

If the system is installed in an attic, make sure the walkway to the equipment is clear too.

That gives technicians safer access when maintenance or repair is needed.

5. Open and Clear Supply Vents and Return Grilles

Heating problems can sometimes begin with something as simple as a blocked vent.

Furniture may be sitting in front of a return grille.

A rug may cover a floor register.

Some supply vents may have been closed during the cooling season.

Before using the heat, inspect the vents throughout the home.

Supply registers should be open so warm air can reach each room.

Return grilles also need clear space so air can travel back toward the HVAC system.

Blocked returns can contribute to uneven heating and rooms that stay colder than others.

Open any closed vents and move objects that restrict airflow.

Vacuuming dust from vent covers and return grilles can also help reduce the dusty smell that often appears during the first heating cycle.

6. Inspect the Outdoor Heat Pump Unit

Homes with heat pumps need to keep the outdoor unit clear even after summer ends.

A heat pump uses the same outdoor equipment for cooling and heating.

That means airflow around the condenser remains important throughout winter.

Leaves, grass clippings, weeds, and overgrown shrubs can restrict airflow and reduce heating performance.

Keep approximately 2 feet of clear space around the unit.

Carefully remove visible debris from the top and sides.

During colder mornings, auxiliary heat strips may turn on.

A brief burning-dust smell can happen when those strips operate after several months of inactivity.

Frost may also appear on the outdoor coil during cold and damp weather.

A small amount is generally normal if the defrost cycle clears it.

If the unit becomes heavily covered in ice and does not clear itself, professional inspection is recommended.

7. Check the Gas Supply and Furnace Ignition

A gas furnace needs a reliable gas supply and a working ignition system.

Homeowners can safely perform a few simple checks.

Make sure the gas valve serving the furnace is open.

Also confirm that the furnace power switch is turned on.

This switch often looks like a standard light switch and is usually located near the equipment.

Older furnaces with a standing pilot light should normally show a steady blue flame.

Anything beyond these basic checks should be handled by a professional.

A rotten-egg or sulfur-like smell is never normal.

If that odor is present, leave the home immediately.

Once everyone is outside and at a safe distance, contact the gas utility or call 911.

Do not light matches, operate electrical switches, or try to locate the source of the leak yourself.

8. Run a Test Cycle on a Mild Day

A mild October afternoon is a much better time to test the heating system than the first freezing night of winter.

Run the heat for approximately 15 to 20 minutes.

Pay attention to how the system starts, how the air feels at the vents, and whether the equipment shuts off normally.

Warm air should reach the rooms, and the system should complete the cycle once the thermostat reaches the set temperature.

Testing early gives homeowners time to arrange repairs while the house is still comfortable.

A faint burning-dust smell during the first heating cycle is often normal.

Dust may have settled on the heat exchanger or heat strips while the system was not in use.

When those components become hot, the dust burns away and can create a temporary odor.

The smell should usually fade within the first hour.

If the odor resembles melting plastic, hot electrical wiring, or continues for several hours, turn the system off and contact a qualified HVAC technician.

9. Listen for Unusual Sounds and Watch the Airflow

Some heating-system noise is normal.

A click at startup, the soft sound of burners igniting, and the steady hum of the blower are all expected.

Unusual sounds are different.

Loud banging during ignition, grinding, squealing, or repeated clicking without successful startup may point to a mechanical or ignition problem.

These issues usually become worse with continued operation.

Airflow can reveal problems as well.

Weak air from the vents, rooms that remain noticeably colder than others, or a system that turns on and off every few minutes may indicate a blower issue, duct problem, or failing component.

Take note of where the issue occurs and when it happens.

That information can help a technician diagnose the problem faster.

10. Schedule a Professional Heating Inspection

Basic homeowner checks are useful, but some important heating components are hidden behind access panels.

A professional inspection allows those parts to be checked safely.

The technician may inspect the heat exchanger for cracks, clean the flame sensor, check burners, test electrical connections and safety controls, and measure temperature rise through the system.

Heat pumps require additional inspection points.

These may include refrigerant performance, the reversing valve, defrost controls, and auxiliary heat strips.

Older gas furnaces deserve particular attention.

A cracked heat exchanger can allow combustion gases to enter the home's air supply.

TexAire Heating & Air Conditioning performs furnace and heat pump tune-ups across Lewisville that include inspection of important safety components before heating season.

Scheduling service in October gives homeowners time to complete any needed repairs before the first hard freeze.

Why Lewisville Residents Choose TexAire Heating & Air Conditioning

TexAire Heating & Air Conditioning is a family-owned HVAC company based on Briarcliff Road in Lewisville.

TexAire Heating & Air Conditioning provides furnace repair, heat pump service, air conditioning repair, system installations, and seasonal tune-ups for homes throughout the city.

Technicians service major equipment brands, including:

· Carrier
· Trane
· Lennox
· Goodman
· Rheem.

TexAire Heating & Air Conditioning focuses on finding the root cause of a heating or cooling problem and explaining findings clearly before any work begins.

Several things make TexAire Heating & Air Conditioning a practical choice for homeowners preparing for heating season:

· Experienced, licensed HVAC technicians who work on both furnaces and heat pumps
· Seasonal tune-ups that prepare the system for the switch from cooling to heating
· Safety-focused inspections of heat exchangers, burners, electrical controls, and other key components
· Clear repair explanations so homeowners know what needs attention before work begins
· Heating service for gas furnaces and all-electric heat pumps, depending on the home’s system

Many homeowners research local contractors before arranging service.

Lewisville residents often read customer feedback on the TexAire Heating & Air Conditioning page on Yelp and review the company's Better Business Bureau profile to learn about past service experiences.

TexAire Heating & Air Conditioning also shares seasonal maintenance reminders and service updates on its Facebook page.

Local Heating and Cooling Service Across Lewisville

TexAire Heating & Air Conditioning serves homes and businesses throughout Lewisville.

The service area includes long-established neighborhoods near Old Town as well as newer master-planned communities on the east side of the city.

Homes throughout Lewisville vary significantly in age and design.

Some were built during the 1970s and 1980s, while others are part of more recent construction.

That variety means technicians work with many different furnaces, heat pumps, ductwork layouts, thermostats, and HVAC configurations.

· Old Town Lewisville: TexAire Heating & Air Conditioning provides furnace inspections and heating repairs for older homes and storefronts around Main Street and Wayne Ferguson Plaza.

· Valley Ridge: Homes near Valley Ridge Boulevard and the Valley Ridge Greenbelt receive heat pump tune-ups and thermostat upgrades from TexAire Heating & Air Conditioning.

· Castle Hills: TexAire Heating & Air Conditioning supports larger multi-zone homes throughout Castle Hills with seasonal maintenance and heating system diagnostics.

· Vista Ridge: Residents near FM 3040 and the Vista Ridge shopping corridor rely on TexAire Heating & Air Conditioning for furnace repair and air conditioning service.

· Lewisville Valley: TexAire Heating & Air Conditioning handles heating and cooling replacements for established homes across the Lewisville Valley neighborhood.

· Indian Oaks: Families in Indian Oaks receive carbon monoxide safety checks and furnace tune-ups from TexAire Heating & Air Conditioning.

· Meadow Lake: Lakeside homes in Meadow Lake receive heat pump service and indoor air quality solutions from TexAire Heating & Air Conditioning.

· Briarhill Estates: TexAire Heating & Air Conditioning provides heating inspections and ductwork evaluations for homes throughout Briarhill Estates.

· Lake Park and Lewisville Lake: Properties near Lake Park Road and the Lewisville Lake shoreline receive year-round HVAC repair and maintenance from TexAire Heating & Air Conditioning.

Driving Directions to Reach TexAire Heating & Air Conditioning

TexAire Heating & Air Conditioning operates from 2018 Briarcliff Road on the south side of Lewisville, a short drive from Interstate 35E and the city's main east-west roads. 

The routes below show how to reach the TexAire Heating & Air Conditioning location from other well-known points around Lewisville.

Driving directions from Southern Comfort Mechanical Air Conditioning,

Heating & Plumbing to TexAire Heating & Air Conditioning

• Start at Southern Comfort Mechanical Air Conditioning, Heating & Plumbing on Lake Park Road in north Lewisville, TX.

• Head south from the Lewisville Lake area toward Interstate 35E using Lake Park Road and connecting local streets.

• Continue south on Interstate 35E through central Lewisville toward the south side of the city.

• Follow local roads to Briarcliff Road, where TexAire Heating & Air Conditioning provides furnace repair and heating tune-up services.

Driving directions from Koala-T Heating & Air to TexAire Heating & Air Conditioning

• Start at Koala-T Heating & Air on State Highway 121 in southeast Lewisville, TX.

• Drive northwest toward Interstate 35E using State Highway 121 and its connecting ramps.

• Continue north on Interstate 35E for a short stretch into south Lewisville.

• Turn onto local streets toward Briarcliff Road, where TexAire Heating & Air Conditioning offers heat pump service and HVAC maintenance.

Driving directions from Integrated Mechanical and Electric Services, LLC to TexAire Heating & Air Conditioning

• Start at Integrated Mechanical and Electric Services, LLC on East College Street near Old Town Lewisville, TX.

• Travel west from the Old Town area toward Interstate 35E using College Street and nearby connecting roads.

• Head south on Interstate 35E toward the southern part of Lewisville.

• Continue to Briarcliff Road, where TexAire Heating & Air Conditioning provides air conditioning repair and heating system inspections.

Wrapping Up;

October is a practical time to make sure the heating system is ready before winter weather arrives.

A few simple steps can prevent many common fall HVAC problems.

Replace a dirty filter, review thermostat settings, test smoke and carbon monoxide alarms, clear blocked vents, and run the system through a complete heating cycle.

Doing these checks while temperatures are still mild gives homeowners more time to handle any issues that appear.

Some warning signs require more caution.

A burning smell that does not fade, a gas odor, unusual sounds, or weak airflow may point to a problem that needs professional attention.

If any of these signs appear, leave the heating system off until it has been inspected.

With Lewisville's first frost risk increasing in late October and November, preparing early can help keep the home comfortable when the first major cold front arrives.

TexAire Heating & Air Conditioning helps Lewisville homeowners prepare furnaces and heat pumps for winter through seasonal tune-ups, safety inspections, and heating repairs.

Homeowners who want to learn more about the business before scheduling service can view the  TexAire Heating & Air Conditioning member listing with the Prosper Chamber of Commerce and the TexAire Heating & Air Conditioning business profile on Wheree, where service details and customer information are available.

FAQs

When should I switch from AC to heat in Lewisville, TX?

Most Lewisville homeowners start using heat in late October or early November when overnight temperatures regularly fall into the 50s or below.

Because afternoons may still be warm, some households may need heat in the morning and air conditioning later in the day.

Testing the heating system before the first strong cold front gives homeowners time to address problems before dependable heat becomes essential.

Is it normal for my heater to smell like burning the first time I turn it on?

A faint dusty or burning smell during the first heating cycle can be normal.

Dust may have settled on the heat exchanger or electric heat strips while the system was inactive.

When those components heat up, the dust burns away and may create a temporary odor.

The smell should usually fade within about an hour.

If it continues, resembles melting plastic or electrical wiring, or smells like rotten eggs, turn the heating system off and seek professional help.

How often should I change my air filter during the heating season in Lewisville?

Standard 1-inch filters generally need replacement every 1 to 3 months.

How often a filter should be changed depends on pets, household size, dust levels, and how frequently the HVAC system operates.

Lewisville homes that switch between heating and cooling throughout fall may need more frequent filter checks.

Thicker media filters generally last longer but still need routine inspection.

Should I leave my thermostat on Auto during October in Lewisville?

Auto mode allows the HVAC system to move between heating and cooling automatically.

During October, that can cause frequent mode changes because mornings may be cool while afternoons become much warmer.

Many homeowners prefer manually selecting Heat or Cool until outdoor temperatures become more stable.

Smart thermostats with a wider difference between heating and cooling settings can also help reduce unnecessary switching.

Does a heat pump need different checks than a gas furnace?

Yes.

A heat pump continues using the outdoor unit throughout heating season, so leaves, grass clippings, weeds, and other debris should be kept away from the condenser.

The thermostat should also be properly configured for heat pump operation so auxiliary heat strips do not run more often than necessary.

Gas furnaces require different safety checks, including working carbon monoxide alarms and professional inspection of the burners and heat exchanger.

What should I do if my carbon monoxide alarm goes off after turning on the heat?

Everyone should leave the home immediately and call 911 from outside.

Do not continue operating the heating system until a qualified technician has inspected the furnace, flue, and heat exchanger.

A blocked flue or cracked heat exchanger can be among the possible causes and must be professionally addressed before the system is used again.

When should I call an HVAC technician before switching to heat in Lewisville?

A professional inspection is worth considering if the system has not been serviced within the past year, the furnace is more than 10 to 15 years old, or the first heating test produces unusual odors, strange noises, weak airflow, or inconsistent operation.

TexAire Heating & Air Conditioning provides furnace and heat pump tune-ups throughout Lewisville that include checking important safety components before winter.

Scheduling service in October gives homeowners more time to complete repairs before demand increases after the first hard freeze.