Four squares, one comfortable home
Everything that keeps your house comfortable.
Look closely at our logo: a snowflake, a fan, a flame and a thermometer. That’s the whole job: cooling, airflow, heating and the controls that tie them together.
Cooling
Air conditioning repair, replacement and the upstairs bedroom that never cools off.
Airflow
Ducts, returns, filters and blowers: the half of comfort nobody sees.
Heating
Gas furnaces, heat pumps and auxiliary heat that’s ready for the first blue norther.
Controls
Thermostats set up right, and tune-ups that catch problems before July does.
What “in your corner” means
Honesty. Integrity. Quality.
Honesty
We tell you what’s wrong in plain words, what it costs, and whether it’s worth fixing. If a repair will carry you another five summers, we’ll say so.
Integrity
Licensed, permitted and done to code, whether anyone’s watching or not. The work behind the panel gets the same care as the work you can see.
Quality
Clean installs, tidy job sites and a walk-through before we leave, so you know exactly what was done and how your system works.
Tommy from 4Square did an amazing job! He fixed our outdoor contactor coil the exact same day we called. He was incredibly courteous, professional, and had everything running smoothly in no time. Highly recommend 4Square Heat & Air for fast, reliable local service!
Angi · 5.0 · Central A/C installation
What one homeowner said about Tommy and his crew:
- Handled the install professionally
- Excellent pricing
- Showed up and finished on time
- Cleaned up nicely
- Walked us through the final installation check
Nextdoor neighbors
“He replaced our ac unit, recently.”S. L., Murphy, TX
Neighborhood Favorite in 2022 and 2023, recommended by neighbors in Murphy and Frisco as “honest, reliable” with “great service.”
Local knowledge
Built for 105° Augusts and February freezes.
Collin County asks a lot of a heating and air system: months of triple-digit afternoons, attics hotter than an oven, two-story homes with a stubborn upstairs, construction dust and cedar pollen, and the occasional hard freeze that tests every furnace and heat pump at once.
We size, repair and set up systems for that reality, not for a brochure.
- Attic air handlersDrain pans, float switches and duct runs that live in 140° heat.
- Two-story homesBalancing airflow so upstairs bedrooms keep up.
- Dust & pollenFiltration that cleans the air without choking the system.
- Freeze-ready heatFurnaces, heat pumps and aux heat checked before the cold.
How it works
Four steps. No runaround.
Call (469) 556-0507 or send a request online. You’ll talk to someone who knows HVAC, not a call center.
(469) 556-0507Call or send a request
Tell us what the system is doing (or not doing), and where you are.
We diagnose it
We find the actual cause and explain it in plain language.
You choose
Clear options and a price before any work begins.
We fix it right
Clean work, a final check with you, and a system that runs like it should.
Service area
Collin County, square by square.
- McKinney
- Princeton
- Lowry Crossing
- New Hope
- Farmersville
- Lavon
- Nevada
- Josephine
- Blue Ridge
- Wylie
- Melissa
- Anna
- Fairview
- Lucas
- Allen
- Prosper
Straight answers
HVAC questions, answered.
Why is my AC running but blowing warm air?
The most common causes are a failed capacitor or contactor at the outdoor unit, a tripped breaker, a frozen indoor coil, or low refrigerant from a leak. Check that the thermostat is set to Cool, the filter is clean, and the outdoor unit’s fan is spinning.
Why does my furnace smell like burning when I first turn it on?
A dusty, burning smell for the first few minutes of the season is normal: dust that settled on the heat exchanger over the summer is burning off. It should fade within an hour.
How long does an AC system last in North Texas?
Around 10–15 years is typical here. Long, hot cooling seasons put more hours on a system than in milder climates. Gas furnaces often last longer, 15–20 years, because they run fewer hours.
How often should I change my air filter?
Check it monthly and replace standard 1-inch filters every 1–3 months. Change them more often in peak summer, during construction dust or pollen season, or with pets. Thicker 4–5 inch media filters often last 6–12 months.
How do I check an HVAC contractor’s license in Texas?
Use the Texas Department of Licensing and Regulation (TDLR) license search and look for an Air Conditioning and Refrigeration Contractor license. TDLR licenses and regulates HVAC contractors in Texas.
