If you need AC repair in Lewisville, TX, the details that matter most are a bit unusual for DFW: two different electric wires companies, a city rule about rental homes, and a large neighborhood that only recently joined the city. Here is what is specific to cooling and heating a Lewisville home, and what to expect when you call.
The number (469) 649-7066 is a free referral line run by Dallas Air & Heating. It does not employ technicians. An automated assistant picks up at any hour, asks if the problem is heating or cooling, and writes down who you are, how to reach you, your ZIP and the symptoms. Next, your call goes through to a locally owned, independent HVAC business working in Lewisville, which hears a short summary first. You arrange the visit and the price with that company directly.
Lewisville: a farm town the lake turned into a suburb
According to the Handbook of Texas, Lewisville began as Hallford Prairie, took the name of Basdeal W. Lewis after he bought the land in 1853, and built the first cotton gin in Denton County in 1867. It stayed small for a long time: about 1,500 residents in 1950. Federal engineers started impounding Lewisville Lake on the Elm Fork of the Trinity River in November 1954 and finished the project in 1955. With the lake, Interstate 35E and later DFW Airport, the town took off, reaching 24,273 people in 1980, 77,737 in 2000 and 111,822 in 2020.
The lake still shapes the city. The Texas Water Development Board lists its conservation pool at 27,175 acres and describes it mainly as a water supply for Dallas, Denton and nearby communities, and Wikipedia notes that about 6.2 of the city's 43.2 square miles are water. That steady climb means Lewisville has houses from every decade since the 1960s, plus a large share of apartments. The Census Bureau puts the owner-occupied rate at 46.3 percent, so more than half of homes are rented. When the AC fails in a rental, who calls whom matters, and the city has a clear rule about it, covered below.
Oncor or TNMP? Sorting out power in Lewisville
Lewisville is served by more than one transmission and distribution utility. Texas-New Mexico Power, known as TNMP, is headquartered here and serves much of the city, and some addresses are on Oncor's lines instead. Your wires company is printed on your bill. You still choose your own retail provider either way.
The house is dark
That is an outage. Report it to the wires company on your bill: TNMP at 888-866-7456, or Oncor. Turn the thermostat to Off until the power is back and steady.
Lights on, AC off
Make sure the thermostat says Cool and has fresh batteries. A tripped breaker can be reset once; a second trip means stop and get an HVAC company out.
Running but warm
Replace a dirty filter and clear grass or debris from around the outdoor unit. Ice on the lines or a fan that does not spin means shut it off and call.
The city's HVAC rules, including for rentals
The City of Lewisville's Building Services Division publishes a residential HVAC handout, updated January 1, 2024. It says a permit is required for all HVAC installations, which must meet the International Residential Code, the International Mechanical Code and local ordinances. Applications are filed online and fees are paid before the permit is issued.
The handout spells out who may do the work. A homeowner may work on his or her own primary residence under state law, but anyone else must be a licensed mechanical contractor registered with the city. Recovering refrigerant always takes a licensed HVAC contractor. And on rental property, the city says all work must be done by a licensed HVAC contractor, with no exceptions.
- If you rent: report the problem to your landlord or manager in writing and keep a copy. Your lease normally says how repair requests must be made and who arranges the work.
- If you own a rental: a licensed contractor is required for the work, and the permit is part of the job. Ask for both on the quote.
- If you own your home: let the contractor pull the permit and schedule the inspection, and keep the record for when you sell.
Castle Hills joined the city in 2021
Castle Hills, northeast of the original city, was a large development outside Lewisville's limits for years. The city completed its annexation on November 15, 2021, adding almost 3,000 acres and about 18,000 residents. That is part of why the Census Bureau's estimate for Lewisville jumped to 139,006 by July 2025.
For Castle Hills homeowners, annexation means the City of Lewisville's permit and inspection process now applies to HVAC replacements. The city's own annexation page also points out two local details: street lighting there is provided by CoServ, and the Castle Hills HOA handles architectural review through its own committee. If a new system means a larger condenser or a new spot for it, check with the HOA first.
Gas heat and safety in Lewisville
Atmos Energy's Mid-Tex Division supplies natural gas in Lewisville; the city council considered its latest rate settlement with Atmos in September 2026. Many Lewisville homes have a gas furnace in the attic or a hall closet paired with an outdoor AC unit, while others use an electric heat pump. When you call, say which you have, because that helps the company you are connected with send someone ready for it.
Smell gas? Get out of the house first, then call 911 or Atmos Energy at 866-322-8667 from outside. Call the line about the furnace only after the gas company has cleared the house.
Why Lewisville homeowners call the line
Landlords and owners of rentals
With more than half of Lewisville homes rented, many callers are owners who need an independent company for a tenant's unit. You give the property's ZIP code and the line routes the call to a company that serves it.
Castle Hills and new city rules
Homeowners new to Lewisville's permit process can ask the company they reach to handle the city permit and inspection, and confirm that in the written quote.
A clear first step on mixed utilities
Whether your wires are Oncor or TNMP, the AC itself is an HVAC job. One free call, any hour, and you are put through to an independent local company instead of searching at midnight.
A license you can look up
Lewisville requires licensed contractors for anyone but a homeowner on their own home. This page links the TDLR license search so you can check the number on any quote.
Services Lewisville homes need most
From May to September most calls are for AC repair: warm air, a tripped breaker, or water from an attic drain pan. If the system quits after hours, emergency AC repair covers what to do while you wait. Owners of several units, or of rental homes, often book a spring HVAC tune-up to catch a weak part before a tenant's July call. For gas furnaces and heat pumps, see furnace and heating repair.
AC Repair
Warm air from the vents, a unit that hums but will not start, ice on the lines or water in the ceiling. What a proper diagnosis covers in Dallas heat and what to ask before you approve a repair.
Emergency AC Repair (24/7)
No cooling at night, on a weekend or in a heat wave. What to do while you wait, who is most at risk, and how after-hours calls are usually priced.
Furnace and Heating Repair
No heat on a cold North Texas morning, a furnace that short cycles or a heat pump stuck in defrost. Gas safety first, then what a technician checks.
HVAC Tune-Up and Maintenance
What a real spring or fall tune-up includes, what it does not, and the simple filter and drain habits that keep a system out of trouble.
How a Lewisville call works
- Call any hourAn automated assistant answers (469) 649-7066 and asks whether it is about cooling or heating.
- Describe the problemGive your name, a callback number, your city or ZIP and what the system is doing.
- Get put throughThe call goes to an independent, locally owned heating and air conditioning company, which hears a short summary before it picks up.
- Deal with them directlyThat company diagnoses, quotes, does the work and is paid by you. If it cannot answer, it gets your details to call back.
How this line works: Dallas Air & Heating is a free phone line, not an HVAC company. It answers your call and connects you with an independent local heating and air conditioning company, which inspects, quotes and does the work, and which you pay directly. The line holds no HVAC license and does not repair, install or schedule anything itself. Those companies may pay Dallas Air & Heating a referral fee. You never pay the line. How it works.
Check the license yourself. In Texas, air conditioning and refrigeration contractors are licensed by the Texas Department of Licensing and Regulation (TDLR), and the license number belongs on the company's quotes and invoices. Ask for it and look it up with the TDLR license search (opens in a new tab) before work starts. It is also fair to ask for a certificate of insurance.
Areas near Lewisville
More cities in the metroplex with their own page: