AC Repair in Houston: Heat, Humidity and Hurricane Season

Houston air conditioners run hard for much of the year, so common failures are worn electrical parts, clogged condensate drains and refrigerant leaks. Humidity makes a properly sized system matter more than in drier cities. After a hurricane or flood, don't turn a flooded system back on until a pro has inspected it.

How hard does a Houston AC system work?

Very hard, for a long season. Based on NOAA's 1991–2020 climate normals for Houston's Bush Intercontinental Airport (NOAA climate normals, Houston Intercontinental):

• About 111 days a year reach 90°F or higher, and about 7 days reach 100°F.
• Annual precipitation averages 51.84 inches, so the air stays moist for much of the year.

NOAA's monthly normals show average highs of 94.5°F in July and 94.9°F in August, with average lows around 75°F in both months (NOAA monthly normals, Houston Intercontinental). The 90-degree days start in May and continue into October.

What that means for your system:

• Little rest at night. With overnight lows in the mid-70s, the system keeps running after dark.
• Lots of water to drain. In humid air, the indoor coil pulls out a steady stream of water that has to drain away.
• Parts wear faster. Capacitors, contactors and fan motors cycle many times through a long season.

Why does humidity matter so much for AC in Houston?

Because removing moisture is half of what your AC does here. ENERGY STAR explains that "in order for air conditioners to dehumidify or dry the air, they have to cycle long enough for moisture to condense on the coils and drain away" (ENERGY STAR).

That's why an oversized unit can be a problem in a humid city. ENERGY STAR says oversized air conditioners "short-cycle," and that "short operation times do not allow the system to effectively remove humidity with serious repercussions on both home comfort and durability." It also notes air conditioning accounts for over 20 percent of home energy expenses in hot, humid regions.

Signs your system may not be handling humidity well:

• The house feels cool but clammy.
• The system turns on and off often in short bursts.
• Condensation on windows or vents, or a musty smell.
• Mildew in closets or bathrooms.

If you're replacing a system, ask the contractor how they sized it. A room-by-room load calculation is a better basis than square footage alone. For a closer look at humidity problems in a similar climate, see our Tampa AC and humidity guide.

What are the most common AC repairs in Houston?

The same parts fail everywhere, but a long, humid season puts more hours on them. Common causes, roughly from simpler to more serious:

• Clogged condensate drain line. Algae and debris block the drain, water backs up, and some systems shut off or leak indoors. See AC leaking water inside.
• Failed capacitor. The outdoor unit hums but the fan won't start.
• Bad contactor. The switch that starts the outdoor unit wears out after many cycles.
• Dirty coils. Dirt on the indoor or outdoor coil cuts cooling and dehumidifying.
• Refrigerant leak. The system runs but blows warm or barely cool air.
• Condenser fan motor failure. The outdoor fan stops or runs slowly.
• Compressor problems. Less common, and usually the most expensive.

A pro will check these with meters and gauges. What you can safely check yourself:

• The thermostat is set to cool and the batteries are fresh.
• The air filter isn't clogged.
• The breakers for the indoor and outdoor units haven't tripped. Reset once only; if it trips again, leave it off and call a pro.
• The outdoor unit isn't blocked by plants, debris or storm litter.

If you smell burning, see smoke or sparks, turn the system off at the thermostat, leave the house and call 911 from outside. If water is pooling near the indoor unit or any electrical parts, stay clear of it.

What does AC repair cost?

These are national figures, not Houston prices, as of 2026:

• Diagnostic or service call: many contractors charge $75 to $250 (Fixr).
• Capacitor: $100 to $400 (Fixr).
• Contactor: often $150 to $400 to fix (Fixr).
• Clogged condensate line: $75 to $250 (Fixr).
• Drain pan: $200 to $600 (Fixr).
• Coil cleaning: $100 to $350 (Fixr).
• Refrigerant leak repair and refill: $200 to $1,500 (Fixr).
• Condenser fan motor: typically $200 to $700 (Fixr).
• Compressor: $600 to $3,000 (Fixr).
• Full AC replacement: most homeowners pay $5,000 to $12,000 (Fixr).

For a full breakdown, see our AC repair cost guide. If you're weighing a big repair on an older unit, our guide on whether to repair or replace your AC walks through the decision.

What happens to AC during Houston hurricanes and power outages?

Long outages in summer heat are the biggest risk. Hurricane Beryl made landfall in the early morning of July 8, 2024. The National Weather Service office for Houston/Galveston reported that high winds brought down numerous trees and power lines, causing widespread outages, and that heat indices of 100 to 106°F followed for several days, leading to heat advisories "due to millions without power" (NWS Houston/Galveston). CenterPoint Energy reported outages affecting more than 2.26 million customers at the peak (CenterPoint Energy).

The same NWS report lists two indirect deaths from carbon monoxide poisoning. If you use a generator:

• Never run it inside your home, basement or garage, or less than 20 feet from any window, door or vent (CDC).
• Use a battery-powered or battery backup carbon monoxide detector while it runs.
• Plan a cool place to go if the house gets too hot. The CDC suggests an air-conditioned shelter, a library or a mall, and warns not to rely on fans alone.

When power comes back, it's common for some systems not to restart. Check the thermostat and breakers first. If the outdoor unit hums without starting, or the breaker trips again, turn it off and call a pro.

What should you do if floodwater reached your AC?

Leave it off until a pro inspects it. Trane advises that if rising water flooded your outdoor unit or reached your furnace or air handler, "don't use your HVAC system until a heating and cooling specialist inspects it for damage" (Trane). Trane also says to turn the system off at the thermostat if floodwater approaches, and at the circuit breaker if water enters the home, but only if you can reach the panel without standing in water.

Flooding is a real risk here. The National Hurricane Center's report on Hurricane Harvey in 2017 notes "36 to 48 inches recorded in the Houston metro area" (National Hurricane Center).

What to expect after a flood:

• Replacement is often recommended. The Air-Conditioning, Heating, and Refrigeration Institute says "flood-damaged heating and cooling equipment and systems should be replaced and not repaired," and that the work should be done by qualified contractors, not homeowners (Air-Conditioning, Heating, and Refrigeration Institute). It adds that if a sealed system stayed intact, repair or replacement is a case-by-case call for a pro.
• Refrigerant lines can be damaged if floodwater shifts the indoor or outdoor unit even a little.
• Insurance may differ from what you expect. Trane notes that neither the equipment warranty nor standard homeowners insurance covers flood damage to an HVAC system, unless you have flood insurance.

Before hurricane season, ask a pro whether raising your outdoor unit on a secured platform makes sense. Trane notes this may involve wiring and refrigerant line changes, so it's not a do-it-yourself job.

How can you get your AC ready for hurricane season?

Hurricane season runs through the hottest months, so a little preparation in spring pays off. A simple checklist, drawn from the guidance above:

1. Schedule a tune-up before summer. Ask the technician to clean the coils, flush the condensate drain and test the capacitor and contactor, parts that wear with heavy use.
2. Know where your breakers are. Label the breakers for the indoor and outdoor units so you can switch them off quickly if water threatens, as Trane advises (Trane).
3. Clear the area around the outdoor unit. Trim plants and remove loose items that could become debris.
4. Ask about elevation if your yard floods. Raising the outdoor unit on a secured platform is a pro job.
5. Check your insurance. If flooding is a risk where you live, ask your agent whether you have flood coverage, since standard homeowners policies typically don't cover flood damage to HVAC equipment.
6. Plan for an outage. Test your carbon monoxide detectors, and if you own a generator, decide now where it will sit at least 20 feet from the house's windows, doors and vents (CDC).

After the storm passes, walk around the outdoor unit before turning the system on. If it was underwater, tipped or hit by debris, leave it off and call a pro.

Who can work on your AC in Texas?

Texas licenses AC contractors. The Texas Department of Licensing and Regulation says "contractors who install, repair, or maintain systems related to air conditioning, refrigeration, or heating" must have a license, and you can look up a license on its website (Texas Department of Licensing and Regulation).

Do you need a permit to replace an AC in Houston?

Yes. The City of Houston lists replacement of residential air conditioning among the work that needs a mechanical permit and inspection, and says it "requires a permit for the installation, repair, or replacement of condensing units" (Houston Permitting Center). Licensed contractors must register their state license with the city to buy permits. Ask your contractor to pull the permit and give you the number, and ask when the inspection will happen.

Many Houston-area suburbs and unincorporated parts of Harris County have their own rules, so confirm with your local office.

What should you ask an AC company?

1. Can you show me your Texas AC license number?
2. Is there a service call fee, and does it go toward the repair?
3. What did you find, and can you show me the failed part or the readings?
4. If refrigerant is low, where is the leak, and will you repair it or just recharge?
5. If you recommend replacement, how did you size the new system for humidity?
6. Will you pull the City of Houston permit?
7. What warranty covers the parts and the labor?

When should you call a pro?

Call when the system runs but doesn't cool, when the outdoor unit hums without starting, when water leaks indoors, or when the house stays humid. In peak summer heat, call sooner rather than later, especially if anyone in the home is older, very young or has health conditions.

Bellwick is a free service that helps you understand the likely problem and can connect you with a local heating and cooling company. Bellwick doesn't do the work. If you'd like a quick read first, check my heating & AC.