Why is my AC running but not cooling my Katy home?

The most common causes are a failed run capacitor, low refrigerant from a slow leak, or a frozen evaporator coil from restricted airflow. In Katy's heat, capacitors fail often because high temperatures degrade them. We check the capacitor and refrigerant charge first since those are the most common and least expensive, and we'll show you the reading before quoting anything.

How much does AC repair cost in Katy, TX in 2026?

Most Katy AC repairs run between $150 and $650. A capacitor is typically $150 to $350, a contactor $150 to $300, a refrigerant recharge with leak diagnosis $300 to $650, and a blower motor $300 to $600. Bigger jobs like a coil ($900 to $1,800) or compressor ($1,400 to $2,800) cost more. Our diagnostic is $85, waived when you approve the repair.

Should I repair or replace my AC in Katy?

Use the 5,000 Rule: repair cost times the unit's age. Under 5,000, repair it. Over 5,000, consider replacing. Replacement usually wins when a unit over 12 years old needs a compressor or coil, or when an old R-410A system has a leak, since R-410A now costs $75+/lb. We'll show you both numbers side by side so you decide, not us.

How do I know if my AC repair quote is fair, or if I'm being overcharged?

Ask to see the failed part and the meter reading, and get the quote in writing before work starts. Be wary of anyone who jumps straight to a $9,000 to $30,000 replacement on a system they haven't shown you is dead, or who wants to recharge refrigerant without finding the leak. A fair shop diagnoses, shows you the evidence, and prices the repair before touching anything.

What's the most common AC repair in Katy?

A failed run capacitor is the single most common repair, followed closely by contactors, which in Katy often fail because fire ants nest in them. Both are inexpensive and quick once diagnosed. Clogged condensate drains are the most common non-emergency call thanks to Katy's humidity.

Why does my AC work fine until it gets over 100 degrees F, then stop cooling?

That pattern usually points to a weak capacitor, a marginal compressor, or low refrigerant. The system can just barely keep up until peak heat demands more than it can deliver, then it gives out. It's a classic Katy mid-afternoon failure, and it's diagnosable. Don't wait for it to quit completely.

My AC stopped after a CenterPoint power surge. What should I check?

First check your breaker, then the thermostat, then the little float switch on the drain pan. Surges (Beryl reminded all of us) commonly take out the run capacitor or the control board. Those aren't safe to test on a live system, so if the breaker and thermostat look fine, call (713) 598-2737 and we'll find what the surge hit.

Do you repair AC in Cinco Ranch, Kelliwood, Firethorne, Elyson and other Katy neighborhoods?

Yes. We cover all of Katy, including Cinco Ranch, Kelliwood, Grand Lakes, Seven Meadows, Cross Creek Ranch, Firethorne, Tamarron, Elyson, Cane Island, and Old Katy, across ZIPs 77449, 77450, 77493, and 77494. We dispatch from the west side, so same-day service in Katy is routine, not a special trip.

Is 75 Degree AC licensed to work in Katy, and what warranty do repairs come with?

Yes. Our license is TACLA72152E, a Class A Texas air-conditioning license, verifiable at tdlr.texas.gov. Repairs come with a labor warranty on the work we perform, and replacement parts carry the manufacturer's warranty. We're fully insured, so your home and our crew are both covered.

Why does my Katy home still feel humid even when the AC is running?

Often the AC is oversized for the home, common in newer builder-grade Katy houses, so it cools fast but short-cycles before it pulls enough moisture out of the air. A clogged drain or weak airflow can do it too. We check sizing, drainage, and airflow together rather than just blaming the unit.

How fast can you get to Cinco Ranch or Seven Meadows on a 105-degree day?

Same-day in most cases. We stage near the Grand Parkway and I-10 interchange during summer peak, so the typical call-to-driveway time for 77494 and 77450 is a few hours, not a few days. Elyson, Anniston, and Aurora in 77493 are standard daily-route stops, not a special dispatch. Call before 3 PM for the best shot at today.

Do you offer financing for a full system replacement in Katy?

Yes, through multiple lenders. If a repair turns into a replacement conversation, we run the financing options during the estimate so you see your monthly payment alongside the system price before you decide. A 5-ton replacement doesn't have to be a cash-flow emergency.

AC Repair in Katy, TX: Same-Day Service

Looking for dependable HVAC services in Katy, TX? 75 Degree AC delivers expert air conditioning, heating, and indoor air quality solutions for homes and businesses, helping you stay comfortable in every season.

Call 75 Degree AC today

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Same-Day AC Repair in Katy, TX

Up-front pricing, an $85 diagnostic that’s waived when you approve the repair, and a licensed tech at your door the same day.

When your AC quits in a Katy summer, you don’t have hours to lose. We’re 75 Degree AC, and we run same-day AC repair across Katy, TX, including Cinco Ranch, Kelliwood, Firethorne, and Elyson (ZIPs 77449, 77450, 77493, and 77494). Service calls start at $85, waived with an approved repair. Our license, TACLA72152E, is a Class A Texas air-conditioning license, and you can verify it yourself at tdlr.texas.gov. Call (713) 598-2737 for same-day service.

We’ve been working Katy gate codes since 2016. We know the builder-grade systems in Cinco Ranch, the older units out toward Old Katy, and the brand-new equipment going into Elyson and Cane Island. When you call before 3 PM, you get a confirmed arrival window, not a vague promise that “someone will call you back.”

Fast AC Repair in Katy, TX: Cinco Ranch, Kelliwood, Elyson & Beyond

We dispatch from the west side of Houston, not from inside Loop 610, so reaching Katy isn’t a detour for us. It’s a normal Tuesday. That means a real arrival window instead of an all-day wait, and a tech who already knows the neighborhoods. We repair AC across all of Katy and the surrounding Grand Parkway corridor:

Cinco Ranch, Kelliwood, Grand Lakes, Seven Meadows (77450, 77494)
Cross Creek Ranch, Firethorne, Tamarron (77494, 77441)
Elyson, Cane Island, Old Katy (77493)
Mason Creek, Nottingham Country, and the 77449 corridor toward West Houston

If you’re inside Katy ISD boundaries, we cover you. Not sure if your street qualifies? Call (713) 598-2737 and we’ll tell you straight, before you book.

Our AC Repair Services in Katy

Same-Day AC Diagnosis & Repair

A licensed tech at your door the same day when you call before 3 PM. The $85 diagnostic is waived when you approve the repair, and you get the price in writing first.

Capacitor & Contactor Replacement

The #1 and #2 AC failures in Katy heat. Fire ants love outdoor contactors and short them out, so we replace both fast, usually on the first visit.

Refrigerant Leak Repair & Recharge

We find the leak first, then recharge. We never top off R-410A (now $75+/lb) without fixing why it's low, so you don't pay twice in three months.

Evaporator Coil & Compressor Repair

The bigger jobs. We show you the meter reading and the repair-vs-replace math side by side before you decide, no pressure toward a system you don't need.

Frozen Coil & Drain-Line Clearing

Ice on the coil and water around the air handler are Katy's most common calls. We clear the condensate drain, check the float switch, and fix the cause, not just the symptom.

24/7 Emergency AC Repair

A flat $85 diagnostic with no after-hours surcharge. A 95-degree house with a baby, an elderly parent, or pets is an emergency in our book, and we treat it like one.

AC Problems We Fix in Katy Homes

Most Katy service calls fall into one of eight buckets. Here’s what each usually means.

Our AC is running but not cooling

The unit hums, air moves, but the house won't drop below 80. Nine times out of ten in Katy that's a failed run capacitor, low refrigerant from a slow leak, or a frozen evaporator coil. We check the capacitor and refrigerant charge first because those are the cheapest and most common.

Our AC won't turn on at all

Dead thermostat, tripped breaker, a blown low-voltage fuse, or a failed contactor. In Katy we pull a lot of contactors that fire ants have nested in and shorted out. It's a real thing here, and it's an inexpensive fix once you find it.

Warm air is coming from the vents

Usually a refrigerant problem, a stuck contactor, or a failing compressor. We'll measure the refrigerant pressures and the temperature split before we tell you which.

Strange noises (grinding, squealing, clicking)

Grinding points to a motor bearing, squealing to a belt or blower motor, repeated clicking to a relay or a contactor that can't pull in. None of these get better on their own.

Water is leaking around the air handler

This is the single most common non-emergency call we get in Katy, and the reason is the humidity (more on that below). It's almost always a clogged condensate drain or a failed float switch.

The coil is frozen over with ice

Low refrigerant or restricted airflow (dirty filter, blocked return). We thaw it, find the cause, and fix the cause, because ice is a symptom, not the disease.

The house is cold but humid and clammy

Often an oversized builder unit short-cycling, or a drainage and airflow issue. We cover this in the FAQ because it's so common in newer Katy homes.

The unit short-cycles (turns on and off every few minutes)

Could be a refrigerant issue, an oversized system, a failing capacitor, or a dirty coil tricking the safety controls. We diagnose it rather than guess.

Same-Day & 24/7 Emergency AC Repair in Katy

When you call before 3 PM Monday through Saturday, we dispatch same-day with a confirmed arrival window at booking. For after-hours emergencies, the diagnostic is a flat $85 with no after-hours surcharge stacked on top. We’d rather earn your trust on the first call than nickel-and-dime you when you’re already miserable.

A 95-degree house with a baby, an elderly parent, or pets is an emergency in our book, and we treat it like one. Call (713) 598-2737 and tell whoever answers it’s an emergency.

Business hours: Monday to Friday 7 AM to 9 PM, Saturday 8 AM to 8 PM, Sunday 8 AM to 5 PM, plus 24/7 emergency dispatch for no-cooling and no-heat calls.

AC Repair Pricing in Katy, TX: What You'll Actually Pay

Most Katy AC repairs land between $150 and $650. Here's the honest breakdown so you walk in knowing the range before anyone touches your system. These are typical price ranges, not quotes. You'll get the exact number in writing before any work begins.

Repair	Typical Katy range	What's behind it
Run or start capacitor	$150–$350	The #1 failure. Houston heat cooks capacitors.
Contactor	$150–$300	Wear, or fire ants nesting in the contactor (a real Katy problem).
Refrigerant recharge with leak diagnosis	$300–$650	R-410A now runs $75+/lb. We never recharge without finding the leak.
Blower motor (ECM or PSC)	$300–$600	Weak airflow, warm air at the vents.
Evaporator coil	$900–$1,800	Corrosion or a refrigerant leak in the coil.
Compressor	$1,400–$2,800	The point where repair-vs-replace math kicks in.
Diagnostic fee	$85, waived with an approved repair	Up front. No stacking, no surprises.

Typical ranges, not quotes. You'll get the exact number in writing before any work begins.

If a tech ever wants to "top off your Freon" without diagnosing where it went, stop. Refrigerant doesn't get used up. If it's low, you have a leak, and recharging without fixing the leak means you'll be calling someone again in three to six months and paying twice.

Our Repair-First Promise: We Diagnose Before We Quote

Here’s the part most companies won’t put in writing. We show you the failed component before we quote anything. The bulged capacitor, the meter reading, the leak point we found with the detector. Then you get the price in writing, and you decide.

We don’t earn more on a $14,000 system than we do on a $300 capacitor, so we have no reason to push you toward a replacement you don’t need. When replacement genuinely is the smarter call, we’ll show you the math side by side and let you choose. That’s it.

What Happens When You Call

Step 1

You call (713) 598-2737. We confirm an arrival window on the spot, not "sometime today."

Step 2

We show up in the window and listen to what the system's been doing.

Step 3

We run the diagnostic with gauges and a meter, and we show you the reading.

Step 4

You get a written quote with the part, the labor, and the total, before we start.

Step 5

We make the repair and test the full system, temperature split and all.

Step 6

We clean up and tell you what to watch for so it doesn't happen again.

Repair or Replace? How to Decide for Your Katy AC

A good rule of thumb is the 5,000 Rule: multiply the repair cost by the age of the unit. If the number is under 5,000, repair it. Over 5,000, replacement starts to make sense. A $400 repair on a 6-year-old unit (2,400) is an easy fix. A $1,500 compressor on a 12-year-old unit (18,000) is a different conversation. Three things tip the math toward replacement in Katy:

Age over 12 years plus a major part (compressor or coil) failing.
Old R-410A systems with a leak. R-410A has climbed from $20–30/lb in 2020 to $75+/lb in 2026 under the EPA AIM Act. Recharging a leaky R-410A unit gets expensive fast. New equipment uses R-454B or R-32.
Rising bills. If a system is dragging your CenterPoint bill up every summer, a 16+ SEER2 unit pays part of its own way. Texas minimum is 14.3 SEER2; for Katy’s heat we recommend 16 or higher.

If replacement is the answer, we can handle that too. See AC installation. If it’s repairable, we’ll repair it.

Why AC Drain Lines Clog Faster in Katy Than Anywhere Else

Katy sees about 102 days a year above 90°F and runs at roughly 74.7% average annual humidity (NOAA, George Bush IAH normals 1991–2020). All that humidity becomes condensate that your AC has to drain. That’s why condensate drain lines here clog three to four times faster than they would in a dry climate, and why a clogged drain or a tripped float switch is our single most common non-emergency call in Katy.

The fix is cheap and the prevention is cheaper: one annual drain-line flush is the highest-return maintenance item a Katy homeowner can do. It heads off the water damage, the rusted-out drain pan, and the mid-July shutdown when the float switch finally trips.

Two more Katy-specific patterns worth knowing: fire ants love the warmth of an outdoor contactor and will short it out, and a CenterPoint power surge (we all remember Beryl) can take out a capacitor or a control board in an instant. Both are common, both are findable, and both are usually inexpensive once diagnosed.

Why Katy Homeowners Call 75 Degree AC First

Six reasons Katy homeowners call us first.

We're actually licensed, and you can check

TACLA72152E is a Class A Texas air-conditioning license, the unlimited tier. Verify it at tdlr.texas.gov. Plenty of competitors hold a lower Class B; we'll tell you the difference if you ask.

We show you the failed part before we quote

No mystery diagnosis, no surprise total.

We won't upsell you a system you don't need

Repair first, replacement only when the math says so.

We're local to Katy, not just "Houston-wide."

Working these gate codes since 2016, dispatched from the west side.

Fully insured

Your home and our crew are both covered.

Up-front pricing

$85 diagnostic, waived with the repair, quote in writing before work starts.

AC, Heating & Full-System Service for Katy Homes

Cooling Repair

Cooling is where Katy homes live or die from May through September. Houston humidity fouls evaporator coils faster here than almost anywhere, so we focus on coil condition, refrigerant integrity, and drainage, not guesswork.

Heating Repair

Katy winters are short but not harmless. A December cold snap pulls heat pumps out of defrost cycles they sat out for nine months and stresses gas furnaces on their first real run. We service both, gas and electric.

Full-System Replacement

An honest conversation. If your 14-year-old condenser's compressor is dying, the math usually favors a full swap once you factor SEER2 gains and financing. A 9-year-old Trane with a bad capacitor needs a $200 part, not a new system. We show you which it is.

Residential HVAC

Katy homes run big. Seven Meadows, Avalon, and Cinco Ranch floorplans routinely top 3,500 sq ft with two-story great rooms and west-facing glass that bakes all afternoon. We diagnose for that real load, not a rule of thumb.

Light Commercial HVAC

We service light commercial along Katy Mills Drive, the I-10 feeder, and Grand Parkway business parks: restaurants, dental offices, retail, and small offices that can't afford a day of downtime in July.

Maintenance & Tune-Ups

Twice-yearly service cuts breakdown risk by roughly 95 percent. Firethorne, Elyson, and Tamarron homes need their first real tune-up around year three; Cinco Ranch and Kelliwood need spring refrigerant-line and capacitor checks.

Brands & Models We Repair in Katy

We repair every major brand and most of the specific models going into Katy homes, including:

Carrier (Infinity 24ANB7, Performance series)
Trane (XV20i, XR16)
Lennox (SL28XCV, Elite series)
Goodman (GSXC18, GSX14)
Daikin (Fit, 19 Series)
Rheem, American Standard, Bryant, York, and the rest.

If it cools a Katy home, we can probably fix it. Builder-grade or high-efficiency variable-speed, we work on it.

Current Specials for Katy Homeowners

Available for residential and light-commercial AC repair across Katy, TX. Financing through multiple lenders is available on replacements, so a 5-ton system doesn’t have to be a cash-flow emergency.

Diagnostic Waived With Repair

The $85 service call comes off your invoice on any completed repair.

Free Estimate on New System Replacement

Clear, no-pressure estimates so you can plan a replacement confidently.

5% Senior Discount

Seniors get 5 percent off any qualifying repair in Katy.

AC Repair Across Katy, TX by ZIP Code

We cover all of Katy across four ZIP codes.

77449 (Northeast Katy)

Westfield, Raintree Village, Waterstone, Ventana Lakes, Bear Creek Village, Katy Mills corridor off I-10

77450 (Central/East Katy)

Southern Cinco Ranch, Kelliwood Gardens, Kelliwood Lakes, Kelliwood Courts, Memorial Parkway corridor

77493 (Northwest Katy)

Elyson, Anniston, Aurora, Camillo Lakes, Porter Ranch, FM529 / Katy-Hockley build zones

77494 (Southwest Katy)

Western Cinco Ranch, Firethorne, Seven Meadows, Avalon, Tamarron, Falcon Landing, Katy Ranch Estates, Seven Lakes

Areas We Serve Across Greater Houston

75 Degree AC proudly provides HVAC services to homeowners and businesses throughout Houston and nearby communities, including:

Houston

Richmond

Katy

Cypress

Sugar Land

Stafford

Missouri City

Pearland

Tomball

Rosenberg

Fulshear

Bellaire

If your location is not listed, contact our team to confirm service availability in your area.

Contact Our Team

What Katy Homeowners Say

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24/7 dispatch for no-cool emergencies.

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Serving Richmond and the Grand Parkway too.

Get Same-Day AC Repair in Katy: Call (713) 598-2737

Don’t sweat it out. We’ll get a licensed tech to your Katy home today, show you what’s wrong, and quote it in writing before we start. Call (713) 598-2737 or request service online for a confirmed arrival window.