Richardson, TX Troubleshooting Guide

AC Stopped Working in Richardson, TX? What to Check and When to Call a Pro

Most Richardson AC shutdowns trace back to a tripped breaker, a tripped condensate float switch, or a failed capacitor. Check six things yourself first, then call a licensed tech for anything electrical or refrigerant related.

Written by the Richardson TX HVAC Hub team | Last updated: September 30, 2026 | 8 min read

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Quick Answer

Key Takeaways

When an AC stops working in Richardson, the most common causes are a tripped breaker, a tripped float switch from a clogged condensate line, a failed capacitor or contactor, a dirty filter causing a coil freeze, or a thermostat problem.
Homeowners can safely check 6 things before calling: thermostat settings, the breaker, the air filter, the condensate float switch, the outdoor disconnect, and whether Oncor is reporting an outage.
Refrigerant, capacitor, compressor, and wiring work should go to a licensed technician. Texas requires an ACR license from TDLR, and the City of Richardson requires HVAC contractors to register with Building Inspection.
Many Richardson homes have air handlers in the attic, so a stopped AC often starts as a clogged drain line that shuts the system off to protect the ceiling below.
During an NWS Fort Worth heat advisory, a home without cooling can become unsafe within hours for infants, older adults, and pets. Treat no-cooling in extreme heat as an emergency.
In a review of 16 negative North Texas HVAC reviews (pulled September 30, 2026), half described a $5,500 to $34,000 replacement quote that a second opinion fixed for $34 to $450.

The Basics

What “AC Stopped Working” Usually Means

An AC that stopped working is a system that either will not start, runs without producing cold air, or shuts itself off shortly after starting. Each symptom points to a different set of causes.

Won’t turn on at all: power, breaker, thermostat, float switch, or safety switch issue.
Runs but blows warm air: capacitor, contactor, refrigerant, compressor, or outdoor fan issue.
Turns on, then shuts off (short cycling): airflow restriction, frozen coil, oversized system, or failing thermostat.
Stopped after water showed up: clogged condensate drain and tripped float switch.

Before You Call

6 Things to Check Before Calling for AC Repair in Richardson

A Richardson homeowner can check these six items safely without opening any electrical panel on the equipment.

Thermostat. Confirm it is set to “Cool,” the set point is below room temperature, and the batteries work. Smart thermostats can lose Wi-Fi or schedule settings after a power blip.
Breaker panel. Look for a tripped breaker labeled AC, condenser, or air handler. Reset it once. If it trips again, stop and call a technician. A repeat trip signals an electrical fault.
Air filter. A clogged filter restricts airflow and can freeze the indoor coil. Replace it. If the coil is iced, set the system to “Off” and the fan to “On” to thaw before running cooling again.
Condensate float switch. Check the attic or closet air handler for a small switch on the drain pan or drain line. If the pan holds water, the float switch has likely shut the system down. The drain line needs to be cleared.
Outdoor disconnect. The gray box on the wall near the outdoor unit should be in the “On” position. Landscapers and pressure washers sometimes knock it off.
Oncor outage status. Oncor delivers electricity to Richardson. Check the Oncor outage map or text alerts. Brownouts and voltage dips during peak demand can trip safety controls or damage capacitors.

Common Causes

Common Reasons an AC Stops Working in Richardson Homes

The table below matches the symptom Richardson homeowners report to the most likely cause and whether the fix is DIY or a job for a licensed tech.

Symptom	Likely Cause	DIY or Pro?	Why It Happens in Richardson
No power, nothing runs	Tripped breaker, float switch, blown fuse at disconnect	Breaker and float check: DIY. Repeat trips: Pro	High load days during long cooling season
Outdoor unit hums, fan not spinning	Failed capacitor	Pro	Heat stress on capacitors in summer
Indoor fan runs, air is warm	Capacitor, contactor, low refrigerant, compressor	Pro	Systems run near full capacity for months
Ice on lines or indoor coil	Dirty filter, weak blower, low refrigerant	Filter: DIY. Refrigerant: Pro (EPA and TDLR rules)	Long runtimes plus restricted airflow
Water in attic pan or ceiling stain	Clogged condensate drain	Pro for clearing and pan inspection	Attic air handlers in many Richardson homes
Squealing or grinding, then shutdown	Motor bearing or blower failure	Pro	Worn motors fail under heavy summer use

What These Repairs Typically Cost (2026)

Repair	Typical Range	Source
Capacitor replacement (single run)	$95 to $300	PickHVAC, 2026 national data
Dual/triple capacitor assembly	$140 to $600	PickHVAC, 2026 national data
Most common AC repairs	$150 to $650 (avg. about $350)	Fixr, July 2026 national data
Major repairs (compressor, coil)	$2,000 to $3,500+	Fixr, July 2026 national data
After-hours or emergency service	Add $150 to $300+	2026 national cost guides

Figures are national averages checked September 30, 2026. Richardson prices can vary; get at least two written quotes.

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Heat Safety

When a Stopped AC Is an Emergency in Richardson

A stopped AC is an emergency when indoor temperatures are rising during an NWS Fort Worth heat advisory or excessive heat warning, or when anyone at risk lives in the home.

Infants, older adults, and people with medical conditions are most at risk from indoor heat.
Pets left in a home without cooling can overheat quickly.
The Richardson Fire Department and City of Richardson publish heat safety guidance. If someone shows signs of heat illness, call 911 first, then the HVAC company.

Richardson Cooling Resources

If repair will take hours, move vulnerable people to a cooled space. The City of Richardson lists these cooling resources (checked September 30, 2026):

Richardson Police Department lobby, 140 N Greenville Ave: opened as needed during widespread outages. Call the non-emergency line, 972-744-4800, for hours.
Richardson Public Library, 2360 Campbell Creek Blvd., Suite 500.
Heights Recreation Center, 711 W. Arapaho Rd., 6 a.m. to 10 p.m.
Huffhines Recreation Center, 200 N. Plano Rd., 6 a.m. to 10 p.m.
Dallas County Health and Human Services offers emergency window AC units to qualifying low-income households: 214-819-1976.
Call 2-1-1 for current relief center openings.

Local Insight

Why Richardson Attic Units Cause So Many Shutdowns

Many Richardson homes, most built between the 1970s and 1980s, have the air handler in the attic, which makes the condensate drain the most common silent cause of a stopped AC.

Measure	Median Year Built	Typical Age in 2026	Source
All Richardson housing	1986	About 40 years	Point2Homes Richardson Demographics
Dallas County side properties	1973	About 53 years	TopHap

The citywide figure likely includes newer apartments and the Collin County side, which pulls the median later than older single-family neighborhoods.

Condensate drains clog with algae and debris over a cooling season.
A float switch or secondary pan protects the ceiling by shutting the system off. The AC looks “broken,” but the safety device did its job.
Richardson adopted the 2021 International Codes, including the 2021 International Mechanical Code and 2021 International Residential Code, with North Texas regional amendments, effective April 24, 2023.
Condensate disposal: 2021 IMC Section 307.2 (IRC M1411.3 for homes) requires condensate to drain to an approved location.
Secondary drain protection: IMC 307.2.3 (IRC M1411.3.1) requires a secondary drain pan, auxiliary drain, or water-level shutoff switch where overflow could damage the building. This is the float switch that shuts a Richardson attic AC off.
Attic access: IMC 306.3 (IRC M1305.1.3) requires a clear passageway and solid walkway to attic equipment, plus a light and receptacle near the unit (IMC 306.3.1).
Tight attic access and missing walkways can add time to a repair. A tech should tell you this before starting work.

Decision Guide

Repair vs. Replace When an AC Stops Working

Repair is usually the better choice when the failure is a single part such as a capacitor, contactor, float switch, or drain line. Replacement enters the conversation when the compressor fails on an older system or when repairs keep repeating.

Lean repair: system under 10 to 12 years old, first major failure, parts under warranty.
Lean replace: compressor failure out of warranty, system uses R-22 refrigerant, repeated breakdowns in one season, rising Oncor bills.
Replacement in Richardson requires a mechanical permit through City of Richardson Building Inspection. The contractor should pull it.

Hiring

How to Verify a Richardson AC Contractor

A legitimate Richardson AC contractor holds a Texas ACR license from TDLR and is registered with the City of Richardson.

Search the license number on the TDLR license search.
Check the City of Richardson Registered Contractors List.
Ask whether the repair or replacement requires a permit. Most simple repairs do not. Equipment replacement does.
Get the diagnosis in writing before approving major parts like a compressor or coil.

Review Analysis

What Richardson HVAC Companies Don’t Tell You

The most common complaint in negative HVAC reviews is not slow service. It is a replacement quote for a problem that turned out to be a cheap part.

Our review sample: 16 negative Google reviews of North Texas HVAC companies, pulled September 30, 2026. Reviews were posted between roughly 2022 and 2026. Company names are withheld.

Complaint Pattern	Reviews	What Happened
Replacement pushed when a small repair fixed it	8 of 16 (50%)	Quotes of $5,500 to $34,000; second opinions fixed the problem for $34 to $450
Maintenance plan billed but service missing or extra	3 of 16	Autopay kept charging with no visits; drain line clearing added at $350
Refrigerant added without finding the leak	1 of 16	$535 for refrigerant, then a $250 leak search a week later
Missed appointments or slow return visits	3 of 16	No-shows and multi-day waits during summer heat

Real examples from the sample

$5,500 condenser quote vs. $34 capacitor. A tech read “bad” on a meter and quoted a new condenser. The condenser fan was not spinning, a classic failed capacitor sign. A second tech replaced the capacitor for $34 the same afternoon.
$9,850 system quote vs. a loose wire. A homeowner was told the compressor was dead and given three replacement options. The second company found a loose wire.
$7,600 repair claim vs. $450 fix. A home warranty technician quoted coils and a condenser. An independent company replaced a failed fan motor for $450.
$5,000 in ductwork and plenum work vs. a $100 wire. After years of capacitor swaps that did not help, an independent tech found a rodent had chewed the low-voltage wire to the contactor.
Refrigerant before diagnosis. One homeowner paid $535 for about 4 lbs of refrigerant without the leak being located. The AC stopped cooling within a week, and a later leak search found a failed evaporator coil.

What this means when your AC stops working

Ask what failed and why. A real diagnosis names a part and a test result, not “it’s old.”
Get a second opinion on any quote over $2,000. In half of this sample, the second opinion was a small repair.
Don’t pay for refrigerant until the leak is found. Adding refrigerant to a leaking system is a temporary fix. Ask for the leak location in writing.
Check the fan before accepting a condenser or compressor quote. If the outdoor fan is not spinning, ask whether the capacitor was tested.
Read the maintenance plan. Confirm drain line clearing is included, and track the visits you are billed for.
Be cautious with home warranty dispatches. 3 of the 8 upsell cases came through home warranty referrals, where the covered amount was a small share of the quote.

FAQ

Frequently Asked Questions

Why did my AC just stop working in the middle of the day?

An AC that stops mid-day in Richardson usually tripped a breaker, tripped its condensate float switch, or lost a capacitor under peak heat load. Check the breaker and the attic drain pan first.

Can I reset my AC myself?

Yes, you can reset the breaker once and turn the thermostat off for 5 minutes, then back on. If the breaker trips again or the unit hums without starting, call a licensed technician.

Why is my AC running but not cooling?

An AC that runs without cooling often has a failed capacitor, a bad contactor, a frozen coil, or low refrigerant. Only a TDLR-licensed tech with EPA certification can test and handle refrigerant.

My AC stopped and there’s water in the attic pan. Is that bad?

Water in the pan means the condensate drain is clogged and the float switch shut the system off to protect your ceiling. Turn the system off and have the drain line cleared before the pan overflows.

Does an Oncor outage affect my AC after power comes back?

Yes, it can. Power surges and voltage dips can damage capacitors, contactors, and control boards. If the AC does not restart after Oncor restores power, reset the breaker once, then call for service.

Do I need a permit to fix my AC in Richardson?

Most repairs, such as replacing a capacitor or clearing a drain, do not need a permit. Replacing the AC or furnace does require a mechanical permit from City of Richardson Building Inspection, and adding central AC or a mini-split needs mechanical and electrical permits. Third-party permit trackers estimate Richardson residential mechanical permit fees at roughly $70 to $225.

How fast can someone fix my AC in Richardson?

Many Richardson-area HVAC companies offer same-day service in summer, but wait times climb during heat waves. If the unit stops during an NWS Fort Worth heat advisory, call more than one company and use a city cooling resource while you wait.

Sources

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Richardson TX HVAC Hub connects homeowners with licensed local contractors for AC repair. Ask for a written diagnosis that names the failed part before approving any major repair or replacement.

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