Air conditioning repair in Houston goes better when you know what the parts of your system do. Central air here has two jobs, cooling the house and drying it, and the parts that do those jobs wear out in fairly predictable ways. This guide walks through each component, what failure looks like, and what the repair actually involves, so the technician's explanation makes sense and the price can be weighed.
Houston Air & Heating does none of this work itself. It is a free phone line: an automated assistant asks about the problem, then passes your call to an independent, locally owned HVAC business in the Houston area, which diagnoses, quotes and repairs and is paid by you.
How central air works in Gulf Coast humidity
A split system has an outdoor unit (the condenser, with the compressor and a large fan) and an indoor unit (the air handler or furnace, with a blower and the evaporator coil). Refrigerant flowing between them picks up heat from your indoor air at the cold coil and releases it outside.
In Houston, the cold coil does something just as important: it wrings water out of the air. Moisture condenses on the coil, drips into a pan and leaves through the condensate drain. That only works when the system runs long enough. ENERGY STAR warns that an oversized unit short cycles, so less moisture drains off the coil and the air is left damp, and Department of Energy research notes that correct sizing is especially important in humid climates.
So a Houston system can fail in two ways: it can stop cooling, or it can keep cooling while losing its grip on humidity. Sticky air at a normal temperature, musty smells and sweating supply vents are worth mentioning on the call, because they point the technician toward airflow, coil and sizing questions rather than a broken part.
Air conditioner components: what wears out and what the repair involves
Each row is a part a technician may name on your invoice. The repair column describes the job in general terms; the right fix for your system comes from testing it.
| Component | What it does | How failure shows up | What the repair involves |
|---|---|---|---|
| Capacitor | Stores a charge that helps the compressor and fan motors start and run | Outdoor unit hums, fan will not spin or needs a push | Tested against its rating and replaced; usually a quick swap if the part is on hand |
| Contactor | Switch that sends power to the outdoor unit when the thermostat calls | Outdoor unit will not start, or will not shut off | Pitted or stuck contacts replaced; wiring checked for heat damage |
| Condenser fan motor | Pushes heat away from the outdoor coil | Fan slow, noisy or stopped while the compressor runs hot | Motor and often its capacitor replaced; blade checked for balance |
| Blower motor | Moves house air across the indoor coil and through the ducts | Weak airflow at every vent, iced coil, no air at all | Motor or control module replaced; blower wheel cleaned |
| Evaporator coil | The cold indoor coil that absorbs heat and condenses moisture | Slow loss of cooling, ice, a low charge that keeps coming back | Leak located and repaired if practical, otherwise coil replaced, then system evacuated and charged |
| Compressor | Pumps refrigerant through the whole system | Breaker trips, loud start, outdoor fan runs but no cooling | Electrical tests first; a failed compressor is the largest repair and often triggers a replace discussion |
| Metering device | Controls how much refrigerant enters the indoor coil | Poor cooling with odd pressure readings, frosting in one spot | Valve or orifice replaced; refrigerant recovered and recharged |
| Condensate drain and float switch | Carries coil water outside; the switch shuts the system off if water backs up | System stops cold, water in the pan, ceiling stain | Line cleared and flushed, pan inspected, switch tested |
| Thermostat | Tells the system when to run | Blank screen, wrong readings, system ignores settings | Batteries, wiring and placement checked; unit replaced if faulty |
| Attic ductwork | Carries cooled air to rooms and brings room air back | One room hot, dusty vents, a hot attic smell | Torn or disconnected flex duct repaired and sealed |
The parts Houston heat is hardest on
The Department of Energy lists frequent on and off cycling as a cause of electrical control failure, and names refrigerant leaks, skipped maintenance such as dirty filters, and drainage problems among the most common air conditioner troubles. Here those stresses stack up. A cooling season that runs from spring into fall means heavy cycling for months, and a coil that sheds water every day keeps the drain line and pan busy.
Electrical starting and switching parts
Capacitors and contactors sit inside a metal cabinet in direct sun. They are small, inexpensive parts relative to the system, which is why a correct diagnosis matters: replacing one is a modest job, but only if it is truly the part that failed. These are not homeowner repairs. A capacitor can hold a dangerous charge even with the power off.
Water handling
Algae and sludge build up in condensate lines over a long, wet season. When the main line clogs, a float switch may shut the system down to protect the ceiling, which can look like a total breakdown. Clearing the line and testing the switch is usually a short visit.
Attic equipment and ducts
Many Houston homes have the air handler and most of the ductwork in the attic. Leaky ducts, and return air pulled in from a hot attic, add heat and humidity the system then has to remove. A disconnected or crushed flex duct shows up as one room that never cools, and a technician can usually find it with a flashlight and a temperature reading at each vent.
Ask whether the duct repair includes sealing the joints with mastic or tape rated for the job, not just reattaching them.
Refrigerant rules that shape your repair options
Refrigerant work is the part of air conditioning repair where federal rules matter most, and they affect what a fair quote looks like.
- Only certified technicians open the system.Federal Clean Air Act rules (Section 608) say anyone who attaches gauges, adds or removes refrigerant, or replaces a sealed system part must hold EPA Section 608 certification, and only certified technicians may buy refrigerant for home systems. Knowingly venting refrigerant is illegal.
- Low refrigerant means a leak.Refrigerant is not used up like fuel. The EPA advises homeowners to have leaks found and repaired rather than paying to top off a leaking system again and again.
- R-22 is in its final chapter.U.S. production and import of new R-22 ended on January 1, 2020. Existing R-22 systems can still be serviced with recovered and reclaimed refrigerant, but the EPA expects that supply to keep getting more expensive.
- R-410A systems can still be repaired.EPA rules under the AIM Act cap new residential systems made or imported from January 1, 2025 at refrigerants with a global warming potential below 700, and R-410A equipment already in homes remains legal to repair and recharge. A final EPA rule from May 2026 removed the January 1, 2026 deadline for installing R-410A equipment made before 2025, so that older stock can be installed until it runs out.
- New systems use A2L refrigerants.The EPA noted in 2025 that most major manufacturers had already moved new residential equipment to R-454B, a mildly flammable (A2L) refrigerant. If you are quoted a new system, ask which refrigerant it uses.
The free AC refrigerant guide explains these changes in more depth for homeowners.
When an air conditioning repair stops making sense
Most repairs are worth doing. Age is the first thing to weigh: the Department of Energy's home cooling guide lists a life span of about 15 to 20 years for a central air conditioner. A failed capacitor on a 14 year old system is still a sensible repair. A failed compressor or a leaking evaporator coil on that same system, especially one that runs on R-22, is the moment to price both paths.
Ask for the repair quote and a replacement quote side by side, with the age of the equipment, the refrigerant type and the expected life of the repaired part noted. The repair or replace guide lays out the factors, and the AC repair cost guide covers what drives the price of common repairs.
Questions for the company doing the work
- Which component failed, and how did you confirm it? Ask for the reading or to see the part.
- What refrigerant does my system use, and does the repair involve it? If yes, ask about the leak search and how much refrigerant is being added.
- Is the replacement part matched to my equipment? Mismatched indoor and outdoor parts can hurt efficiency and humidity control.
- What warranty applies to the part and the labor? Get the terms in writing; they vary by company and manufacturer.
- What is your ACR license number? Then confirm it yourself on TDLR's website.
Verify the license before work begins. Texas requires anyone contracting to do air conditioning, refrigeration or heating work to hold an Air Conditioning and Refrigeration (ACR) Contractor license from the Texas Department of Licensing and Regulation (TDLR). Ask the company for its ACR license number, then confirm it on the TDLR license search (opens in a new tab). The line does not check this for you.
If your system simply stopped and you have not narrowed down the symptom yet, start with the AC repair triage page. For a no cooling situation with vulnerable people at home, see emergency AC repair.
- Dial the numberAn automated assistant picks up (832) 662-4107 at any hour and asks what you need help with.
- Say what is wrongTell it whether the trouble is cooling or heating, where in the Houston area you are, and what the system is doing.
- Reach a local companyYour call is transferred to an independent, locally owned HVAC company, which gets a short summary of your problem before it answers.
- Work it out with themThat company inspects, quotes, repairs and bills you directly. If nobody can pick up, your name, number and problem are passed on for a call back.
About this line: Houston Air & Heating is a free phone line, not an HVAC contractor. 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. Companies may pay a referral fee. You never pay the line. Read how the line works.