Heating And AC Repair: Why Isn’t the Air Conditioner Working? | Sachse, TX

Heating And AC Repair: Why Isn’t the Air Conditioner Working? | Sachse, TX

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Soon hot summer weather will arrive again in Sachse, TX. No one wants to deal with a broken air conditioner when they’re depending on it to keep their homes cool and comfortable. Most homeowners and landlords are not trained to diagnose and fix air conditioners, or even prevent problems.

Contact a heating and AC repair professional before hot weather arrives to avoid a frustrating and uncomfortable experience. A beautiful summer day can become miserable fast without a working AC unit.

The Joule-Thomson Effect

The Joule-Thomson Effect describes how temperature is dependent on how much energy a molecule carries. Air feels hot when molecules in the air have lots of energy and move around rapidly. Molecules in cold air have less energy. This idea is known as thermodynamics. Thermodynamics in relation to air conditioners mean that when air in an AC unit is not compressed, the temperature decreases and molecules slow down. Compression makes molecules heat up and move faster.

Frozen Evaporator Coils

The cooling process of an air conditioner expands the refrigerant inside an evaporator coil to cool it down. The cold air leaves the air conditioner to lower the temperature inside the home. A malfunction in the unit disrupts the entire system and causes the evaporator coil to let refrigerant cool too much. The coil ices over when inside temperatures fall below freezing.

Blocked Air Flow

Air conditioners contain numerous moving parts and freeze up for many reasons. These parts can stick, break, or become clogged. Every air the conditioning unit requires constant airflow to clear humidity inside the unit and keep cold coils warm. Warm air from a home’s interior keeps the coil warm enough not to freeze.

An absence of sufficient warm air causes the coil to freeze before the condensed water is drained away. The AC will still function, but it doesn’t cool the air and uses a lot of extra electricity.

Dirty, clogged air filters and obstructed air registers interfere with airflow. Check the air filter and make sure registers are clear as soon as an air conditioner freezes. Turn off your AC for 1-3 hours so it can thaw. Replace air filters and clean the registers. Turn the unit back on with just the fan running for another hour. The United States Department of Energy estimates that changing an HVAC filter improves equipment efficiency by 5% to 15%.

Always change AC filters regularly. The manufacturer should include instructions regarding the frequency of filter changes, buy homes with a lot of dust, pet hair, or cigarette smoke and need to have filters changed more often. Inspect air filters regularly and change them whenever they look dirty, even if it is sooner than the recommended date. A heating and AC repair technician can provide advice or take care of routine filter and cleaning maintenance.

Low Refrigerant Levels

Low refrigerant levels and faulty fan operation also prevent air flow. Sometimes kinks occur in refrigerant lines. Refrigerant leaks are a serious problem, and any fix done at home is probably only short-term. An experienced professional heating and AC repair technician with the knowledge to handle refrigerants should deal with coolant leaks.

Adding more coolant without addressing leaks is wasteful and may create a hazard. It may be necessary to replace the machine if a refrigerant leak occurs. Refrigerants must be disposed of according to national and local regulations in Sachse, TX, and technicians need EPA certification.

Faulty Thermostats and Drainage Issues

Other common problems are faulty thermostats and drainage problems. An AC unit condenses water vapor into a liquid that drains outside. This is how it cools the air inside of a home. Ice blocks the drainage hole when coils freeze. Air conditioners are meant to operate within optimum temperature thresholds. Cold nights in summer can disrupt the system and cause problems.

A programmable thermostat is often very helpful in preventing problems during abnormally cold weather. It shuts your air conditioner down when

temperatures fall below 60 degrees. Pay attention to temperature forecasts if you do not have a programmable thermostat. Turn off the air conditioner and open windows to catch cool breezes on cool nights to avoid potential AC unit problems. Your local heating and AC repair professionals can repair or program thermostats in your system.

Signs of Freezing

Several signs indicate air conditioners have a freezing problem. Check the supply registers to see if they are warm. Warm registers often mean a frozen evaporator coil. Open the panel and visually check for ice. Ice almost always means there is a freezing problem, but remember that a lack of ice does not always mean there is no problem.

Ice may build up on the outdoor unit, main pipe in the indoor unit, and the surrounding area. It is sometimes possible to use a hairdryer to unfreeze coils in window AC units. Check drain pipes for blockages such as dirt, leaves, or other debris.

Do not run an air conditioner with frozen coils. Make sure to leave the unit off until all of the ice is thawed. Do not try to pull ice off or chip it away. Attempts to physically chip ice away have a very good chance of damaging several parts of your air conditioner.

Complete thawing can take up to 5 hours, but running an AC unit with frozen coils will damage the compressor. A damaged compressor requires extensive repairs, and the damage is often not fixable. Heating and AC repair technicians have the most current tools to troubleshoot, diagnose, and repair air conditioners.

Unusual or Loud Noises

A new noise requires immediate attention to minimize damage. A rattling noise from an exterior AC unit is often caused by something that fell into the vents, including sticks, leaves, rocks, and other outdoor debris. Outdoor debris is common, but it’s important to clear it immediately so it doesn’t damage the compressor or other parts.

Call a heating and AC repair technician in Sachse, TX to clean debris out of your AC units. Technicians clean debris safely and look for any possible damage. A professional can also evaluate the environment and tell you if trees or bushes are too close to your exterior units. A general rule is keeping shrubs and trees clear of units in a 3-foot radius.

Rattling in outdoor AC units can also be a result of loose or worn-out parts, such as a displaced fan blade, damaged motor, or loose unit panels. Rattling is often the first sign of a problem for older compressors.

Check the panels and tighten any loose screws. Displaced and damaged fan blades are caused by normal wear and tear, debris knocking a fan blade askew, and improper installation. Misaligned fan blades hit the interior of the casing.

Motors produce power for several parts of outdoor AC units, and motors become loose when they break down to old age or debris. Call a heating and AC repair technician to evaluate, repair, or replace faulty parts. Never put off repairs to motors and other parts. Delayed repairs can ruin the unit and spike energy bills.

Grinding noises are usually caused by faulty fan motors and worn bearings. Popping noises in ductwork, especially when air movement starts or stops, is usually a fault in the ductwork itself instead of an AC unit. Call a heating and AC repair technician to make sure nothing is wrong or fix any damage so your air conditioner can do its job cooling your home effectively. Hissing or whistling could be a problem with ductwork, but hissing noises coming from an AC unit frequently indicate a refrigerant leak.

Indoor Water Leaks

The appearance of water anywhere it doesn’t belong inside a home is alarming. Water damage can occur fast and lead to costly repairs. Turn off an AC unit immediately when it leaks water into the house. Clean up the water quickly to prevent damage to ceilings, floors, or furniture, and use a shop vac if necessary.

There are several common causes of air conditioner leaks. Clogged or disconnected condensate drain lines, also known as air handlers, are the most frequent source of leaks. Condensation on the evaporator coil is supposed to flow through the drain line and discharge outside of the home.

A drain line clogged with dirt or debris can cause water to backup or rupture lines. The drain line may not be securely connected, and vibrations may cause lines to come loose. Consult a heating and AC repair technician to inspect and properly secure drain lines.

Indoor air conditioner units, or air handles, in the basement often have drain pans. A condensate pump removes water from the drain pan. Units in an attic or crawl space frequently have gravity drain lines to transport condensation outside.

An older drain pan may be rusted through or develop holes and cracks. The pan overflows if the condensate pump malfunctions. A heating and AC repair technician can repair or replace the pump and install a new drain pan.

Frozen evaporator coils also cause water leaks, but they are another issue entirely. The one advantage to water leaks in this situation is an early warning that may let you contact heating and AC repair professions in time to avoid damaging the compressor.

Air Conditioner Not Powering On

It is upsetting when an air conditioning unit will not power on, but sometimes it requires only a simple fix. Outdoor units lose power when a circuit breaker has been tripped. Locating and resetting the circuit breaker panel is usually a solution in these cases.

Thermostats and Safety Controls

The next most common cause is the thermostat. A broken, non-responsive thermostat can not communicate with the central air system. A heating and AC repair technician fixes faulty thermostats and may examine the circuit breaker as well. Older thermostats may contain mercury, which is a potentially hazardous substance. It is best to let heating and AC repair specialists handle mercury because they are trained to handle and dispose of it safely.

Outdoor condenser units automatically shut down when pressure falls below a certain level. The system should restart when pressure rises again. Pressure changes according to temperature and refrigerant levels. Consult a heating and AC repair technician to check safety controls and performance when a condenser continuously turns on and off.


Numerous wiring networks connect parts of the central air system together. Wires may be exposed above ground or hidden behind walls. Air conditioner function is impaired and unreliable when wires break or erode. This is also a fire risk, so damaged wiring must be addressed immediately.

Uneven Cooling

Uneven cooling is another common air conditioning problem. Ducts transport cooled air throughout a home, and ductwork is sized to match each interior room. Other variables affecting cooling include the amount of sunlight entering the room and possible drafts and air leaks. Dampers in the duct system help control and regulate air flow. Sometimes the control board malfunctions. An experienced heating and AC repair technician can evaluate and fix these issues.

Motors and Compressors

Damaged motors and compressors are also common causes of an air conditioning unit malfunction. Blower motors running at half speed or frozen completely subject the central air system to a great deal of stress. Compressors are the component responsible for circulating refrigerant through AC units.

A faulty compressor can ruin the entire system in an effort to keep up with demand communicated by the thermostat. Call a heating and AC repair professional to replace broken motors or compressors as soon as possible to improve furnace and air conditioner performance and efficiency.

Call the heating and AC repair professionals at K&S Heating and Air in Sachse, TX, to keep your air conditioner tuned up and working correctly. A heating and AC repair technician can diagnose problems quickly or perform routine maintenance that stops problems before they occur. Regular tune-ups also help air conditioners run more efficiently and use less energy.