HVAC

AC Repair – Common Causes and Symptoms of Contactor Failure

AC Repair Round Rock can be costly, but regular maintenance reduces energy costs and prolongs the life of your system. It also improves air quality and decreases humidity levels in the home.

Changing filters, cleaning the exterior unit, and resetting tripped breakers are simple fixes that anyone can do. However, if you suspect a refrigerant leak or other electrical issues, call a professional.

AC Repair

1. Evaporator Coil Clog

Over time your evaporator coil can become coated in dirt, dust, and airborne debris. This coating inhibits the coil’s ability to absorb heat from your home’s air, and will diminish its overall performance capacity.

Clogged evaporator coils usually occur because of a lack of regular cleaning and maintenance. However, they can also be caused by a dirty air filter, low refrigerant, a malfunctioning blower fan or a poor installation job.

Regardless of the cause, a clogged evaporator coil is a serious problem. It can lead to hissing and banging sounds, inefficient cooling, increased utility bills, poor indoor air quality and even the need for costly AC repair.

One of the first symptoms of a clogged evaporator is a puddle under your unit. The puddle could mean that the coil is frozen and melting water is collecting beneath it, or that the system is leaking refrigerant into your home. Either way, it’s important to turn off your air conditioning and call a professional right away.

Another sign of a clogged evaporator may be the smell of refrigerant in your home. Older AC systems typically use R-22 refrigerant which has a distinctive and pungent odor. Newer systems often use R-410A which has no odor and is nontoxic.

A clogged evaporator coil will cause your air conditioner to short cycle. The coil will be unable to absorb and transfer enough heat from the air to your home’s air, so it will shut off before the proper temperature is achieved. This puts unnecessary stress on your AC and can cause damage to your evaporator coil, compressor and other components.

To avoid a clogged evaporator, regularly clean your AC coil with a brush or vacuum attachment. Make sure the power to your air conditioner is off before opening the access panel, and then carefully remove any buildup of dirt or sediment from the coil. Also, make sure to drain the condensate pan regularly and keep it sealed and free of blockages. It’s also a good idea to change your air filters frequently and ensure that all of your vents are open and unobstructed.

2. Failed Contactor

The air conditioning mechanism that directs the flow of electricity to the compressor and fan motor is called a contactor. It is a critical component of the system but like other electrical components it can wear out or develop faults over time due to continuous operation and environmental factors. When the contactor fails, it disrupts the normal flow of energy and may cause intermittent or even complete AC failure. Understanding common causes of contactor problems and the related symptoms can help homeowners and technicians address them promptly to restore reliable operation.

Basically, the contactor is an electromechanical switch that connects and breaks the power supply lines running through an appliance or equipment. It consists of a metal coil, stationary contacts, and movable ones that latch onto each other when the coil is energized to close the circuit. When the coil is de-energized, the movable contacts separate to break the current and stop the equipment from operating. Over time, the mechanical shock and vibration from continued use can damage the coil and the movable contacts and make them difficult to latch or separate correctly.

One of the most common signs that a contactor is failing is short-cycling, which is when the air conditioner turns on and off frequently in quick succession. This is often because the contactor fails to stay closed for a proper amount of time, leading it to run more than necessary to cool your home.

Another sign is a chattering sound that can occur when the metal plunger and contactor coils erode. When this happens, they begin to vibrate and make a clicking noise as they attempt to latch and separate. This is an indication that it’s time to replace the contactor and should be done as soon as possible.

Faulty contactors can also introduce power surges and fluctuations into the AC circuit, causing other components within the system to overheat. If you notice discoloration, burn marks or pitting on the contacts, this is a clear sign that the contactor needs to be replaced. It is important to consult with a licensed HVAC technician to ensure the replacement is done correctly and doesn’t cause additional problems.

3. Failed Blower Motor

Blower motors are vital to the air conditioning system, as they blow heated or cooled air throughout the home through vents. When a blower motor fails, it can significantly reduce the comfort and efficiency of your AC system. A few symptoms of a failing blower motor include a slapping sound, limited fan speeds, and unusual smells. If you notice any of these signs, contact your local HVAC professionals as soon as possible to schedule a professional inspection and repair service.

Weak or No Airflow

Weak or no airflow from your AC vents can indicate a variety of problems, including clogged filters, dirty or leaky ducts, and an aging blower motor. However, the most common cause of weak or no airflow is a faulty blower motor, which may be suffering from a dirty or defective capacitor or simply reaching the end of its lifespan. In some cases, a professional can clean the blower motor or replace it entirely.

Unusual Noises

An HVAC technician can diagnose a failing blower motor by listening for unusual noises during the air conditioning system’s operation. A slapping sound, for example, could indicate that a foreign object has fallen inside the blower motor fan blades and is causing damage to the motor itself. Unusual noises can also indicate that the motor is consuming too much energy and is overheating.

A squealing or screeching sound could mean that the blower motor bearings are beginning to wear out. If the blower motor is overheating, it may produce a burning smell, which is a sign of danger and a fire hazard.

Check the breaker or fuse box to ensure that it hasn’t tripped or blown a switch or fuses. If there’s no problem with the circuit breaker, turn on your furnace and verify that the thermostat is set correctly. Next, inspect the blower motor relay, capacitor, and control board for voltage. If the control board is faulty, it will fail to initiate the blower fan on/off function based on the thermostat demand. A multimeter can verify that the control board’s voltage is correct.

4. Refrigerant Leaks

Your AC system needs refrigerant to absorb and release heat in your home, but a leak can cause the entire thing to break down. Refrigerants are highly hazardous to work with and must only be handled by licensed professionals who have the proper safety equipment. If you notice signs of a refrigerant leak, contact your local air conditioning repair company right away.

Your system’s refrigerant circuit is typically made of copper and structured like a coil. Throughout the system, a series of twists and bends are soldered together in order to form the coiled structure. While this design may be sturdy enough to handle high pressure, it’s not immune to corrosion. Over time, natural formic acid eats at the copper and causes leaks.

Fortunately, a simple repair can usually take care of the issue. HVAC technicians will use specialized tools to locate the source of the leak and seal it using epoxy or solder. Depending on the severity of the leak, a technician may also replace the coil or lineset in order to keep your cooling system running efficiently.

The most common sign of a refrigerant leak is low cooling efficiency. The air from the vents will seem warm rather than cool, and it will take longer for your home to cool down. Another symptom is an unusually damp or musty smell in your house. The smell is caused by the evaporator coils absorbing moisture from your home’s air.

Finally, if you hear hissing sounds coming from your vents, it could be due to excess pressure in the compressor. This problem is serious and requires immediate professional attention.