5 Most Common Air-Conditioning Problems and Repairs

​It's not necessary to be an expert in air conditioners to identify problems. Understanding the most typical issues that AC units face is quite helpful in averting malfunctions. Who wants to spend a steamy summer in Denver indoors without air conditioning? Be mindful of these ten typical problems:

Why Is My Air Conditioner Not Cooling the House?

Make Sure the Furnace Isn't the Issue

Reduce the temperature and put your thermostat in the AC mode. If the fan in the furnace turns on, there isn't an issue with the furnace. To ensure that the fan operates, attempt to reset the furnace's circuit breaker. The solutions outlined here won't work, so contact an expert if the fan still won't start.

Next, examine the external condensing unit. The fan and compressor ought to be operating; the compressor makes a refrigerator-like noise. If not, carry out the troubleshooting and repairs as outlined below.

Turn off the power, please.

​Pull the outdoor disconnect or remove the access panel from the condensing unit after turning off the furnace and A/C breakers in the main electrical panel. Subsequently, ensure that the power is indeed off by using a voltage tester on the cables entering the contactor.

Does Your AC Not Work? Purchase Parts

​The most common and affordable components to fail are the start/run capacitor(s) and AC contactor (relay) (see image below). Therefore, it is important to purchase and install those parts as soon as possible, particularly if your air conditioning repair unit is more than five years old. You should wait to acquire a condenser fan motor replacement until you are certain that it is the cause of the failure, as they can cost up to $150.

Locate the nameplate on the condensing unit (not your furnace) to purchase replacement parts. Record the model, make, and serial number (or snap a picture). Purchase the parts online, at a furnace dealer, or at an appliance store.

Discover How a Central Home Air Conditioner Works

​The two main parts of a central air conditioning service system are the evaporator coil, also known as an A-coil, which is located in the plenum of your furnace or air handler, and the condenser, which is located outside your home. Heat from your house is transferred to the outside condensing unit by the refrigerant in the A-coil. 

To remove heat, outside air is blown through the condensing coil by the condensing unit fan. The condensing unit contains the three parts—the condenser fan motor, the start/run capacitor(s), and the AC contactor—that an amateur handyman may repair. The compressor is likewise housed in the condensing unit, however it can only be replaced by an expert. There are no DIY-friendly elements on the A-coil.

Shut Off the Power

• Pull the disconnect block out of the electrical box that is next to the condensing unit after opening it.
  
• Use a voltage sniffer to confirm that the power is truly off within the box.

Condenser coil cleaning

An air conditioner condenser can be cleaned quite easily, and doing so is one of the routine maintenance procedures that will increase the unit's lifespan.

• To get rid of the crud accumulation under the cover, aim your garden nozzle upward into the top of the condenser coil.
  
• Work your way around the coil completely. After that, point the nozzle downward and clear the debris from the coil fins.
  
• To remove any last bits of debris, turn the nozzle to a softer stream and jet water straight into the coils.

Test the Fuses

Two cartridge fuses are found in many disconnect blocks. Before you start fixing them, check them. A blown fuse indicates a malfunctioning component within the condensing unit. Thus, avoid simply replacing it and declaring the issue resolved. Instead, put in new fuses, reinstall the parts, and turn the unit on. You have more significant problems; call a professional if it blows again.

How the Disconnect Block Fuses Can Be Checked

• Touch the red and black leads to the opposing ends of each fuse after setting your multimeter to the lowest Ohms scale.
  
• If the reading is numerical, the fuse is functioning properly.
  
• A blown fuse is indicated by a zero, negative symbol, or infinity symbol (∞).

Examine the Access Panel's Interior

​Locate the access panel by following the electrical conduit that comes from the home. Turn off the electricity and take out the access-panel retaining screws before removing the panel. Look for mouse nests or signs that the wiring and electrical connectors have been chewed on before replacing any parts.

Discharge the capacitor first if you discover damaged wiring or chewed insulation and you are capable of handling electrical repairs safely. After that, tidy the nest and fix the wiring. Or else give a pro a call. What you should know about air conditioner wiring is provided below.

How a Dual Start/Run Capacitor Is Discharged

• Take out the capacitor by unscrewing its holding bracket.
  
• Next, place an insulated screwdriver between the COMMON (or "C") and HERM (or "H") terminals.
  
• Repeat this action between the "C" terminal and the FAN (or "F") terminal.
  
• Simply create a short circuit between the two terminals of single-mode capacitors.

Change the capacitor(s) for the start/run.

​At least one capacitor is present in every air conditioning servicing unit. To offer both motors an extra boost of power during compressor and condenser fan startup, the capacitor stores and releases electricity. Additionally, it evens out voltage swings to prevent damage to the compressor and condenser fan motor.

Over time, capacitors may gradually deteriorate and lose some of their starting power. Or they could collapse at any time. Long-term unrecognized gradual capacitor failure can put stress on the compressor and condenser fan motor windings, causing them to fail sooner than expected. Because capacitors are inexpensive, it makes sense to change yours proactively around every five years.

How a Capacitor Is Replaced

• Prior you disconnecting anything, snap a picture of the cables in case you need a reference later.
•  Release the energy that has been stored in the old capacitor.
•  One wire at a time, remove it from the old capacitor using needle-nose pliers, and then snap it onto the matching tab on the new capacitor. The capacitor tabs should be securely snapped onto by the female crimp connectors.
• Check the tightness of each connector by wriggling it. If not, take out the connector and bend its rounded sides to fit the tab more snugly.
• After switching out every wire, fasten the replacement capacitor.
  
• Caution: Let the capacitor discharge completely before cutting any wires or taking it out of its bracket.

Change the AC Contactor

An AC contactor is a $25 mechanical relay that switches 220-volt high-amperage current to the compressor and condenser fan using low-voltage electricity from the thermostat. The most frequent causes of air conditioning service failures are worn-out AC contactors. It is wise to replace your AC contactor about every five years, even if it is still functional. To remove the cables, unscrew the original AC contactor. Once at the new unit, relocate the wiring.

• Remove a connection from the outdated contactor and replace it in the same spot on the replacement component.
•  When necessary, tighten the connectors.
•  Secure the condensing unit's new contactor.

How to Evaluate Your Fixes

• Remove the block and replace the access panel.
• After turning on the furnace switch and circuit breaker, lower the thermostat and wait for the air conditioning to start.
• Both the condenser fan and the compressor should be operating.
• If the compressor kicks on but the fan stays off, the fan motor is probably dead.
• Turn off the electricity and take off the fasteners surrounding the condenser cover.
• Lift the lid, then take off the motor and fan blade.
• Put the blade back in place and fasten the lid.
• Next, restart the device to check if the fan turns on.
• If not, you've tried your hardest; it's time to hire an expert. These are some obvious indicators that it's time to replace your air conditioner.