Top 10 Reasons Why My AC Doesn’t Work
- 1. Thermostat Issues
- 2. Dirty Filter
- 3. Breaker or Service Switch is Off
- 4. Failed Capacitor
- 5. Failed Contactor
- 6. Dirty Condenser Coil or Evaporator Coil
- 7. Failed Condenser Fan Motor or Blower Motor
- 8. Unit Frozen
- 9. Refrigerant Leak
- 10. Failed Compressor
Thermostat Issues
Some issues with a thermostat can be as simple as changing the batteries or tightening the wires. Other times the thermostat may have failed completely. Either of these can prevent your system from turning on.
Dirty Filter
When a customer calls because there is no cool air in their home, one of our first questions is how long it has been since the filter was changed. Most people don’t realize just how important it is to change their filter. Most 1” filters are designed to protect the system from debris in the air building up within the furnace and coil, not to filter the air. A dirty filter blocks the air from correctly flowing through the system preventing it from operating properly.
Breaker or Service Switch is OFF
A service switch is a light switch on the side or very near the furnace. Sometimes the switch is flipped to the off position. This can also happen to the breaker in the breaker box. Sometimes it is as simple as flipping the switch or breaker to the on position. Other times there is an underlying issue that is causing the breaker to trip. You can certainly flip the breaker, but if it doesn’t reset or stay reset, then you want to have a technician figure out the cause.
Failed Capacitor
A Capacitor on your Air Conditioner provides the initial boost of stored electricity to certain components like your condenser fan and your compressor. When it is outside of tolerance, it can be more difficult for those components to start. This is a much harder condition for your system to operate and can reduce the longevity or performance of your Air Conditioner. When your capacitor fails completely your AC won’t operate. Often the capacitor can simply be replaced by an HVAC professional, and the system will operate normally again. It is, however, possible that running the unit on a failed capacitor damaged the unit component it was assisting enough that the part will have to be replaced as well. These situations can be frustrating to homeowners because sometimes a technician cannot tell if the part is out without replacing the capacitor first.
Failed Contactor
A contactor controls the flow of electricity to the electrical components in your condenser. If a contactor is not working, then the parts in your Air Conditioner can’t turn on. If you hear a chattering or buzzing noise from the condenser it is likely that the contactor is at fault. If you see visible signs of wear, pitting, or melting on the contactor, then it is failing. The only thing that can be done is to replace the contactor and if tht’s the only thing wrong with the unit, it will start again.
Dirty Condenser Coil or Evaporator Coil
It doesn’t matter if the coil is inside or outside, debris like dirt, dust, hair, and many other small light weight particles are the enemy of your evaporator or condenser coil. Simply moving air past them, this debris will collect on a coil and if not routinely cleaned (especially condenser coils) or proper filter changes at the furnace occur (inside evaporator coils) this debris will cause a system to lose efficiency, effectiveness, and longevity. Remember, an air conditioner is a heat rejection machine. If the air can’t move past the coil appropriately, then the heat can’t be absorbed by the coil and refrigerant. If it doesn’t get absorbed, then it can’t be transferred outside, thus the home won’t get cooled off. Many, many times service technicians are called to homes in the middle of hot summers and the condition of a coil is the cause of the unit not cooling. Often routine maintenance alone can prevent these frustrating situations for homeowners from happening.
Failed Condenser Fan Motor or Blower Motor
A condenser fan is powered by a motor and together they move heat past the coil on your air conditioner. The blower motor and wheel move the air through the furnace, your coil, and throughout your home. The first clue that a condenser fan has failed is that air is moving, but no cool air is coming out. If a blower motor is out, there will be no air moving throughout the home. When either of these two motors fail, your system can’t operate and properly cool your home. These issues require an experienced technician to come diagnose the issue and replace the failed part. Both issues are common and can often be repaired the same or next day.
Unit Frozen
Another question we often ask customers who are calling in with AC issues is “Is there ice around the coil or AC?” There are only 2 reasons a unit is frozen. The most common reason is improper airflow. You can’t imagine how often this is simply a dirty filter. A 1” filter is designed to be replaced every month, a 4” or 5” filter is designed to be replaced every 6 months. Poor airflow can also come from other obstructions in the house, ductwork, or coil. The second thing that can cause an AC to freeze is improper refrigerant charge, normally low. Filters and obstructions are relatively easy to remedy. If a unit has a refrigerant leak, it can be a more serious issue. Turn the unit to blower only to allow the ice to thaw and call a technician to diagnose the problem.
Refrigerant Leak
A home’s refrigerant system is a hermetically sealed system. It is under vacuum and thus should never need to have refrigerant added. So, when a refrigerant system is low on charge it reduces the ability of the indoor coil to absorb heat from the home. This lowers the effectiveness of the unit to cool the home. As the compressor continues to operate and attempts to cool, the evaporator continues to get colder. Eventually, the coil gets below 32 degrees and the condensation on the coil freezes. The unit must be thawed to find the leak and perform the repair. Turn the unit to blower only to allow the ice to thaw and call a technician to diagnose the problem. Once the leak is fixed the unit can be properly charged and should then cool properly.
Failed Compressor
The compressor is the heartbeat of your Air Conditioner. The refrigerant absorbs heat inside your home and the compressor moves the refrigerant outside to be cooled off outside then the cycle repeats. A Compressor can fail for many reasons. Electrical problems can come from voltage fluctuations or improper wiring that can overheat the internal components and cause the unit to overheat, and the compressor to fail. Refrigerant levels being off can also cause it to fail. Refrigerant is an oil, thus the lubricant for the unit. If the lubricant is low, it can cause the unit to overwork and fail.
Annual Maintenance is Key!
Poor maintenance reduces the Air Conditioner’s ability to absorb or remove heat. This is extremely harmful on the unit and compressor. This can easily cause premature failure. These failures are some of the most common and frustrating issues that homeowners face with their HVAC systems. During a cooling maintenance, your filter should always be changed, connections and capacitors checked, condenser coil cleaned, overall working condition of the unit checked, and several other tasks performed. If you are not currently participating in an annual routine maintenance program, you should seriously consider joining one, whether with Summit Heating and Cooling or not. It’s like changing the oil in your car and is the best money you can spend on your system and your family’s in home comfort.
If you are in the Kansas City Metro Area, give us a call and have one of our experienced technicians help you with all your in-home comfort needs. Remember, If you’re looking for the top, Reach for the SUMMIT!
