Most Common Air Conditioner Problems and Solutions

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An inefficient air conditioner can get into your nerves and affect your health and mood, especially when the summers are at their peak. Many reasons could cause the AC to shut down and stop its services.

Even if you have proper and regular maintenance of your AC, it could run into some system errors. So, in such situations, the best advice is to call for professional help.

That being said, if you want to assess AC problems yourself you can go ahead. This would help you learn more about your home appliance plus, in some way, it would save you money or be tricked. We have narrowed down some of the most common air conditioner problems and how you can fix them. Let’s begin.

Problems with AC & Solutions

1. The Problem: Low Refrigerant

How to Fix It: When your air conditioner is running low on refrigerant fluid, your AC would not blow out cool air in the room. The best solution to fix it is to find out the leakage signs and contact the technician right away. Here are some signs that suggest you are low on the refrigerant level:

  • Vents not blowing cool air.
  • Ice on refrigerant lines.
  • Hissing noise.
  • Evaporator coil freezes.

The only reason you may run low on the refrigerant level is due to leakage in the AC system. So, if you are skeptical about this condition don’t add more refrigerant fluid as it would escape again.

2. The Problem: Air conditioner not cooling

How to Fix It: This is one of the most common problems faced by AC users. To fix this problem, you will have to understand the causes and then take the necessary action. Here are some common causes and solutions:

  • Improper AC unit placement could affect cooling. To fix this, make sure your indoor unit is not undersized and the outdoor unit is clean, away from direct sunlight or high temperature.
  • A dirty air filter obstructs cooling. Clean it on regular basis or replace it if necessary.
  • Irregular maintenance is another reason why your AC is not cooling your room. Fix this by having a proper check-up once a year from a professional company.
  • Faulty components could make the AC unit inefficient and could result in no cooling. Make sure the AC unit is from a reputed brand and covers damages for a longer period.

3. The Problem: Thermostat Glitches

How to Fix It: A thermostat is a component that detects the temperature of the surroundings and helps to set the desired temperature according to the need. If there is a malfunction in a thermostat, the HVAC system operates poorly and you will experience strange cooling and heating behavior. To solve this problem check the following things:

  • Double-check the thermostat settings.
  • Check whether the wiring is on point.
  • Check if the thermostat batteries need replacement.
  • A software bug could affect the thermostat too, contact the manufacturer if such a problem arises.

4. The Problem: Strange Noises from AC

How to Fix It: Another common problem found in the air conditioner is unrecognizable noises. Here are seven common noises and what they mean.

SoundPossible Causes
BuzzingUnclean AC coils, issues with the motor, loose parts, bad blower, and refrigerant leakage.
SquealingIssues with belt, indoor and outdoor blower motors.
ScreamingPressure in the AC compressor, refrigerant leakage.
ClickingIssues in the thermostat or control unit.
ClankingLoose parts.
BangingBroken or loose parts, sign for replacing the AC compressor.
RattlingLoose fan, leaves clogging the duct, a sign of deterioration.

All the sounds mentioned above are an indicator of a poor AC system, so make sure you don’t ignore it and have a check-up as soon as possible.

5. The Problem: AC coil is frozen

How to Fix It: An air conditioner coil plays a vital role in heat exchange, any problem in this unit is a serious problem. The most common reasons that freeze the AC coil are – unclean air filters, refrigerant leakage, broken fans, issues in the thermostat, and clogged condensate lines.

To solve this problem, first, turn off the air conditioner to save other units from potential damage. Leave it for a few hours and let the ice melt, you can use a hairdryer to melt the ice faster. It is important to note that you don’t cut off the ice as it could damage the AC coils. If this problem arises again, contact the technician.

6. The Problem: AC blows bad odor

How to Fix It: This problem could occur due to mildew or mold growing in your system or because your air filter is not clean. The bad odor could also blow in due to electrical parts getting overheated. Fix this problem by changing the filter, cleaning the evaporator coil, and condenser line, and not running the AC for long hours.

7. The Problem: AC fan is not working even the power is on.

How to Fix It: When you are in such a problem, it would most probably mean the circuit inside the system is broken, the fan motor is burnt, the belt is broken or there is an ice-build up inside the AC coils. This calls for professional help.

8. The Problem: AC Condenser is not working

How to Fix It: When the condenser is not working you will find the following problems:

  • Uneven room temperature
  • The unit is turned ON but does not cool the room at all.
  • The condenser is completely shut down.
  • You receive higher energy bills.

The common causes that result in malfunctioning of an AC condenser are:

  • Faulty motor and compressor.
  • Wiring issues
  • Insufficient refrigerant
  • Unclean condenser and evaporator
  • A problem with the thermostat.

To solve the problem, you could either repair or replace the unit. While calculating the repair cost, if you find that the repair cost is above 50% of your unit’s value, it is advisable to replace it.


An air conditioner is a mechanical device that could create system problems sooner or later. Some problems are minor while some could completely damage the entire system, this means ignoring such problems could have bad consequences.

Some of the most common problems that you will find in an air conditioner are – insufficient refrigerant, condenser and fan not functioning, bad odor in the room, thermostat glitches, improper cooling, frozen coils, and strange noises. All the problems listed above have brief solutions that you can follow.

The idea is to help you learn more about the air conditioner so that you could troubleshoot most of your AC related problems and save resources. Good luck!

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