If your air conditioner is cooling to a temperature lower than the set point and not shutting off, it may be experiencing one of the following issues:
Incorrect thermostat settings: Double-check the thermostat settings to ensure that the desired temperature is correctly set. Sometimes, people accidentally set the thermostat too low, causing the air conditioner to continue cooling beyond the necessary point.
Thermostat location: The thermostat's location plays a crucial role in maintaining accurate temperature readings. If the thermostat is located near a cold draft, a heat source, or in direct sunlight, it might not accurately reflect the actual room temperature, leading to the AC running excessively.
Dirty or faulty thermostat: A dirty or malfunctioning thermostat can give inaccurate readings, causing the air conditioner to keep running. Clean the thermostat and ensure it's working correctly. If it's damaged, consider replacing it.
Air leaks: If there are air leaks in your home, warm air from outside can enter, causing the temperature to rise above the set point. The air conditioner will then continue to run to maintain the desired temperature, leading to excessive cooling.
Improperly sized AC unit: If your air conditioner is too large for the space it is cooling, it may cool the room quickly but not cycle off properly. An oversized unit can cause short-cycling, where it turns on and off rapidly without completing a full cooling cycle.
Frozen evaporator coils: If the evaporator coils inside the AC unit freeze due to lack of airflow or refrigerant issues, it can lead to the system continuously running to try to achieve the set temperature.
Malfunctioning compressor or relay: A faulty compressor or relay can prevent the air conditioner from cycling off when it reaches the desired temperature.
Inadequate maintenance: Lack of regular maintenance, such as cleaning air filters and coils, can decrease the efficiency of the AC unit and lead to continuous operation.
If you're unable to identify and resolve the issue yourself, it's best to contact a qualified HVAC technician to inspect and repair your air conditioning system. They can diagnose the problem accurately and ensure your AC operates efficiently and as intended.