If your air conditioner is blowing cold air initially and then switches to blowing warm air after running for a while, there are several potential reasons for this behavior. Below are some common causes for this issue:
Icing on Evaporator Coil: If the evaporator coil, which is responsible for cooling the air, becomes excessively cold, it may start to freeze and form ice. When this happens, the airflow passing through the coil is restricted, leading to reduced cooling capacity. As a result, the air conditioner may blow warm air instead of cold air. Icing can be caused by issues like restricted airflow due to dirty air filters, low refrigerant levels, or problems with the system's defrost cycle.
Refrigerant Leak: Low refrigerant levels can affect the cooling process, causing the air conditioner to blow cold air initially, but as the refrigerant level decreases further, it can lead to warm air blowing. Refrigerant leaks require professional attention, as simply adding more refrigerant without fixing the leak won't solve the problem in the long term.
Compressor Issues: The compressor is a crucial component of the air conditioning system, responsible for compressing the refrigerant and circulating it through the system. If the compressor is failing or not functioning optimally, it may not cool the air effectively, resulting in warm air blowing.
Thermostat Problems: A malfunctioning thermostat could incorrectly sense the room temperature or not send the proper signals to the AC system. This can cause the AC to stop cooling even when it's supposed to, leading to warm air being blown.
Airflow Restrictions: Restricted airflow due to clogged air filters, blocked vents, or issues with the blower motor can hinder the air conditioner's cooling performance and lead to warm air blowing.
Outdoor Unit Issues: Problems with the outdoor unit, such as a malfunctioning fan or dirty condenser coils, can impact the overall cooling process and result in warm air being blown.
Electrical Problems: Faulty wiring, relays, or capacitors can disrupt the normal operation of the AC system, causing it to switch from cold to warm air.
To address the issue effectively, it's best to contact a qualified HVAC technician to inspect your air conditioning system. They can diagnose the specific problem and perform the necessary repairs or maintenance to restore the proper cooling performance of your air conditioner. Regular maintenance of the AC system is essential to prevent such issues and keep your unit running efficiently.