What is a likely cause of water running out of an air handler?

Water running out of an air handler is typically caused by a blocked condensate line. When the air conditioning system operates, it removes moisture from the air, and this moisture collects in a drain pan. The condensate line is responsible for transporting this water away from the air handler to prevent overflow. If the line becomes blocked, usually due to algae, dirt, or debris, the water cannot drain properly and will overflow, leading to the issue of water leaking out of the air handler.

In contrast, a low refrigerant charge affects the system's cooling efficiency and can lead to freezing, but it does not directly cause water leakage. A faulty thermostat impacts the temperature regulation of the space and does not usually cause water to overflow. Additionally, inadequate duct insulation relates to energy loss and temperature control but does not influence the drainage system directly.