The answer to 'air handler blowing cold air' is that this is likely due to an issue with the air conditioning system. The air handler is the indoor unit that circulates air throughout your home, and if it's blowing cold air when the system is not actively cooling, it could indicate a problem.
Some common causes include a stuck or malfunctioning thermostat, a refrigerant leak, a problem with the compressor or other components, or even a clogged air filter. In some cases, it may also be caused by a simple wiring or control issue. If the air handler is blowing cold air constantly, it's best to have a professional HVAC technician diagnose and repair the problem to ensure your system is operating safely and efficiently.