The answer to 'air handler blowing cold air' is that there are several common causes, including a problem with the thermostat, a refrigerant leak, a malfunctioning compressor, or a clogged air filter. Symptoms may include the air handler continuously blowing cold air, even when the system is supposed to be in 'heat' mode.
Some potential solutions include checking the thermostat settings, inspecting the air filter and replacing it if needed, and calling an HVAC professional to diagnose and repair any issues with the refrigerant system or compressor. It's generally best to have an HVAC technician handle these repairs, as they require specialized knowledge and equipment.