It has happened to most of us, and usually during a particularly hot and humid summer day. You’re uncomfortable and detect that your air conditioner is blowing warm, instead of cool, air!
Often there is an easy fix to this common problem. Is your system set to heating instead of cooling mode? The first recommended step is to check your thermostat settings, which can easily get switched, especially during the changeover between seasons. It should be set to “cool” mode and the fan switched to the “auto” position. Make sure the temperature setting is below what the actual room temperature is.