Performed a tuneup on AC system. Inspected indoor outdoor coils, cleaned and flushed drain line, replaced air filter, inspected blower wheel, checked temperatures, checked static pressure, checked refrigerant pressures, inspected all major and minor electrical components. Upon arrival drain line was backed up and float switch was not triggering unit off. Also system only has one return grill, which is being blocked by the water heater, recommended replacing float switch, installing an in-line drain cleaner, and installing 2 return air grills. Client declined recommendations at this time. Cycled and tested system, all operations OK.