Working on an AC maintenance on a Lennox system, checked all electrical components and tightened all connections on indoor and outdoor units, checked amps, volts, pressures, vacuumed drain line, rinsed condenser coil and polished units, checked blower, heat, thermostat, batteries, and float switch. Cleaned the interior and exterior of indoor unit with disinfectant, installed new filter, drain pan strip and batteries in thermostat.