Air conditioning repair. Upon arrival, homeowner explained that for the past few days the system has been working intermittently never cooling lower than 78°. Found thermostat on and both systems with power. Drain line completely clogged and backflowing through float switch. Vacuumed condensate drain line and vacuum out bacterial growth evaporator coil pan. Restarted system after clearing drain line. Advised homeowners to use distilled white vinegar in drain line once a month.