SERVICE CALL NO COOL UPSTAIRS SYSTEM. REPLACED FILTERS ON BOTH SYSTEM. UPSTAIRS EVAP COIL FROZEN. DEICE COIL BY TURNING ON HEAT. RINSED CONDENSOR COIL WATER ONLY. CHECKED REFRIGERANT IN SYSTEM AND FOUND REFRIGERANT LOW. SYSTEM IS 15 YRS OLD CUSTOMER WANT FREON ONLY. ADDED 3lbs R22 UPSTAIRS SYSTEM NO WARRANTY ON REFRIGERANT.