Performed 1 system diagnostic for zoned unit that services the master and bonus room. Found evap coil frozen. Standing pressure for R22 system extremely low nd when removing and putting on gauges not refrigerant found only air. Dirty blower wheel, rusted evap coil, failed dual capacitor, and pitted contactor as well. Unit is zoned and located in the garage closet. Burners show evidence of multiple occurrence of freezing and thawing and rust in the burner cabinets. Unit is left on fan only for air circulation system is non operational at this time. Based on our findings today, it might be time to think about getting a brand new system.