Tech arrived on site and started maintenance on 1 hvac 3 ton split system. Cleaned coils and checked electrical. All was good in condenser. Refrigerant charge appeared low. However the outdoor and indoor temperature was low as well. Went inside and found the bulb for the air scrubber was out. Recommended installed a phenomenal air. Also found the gas valve for the furnace to be faulty. Same with the thermostat. Will cover under parts warranty.