Homeowner stated that the upstairs unit is not cooling, that h the indoor unit is blowing hot air. Found the condenser unit very low on refrigerant, had 40 psig on the suction/ discharge line,, proceeded to do a leak search, unfortunately we couldn’t pinpoint the leak at this time due to extremely low pressure but we nota significant amount of oil inside the emergency drain pan , highly believe there is a refrigerant leak at the evaporator coil,,, needs to be replaced.