Aaon HVAC Unit RN-016-4-0-CB

Is the fan at normal operating temperature?

Select the grease used for lubrication

Measure the current sub-cooling temperature

Measure the current superheat temperature

Is the system overcharged or undercharged?

Is the sub-cooling temperature too high and evaporator fully loaded?

Reduce the amount of refrigerant in the system to lower the sub-cooling

Set unit controls to cooling mode of operation with supply fans on

Is the fan operating in the correct direction?

Is the compressor operating correctly?

Is the compressor rotating correctly?

Shut off all electrical power to the unit to avoid shock hazard or injury from rotating parts.

Check the gas pipe in the unit for leaks before startup.

Disconnect all wiring on the heat exchanger.

Disconnect flex gas lines and pull out of the way.

Remove screws around the perimeter of the heat exchanger face plate that connect it to the unit. Only the outermost screws should be removed.

Pull the heat exchanger straight back and out of the unit.

Was it necessary to remove some of the control door jambs?

Inspect the vent outlet for debris or foreign matter

Is the vent outlet clear of debris?

Check the vent outlet each time air filters are changed