Aaon HVAC Unit RN-055-3-0-EW

Verify that all safety protocols are in place

Inspect the following components for wear and tear

Clean the unit exterior and interior

Is the operating pressure within the normal range?

Ensure only clean water is available for cleaning

Is the water pressure set to not exceed 140 psi?

Position nozzle 6 inches from coil face at an angle of 80° to 90°

Ensure water is aimed perpendicular to the coils from no closer than 3 inches

Is the cleaning solution pH between 5 and 9, if used?

Are detergents or coil cleaners avoided?

Gather necessary cleaning tools and materials

Inspect the drain pan for moisture and microbial growth

Remove any standing water from the drain pan

Clean the drain pan with an appropriate cleaning solution

Inspect and clean the drain lines to prevent plugging

Measure the temperature of the liquid line as it leaves the condenser coil

Read the gauge pressure at the liquid line close to the point where the temperature was taken

Convert the pressure obtained to a saturated temperature using the appropriate refrigerant temperature-pressure chart

Subtract the measured liquid line temperature from the saturated temperature to determine the liquid sub-cooling

Compare calculated sub-cooling to the table below for the appropriate unit type and options

Temperature and Pressure Measurement

Measure the temperature of the suction line close to the compressor

Read gauge pressure at the suction line close to the compressor

Temperature Conversion and Calculation

Convert the pressure obtained to a saturated temperature using the appropriate refrigerant temperature-pressure chart

Subtract the saturated temperature from the measured suction line temperature to determine the evaporator superheat

Compare calculated superheat to the table below for the appropriate unit type and options