York Single Package Air Conditioner ZF120N24B7A1BAA1A3

Check that all filters are installed ahead of the evaporator coil

Inspect filters for dirt and debris

Clean or replace dirty filters with the same size and type

Ensure the unit is not operated without properly installed filters

Verify that panel latches are properly positioned to maintain an airtight seal

Connect a manometer to the outlet pressure port on the gas valve

Remove plastic cap covering HI and LO pressure adjustment screws

Second Stage Pressure Adjustment

Set thermostat to call for second stage heat and start furnace

Adjust the second stage adjustment screw to set manifold pressure

Enter the manifold pressure for second stage

Loosen six nuts (top and bottom) A

Ensure nuts (C) are not loosened

Use belt tension checker to apply a perpendicular force to one belt at the midpoint of the span

Enter the deflection distance obtained (mm)

Enter the deflection force applied (N)

Is the deflection distance 4mm (5/32”)?

Is the deflection force within the recommended range?

Inspect the unit for possible damage during transit

Note the extent of the damage on the carrier’s freight bill

Request inspection by the carrier’s agent in writing

Ensure installation complies with all applicable codes

Ensure the use of appropriate pipe dope

Clean piping of dirt and scale by hammering on the outside of the pipe

Blow out loose particles from the pipe

Purge all gas lines external to the unit of air before initial start-up