York Single Package Air Conditioner ZF120N24R2A1BAA1A1

Close main manual shut-off valve

Disassemble Gas Line and Manifold

Open the union fitting upstream of the unit gas valve

Remove screws holding the manifold to the supports

Disconnect wiring to the gas valves and spark igniters

Remove the manifold & gas valve assembly

Inspect and/or Replace Orifices

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 second stage adjustment screw to set manifold pressure

Is the second stage manifold pressure within 3.5 IWG ± 0.3?

Verify that the unit is properly phased at the factory.

Is the blower rotating in the correct direction?

Is the compressor rotating in the correct direction?

Measure the amperage of the scroll compressor.

Is the scroll compressor drawing low amperage?

Are the suction and discharge pressures similar?

Is the scroll compressor producing a high noise level?

Loosen six nuts (top and bottom) A

Ensure nuts (C) are not loosened

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

Enter the deflection distance obtained (mm)

Enter the deflection distance obtained (inches)

Enter the deflection force applied (N)

Enter the deflection force applied (lbs)

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 local, state, and national codes

Verify compliance with building, electrical, and mechanical codes