York Single Package Air Conditioner ZJ120E24R4B5EAA1A1

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

Record the deflection force used

Re-tighten nuts (A) after adjusting

Verify proper compressor rotation

Check for low amperage, similar suction and discharge pressures, or high noise level in scroll compressors

Inspect electrical connection for misphasing

Change the phasing of the Field Line Connection if necessary

Check for proper supply air blower rotation

Verify if the blower is rotating backwards

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 (HI) manifold pressure

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

Ensure main manual shut-off valve is closed and all power to the unit is shut off

Open the union fitting just upstream of the unit gas valve and downstream from the main manual shut-off valve in the gas supply line

Remove the screws holding each end of the manifold to the manifold supports

Disconnect wiring to the gas valves and spark igniters

Remove the manifold & gas valve assembly

Inspect and/or replace orifices

Remove the heat shield on top of the manifold supports to access burners

Ensure burners are level and seated at the rear of the gas orifice