York Single Package Air Conditioner ZJ090N24R4B5EAA1A1

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

Inspect the unit for possible damage during transit.

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

Request inspection by the carrier’s agent in writing.

Ensure installation complies with enclosed instructions and applicable codes.

Is the furnace and its individual shut-off valve disconnected from the gas supply piping system?

Check that all filters are installed ahead of the evaporator coil

Inspect filters for dirt and debris

Replace filters with the same size and type if necessary

Ensure the unit is not operated without filters properly installed

Verify 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 second stage (HI) manifold pressure using a screwdriver

Enter the second stage manifold pressure reading

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

Enter the deflection force applied

Check belt tension at least two times during the first 24 hours of operation

Re-tighten nuts (A) after adjusting