York Single Package Air Conditioner ZJ090C24R4B5EAA1A1

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

Check that all filters are in place and clean

Are the filters clean and undamaged?

Clean or replace filters if necessary

Ensure filters are installed ahead of evaporator coil

Is the unit operating with filters properly installed?

Ensure panel latches are properly positioned for an airtight seal

Ensure no open flames are present in the area.

Use only approved pipe dope for assembling pipes.

Approved compounds for pipe assembly

Gas Pressure and Leak Detection

Open the main shut-off valve to admit normal gas pressure to the mains.

Check all joints for leaks using a soap solution or other suitable material.

Were any leaks detected during the inspection?

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

Adjustment of Second Stage Pressure

Remove plastic cap covering HI and LO pressure adjustment screws

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?

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.

Are the suction and discharge pressures normal?

Is the noise level of the scroll compressor normal?