York Single Package Air Conditioner ZF120N24D7A1BAA1A1

Ensure the use of appropriate pipe dope

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

Blow out loose particles from the piping

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

Verify that the ZF120-150 unit is properly phased at the factory.

Is the compressor rotating in the correct direction?

Is the scroll compressor drawing normal amperage?

Are the suction and discharge pressures normal?

Is the noise level of the scroll compressor normal?

Is the electrical connection to the unit correctly phased?

Gas Connection and Pressure Check

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

Check all joints for leaks using soap solution or other suitable material. NEVER USE A FLAME.

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

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?