York Single Package Air Conditioner ZR078N15A2AAA50124A

Close main manual shut-off valve

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

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

Disconnect wiring to the gas valve

Remove the manifold & gas valve assembly

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

Remove cover screws covering HI and LO pressure adjustment screws

Set thermostat to call for second stage heat and start furnace

Enter the current manifold pressure for second stage (100% input)

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

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

Blow out loose particles from the piping.

Have all gas lines external to the unit been purged of air?

Inspect the unit for visible damage during transit

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

Request inspection by the carrier’s agent in writing

Is the furnace disconnected from the gas supply piping system?

Enter the pressure of the gas supply piping system

Is the pressure of the gas supply piping system equal to or less than 1/2 PSIG?