Johnson Controls Air Conditioner DH240N24

Measure the return air temperature (6 feet from the furnace)

Measure the heated air temperature (6 feet from the furnace)

Calculate the temperature rise (difference between heated air and return air)

Is the temperature rise within the range shown on the rating plate and Gas Heat Application Table 4?

Do you need to adjust the blower cfm to correct the temperature rise?

Remove pilot adjustment cover screw

Adjust the clearance for air to the desired level

Replace cover screw after adjustment

Observe through complete cycle to ensure all controls function properly

Close main manual shut-off valve

Shut off all electric power to the unit

Remove screws holding manifold to burner supports

Open union fitting in gas supply line upstream of unit gas valve

Remove gas piping closure panel

Disconnect wiring to gas valves and spark ignitors

Remove manifold-burner gas valve assembly by lifting up and pulling back

Ensure the furnace is turned off before starting the adjustment

Gather necessary tools for adjustment

Remove the cap on the regulator next to the push-on electrical terminals

Measure the current manifold gas pressure

Measure the manifold gas pressure after adjustment

Is the manifold pressure within the range of 3.35 to 3.95 IWG?

Turn off all other gas appliances connected to the gas meter

Measure the time needed for one revolution of the hand on the smallest dial on the meter with the furnace turned on

Enter the size of the test dial increment (1/2 or 1 cubic foot)

Calculate the cubic feet of gas consumed per hour using the Gas Rate - Cubic Feet Per Hour Table 31

Is the actual input within 5% of the furnace rating?