CAL
-SERIES
63
SERVICE DOOR
BLACK PLASTIC CAP ADJUSTMENT TOWER
5)
Locate manifold pressure tap. Open the manifold pressure tap by using a small flathead screwdriver
to turn the screw inside the brass fitting counterclockwise 3 turns. DO NOT REMOVE THIS SCREW.
6)
Connect a manometer that registers pressure in inches of water column (“W.C.) to the manifold
pressure tap.
FOR LOW PRESSURE VERIFICATION and/or ADJUSTMENT:
CAUTION: Always adjust low pressure setting first since the low setting will affect the high setting.
7)
Remove the electrical connection from the modulator. (Brown and White Wires)
8)
Start the heater and take a pressure reading. The manifold pressure required on the low setting for
natural gas is 1.25 “W.C. For liquefied petroleum gas, the manifold pressure should be 5.25” W.C. on
low. The manifold pressure setting information is also contained on the rating plate which is affixed
to the side of the heater near where the service lid is located.
9)
If adjustment is needed, insert a 3mm allen wrench into the adjustment tower and turn clockwise to
lower pressure and counterclockwise to increase pressure.
