A.O. Smith Comprehensive Guide to Water Heater Maintenance: Sizing and Pressure Tubing Removal

PRESSURE TUBING REMOVAL / REPLACEMENT

Important: Use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a qualified service technician.

Tools required: Phillips Head Screwdriver.

Removing the Air Intake Chamber Box:

1.	Set the gas control valve/thermostat to its lowest
	setting by pressing the “COOLER” and “HOTTER”
	buttons together at the same time holding for 1
	second. Then press the “COOLER” button to the
	lowest setting (Figure 74).
2.	Turn gas control switch to the “OFF” position
	(located right side of the gas control valve/
	thermostat) and turn off the gas supply to the unit
	(Figure 75).
3.	Disconnect the electric connection by unplugging
	the transformer from the wall outlet (Figure 75).
4.	Remove the manifold cover/ outer door from the
	unit by depressing on the lower portion and pulling
	outward.
5.	Remove the air pressure tubing from the air
	pressure switch by pulling downward on the
	tubing at the connection to the air pressure switch
	(Figure 76).
6.	Using a phillips head screwdriver, remove the 4
	screws securing the air intake chamber box to the
	water heater’s side (Note: keep these screws in a
	safe place for reinstallation later) (Figure 77).
7.	Rotate the top of the air intake chamber box from
	left to right (only a few inches in both directions)
	while pulling outward at the bottom removing
	the air intake chamber box from the combustion
	chamber pipe saving the air intake chamber
	gasket for reinstallation (Figure 77).
8.	Upon removal of the air intake chamber box,

Figure 74.

HOTTER COOLER

Electronic Control Display

Figure 75.

ON

OFF

ON/OFF

SWITCH

UNPLUGGED

Figure 76.

PRESSURE SWITCH

TUBING CONNECTION

	locate the air pressure tubing at the back of the air
	intake chamber box and unplug the tubing. Note
	the routing of the air pressure tubing through the
	water heater’s opening near the bottom. Remove
	the old air pressure tubing (Figures 76 & 77).
9.	Connect the new air pressure tubing into the back
	of the air intake chamber box by pushing it on the
	connector (Figure 78).
10.	Route the new air pressure tubing through the
	water heater’s opening near the bottom (Note:
	mirrors the position of the old tubing) (Figures 77).

Figure 77.

ROTATE FROM

LEFT TO RIGHT

AND

SCREWS

AIR PRESSURE

TUBING

PULL OUTWARD

CHAMBER GASKET

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