Features And Components; The Eliminator (Self-Cleaning System); Automatic Flue Damper; Uncrating - A.O. Smith BTR 120-400 Service Handbook

FEATURES AND COMPONENTS

THE ELIMINATOR (SELF-CLEANING SYSTEM)

These units include The Eliminator (Self-Cleaning System) installed in the front water inlet. The Eliminator
inlet tube can only be used in the front water inlet connection. Do not install the Eliminator inlet tube in either
the top or back inlet water connection. The Eliminator must be oriented correctly for proper function. There
is a marked range on pipe nipple portion of the Eliminator, that must be aligned with top of inlet spud. A label
above the jacket hole has an arrow that will point to marked portion of pipe nipple if the orientation is correct.
If the arrow does not point within the marked range on pipe nipple, adjust the pipe nipple to correct. A pipe
union is supplied with the Eliminator to reduce probability of misaligning the Eliminator accidentally while
tightening the connection to inlet water supply line. Improper orientation of the Eliminator can cause poor
performance of heater and can significantly reduce outlet water temperatures during heavy draws.
THE ELIMINATOR MAY HAVE 1, 3 OR 7 CROSS TUBES

AUTOMATIC FLUE DAMPER

All units are equipped with an automatic flue damper that reduces heat loss during the OFF cycles. The
automatic flue damper drive assembly is a field replaceable part and may be obtained by contacting A. O.
Smith Corporation at 500 Tennessee Waltz Parkway, Ashland City, TN 37015, 1-800-433-2545. In Canada,
contact A. O. Smith Enterprises LTD., P.O. Box, 310 - 768 Erie Street, Stratford, Ontario, Canada N5A 6T3,
1-800-265-8520.
Each automatic flue damper drive assembly is equipped with a "Service Switch", as shown in Figure below.
The "Service Switch" has 2 positions: AUTOMATIC OPERATION and HOLD OPEN DAMPER. For normal
operation the switch should be in the AUTOMATIC OPERATION position.
If there is a problem with the damper the "Service Switch" can be placed in the HOLD OPEN DAMPER
position. When the switch is placed in the HOLD OPEN DAMPER position the damper disc will rotate to
the open position and the heater may be used until vent assembly is repaired or replaced. DO NOT turn the
damper disc manually; damage will occur to the drive assembly if operated manually. Refer to TESTING
DAMPER OPERATION section of this manual for additional information.
FLUE DAMPER

UNCRATING

The heater is shipped with the flue damper already installed. The wiring conduit runs from the thermostat to
the damper drive cover. Before turning unit on, check to make sure the wiring conduit is securely plugged
into damper drive.
Servicing should only be performed by a Qualified Service Technician 9