A.O. Smith BTR 151 THRU 201/A Water Heater User Manual


 
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set for 120°
to 180°F water temperature, but 120°F is the
recommended starting point. It is suggested the dial be placed
on the lowest setting which produces an acceptable hot water
supply. This will always give the most energy efficient operation.
The temperature control has a 4°F (2°C) fixed differential.
PREVENTIVE MAINTENANCE
CHECK THE IGNITOR ASSEMBLY
At least once a year, check the ignitor assembly, see Figure 11,
and the main burner, see Figure 12, for proper operation. Refer
to the following ignitor assembly and main burner sections.
IGNITOR ASSEMBLY
For access to ignitor assembly, unfasten two screws to burner
cover and remove. Locate the burner with the ignitor assembly
and remove screw holding burner to manifold. Slide burner out
to access ignitor assembly.
Servicing of the ignitor assembly includes keeping the ignitor
free of lint, scale or any other foreign debris.
FIGURE 11
MAIN BURNER
The main burner, see Figure 12, should display the following
characteristics:
Cause rapid ignition and carry across entire burner.
Give reasonably quiet operation during ignition, burning, and
extinction.
Cause no excessive lifting of flame from burner ports.
FIGURE 12
If the preceding burner characteristics are not evident, check for
accumulation of lint, scale or other foreign debris that restricts or
blocks the air openings to the burner or heater.
WATER TEMPERATURE CONTROL
DANGER
THIS WATER HEATER IS EQUIPPED WITH AN ADJUSTABLE
THERMOSTAT TO CONTROL WATER TEMPERATURE. HOT
WATER TEMPERATURES REQUIRED FOR AUTOMATIC
DISHWASHER AND LAUNDRY USE CAN CAUSE SCALD BURNS
RESULTING IN SERIOUS PERSONAL INJURY AND/OR DEATH.
THE TEMPERATURE AT WHICH INJURY OCCURS VARIES WITH
THE PERSON'S AGE AND TIME OF EXPOSURE. THE SLOWER
RESPONSE TIME OF CHILDREN, AGED OR DISABLED PERSONS
INCREASES THE HAZARDS TO THEM. NEVER ALLOW SMALL
CHILDREN TO USE A HOT WATER TAP, OR TO DRAW THEIR
OWN BATH WATER. NEVER LEAVE A CHILD OR DISABLED
PERSON UNATTENDED IN A BATHTUB OR SHOWER.
THE WATER HEATER SHOULD BE LOCATED IN AN AREA
WHERE THE GENERAL PUBLIC DOES NOT HAVE ACCESS TO
SET TEMPERATURES.
SETTING THE WATER HEATER TEMPERATURE AT 120°F (49°C)
WILL REDUCE THE RISK OF SCALDS. Some states or provinces
require settings at specific lower temperatures.
Below you will find listed the approximate time-to-burn
relationship for normal adult skin. Short repeated heating cycles
caused by small hot water uses can cause temperatures at the
point of use to exceed the thermostat setting by up to 20°F (11°C).
If you experience this type of use, you should consider using
lower temperature settings to reduce scald hazards.
Temperature Time to Produce 2nd & 3rd
Setting Degree Burns on Adult Skin
185°F Nearly instantaneous
180°F Nearly instantaneous
170°F Nearly instantaneous
160°F About 1/2 second
150°F About 1-1/2 seconds
140°F Less than 5 seconds
130°F About 30 seconds
120°F More than 5 minutes
Valves for reducing point-of-use temperature by mixing cold and
hot water are available. Also available are inexpensive devices
that attach to faucets to limit hot water temperatures.
Contact a
licensed plumber or the local plumbing authority.
The water temperature is controlled by a thermostat, see Figure
3, which has two sensing elements. One sensor is located
near the top of the tank and the other is near the center. The
thermostat is set in the lowest position before the heater leaves
the factory.
The thermostat temperature dial, see Figure 3, is accessible by
removing the control cover. The dial is adjustable and may be