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HIGH TEMPERATURE LIMIT CONTROL (ECO)
This water heater is equipped with an ECO (energy cut out) non
adjustable high temperature limit switch. The ECO is a normally closed
switch that opens (activates) on a rise in temperature.
The ECO is located inside the Temperature Probe (two red wires).
See Figure 1B (page 10) and Figure 1C (page 11). The ECO switch
contacts will open when the water temperature reaches approximately
202°F (94°C) and close at approximately 140°F (60°C).
If the ECO activates (contacts open) due to abnormally high water
temperatures in the storage tank the control system will immediately
de-energize the 24-volt gas valve and end the current heating cycle.
The control system will "lock out" disabling further heating operation.
The control system will display the "Energy Cut Out (ECO)" Fault
message on the LCD screen. It is important that a Qualified Service
Agent be contacted to determine the reason for the ECO activation
before resetting the ECO. Once the reason has been determined and
corrected the ECO can be reset as follows:
If the ECO activates, the water temperature must drop below 140°F
(60°C) before the control system can be reset. Once the water
temperature has cooled below this point the power supply to the water
heater must be turned off and on again to reset the control system.
THERMOSTAT CONTROL
Hot water temperatures required for automatic dishwasher and laundry
use can cause scald burns resulting in serious personal injury and/
or death. Table 17 on page 40 shows the approximate time-to-burn
relationship for normal adult skin.
The temperature at which injury occurs varies with the person's age
and duration of exposure. The slower response time of children, the
elderly or disabled persons increases the hazards to them. If anyone
using hot water provided by the water heater being installed fits into
one of these groups or if there is a local code or state law requiring a
certain water temperature at the point of use, then special precautions
must be taken.
In addition to using the lowest possible temperature setting that
satisfies the demand of the application a mixing valve can be installed
at the water heater or at the hot water taps to further reduce system
water temperature. See Figure 9 on page 20.
Never allow small children to use a hot water tap or 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.
TEMPERATURE REGULATION
Water temperature over 125°F (52°C)
can cause severe burns instantly
resulting in severe injury or death.
Children, the elderly and the
physically or mentally disabled are at
highest risk for scald injury.
Feel water before bathing or
showering.
Temperature limiting devices such as
mixing valves must be installed
when required by codes and to
ensure safe temperatures at fixtures.
Setting the Operating Set Point at 120°F (49°C) will reduce the risk of
scalds. Some States require settings at specific lower temperatures.
Table17. Time/Temperature to Burn
Water Temperature
Time for 1st Degree Burn
°F (°C)
(Less Severe Burns)
110 (43)
(normal shower temp.)
116 (47)
(pain threshold)
116 (47)
122 (50)
131 (55)
140 (60)
149 (65)
154 (68)
(U.S. Government Memorandum, C.P.S.C., Peter L. Armstrong, Sept. 15, 1978)
The water heaters covered in this manual are equipped with an
electronic control system to regulate water temperature inside
the storage tank. The control system senses temperature from a
factory installed temperature probe in the top of the storage tank.
See Figure 1B (page 10) and Figure 1C (page 11) for location.
The "Operating Set Point" is adjusted to regulate water
temperature inside the storage tank. This is an adjustable user
setting in the control system's "Temperatures Menu." This and
all control system menus are accessed through the UIM (user
interface module) located on the front of the water heater, see
Figure 41 on page 41.
The Operating Set Point is adjustable from 90°F (32°C) to 181°F
(83°C). The factory setting is 120°F (49°C). See Operating Set
Point and Differential Adjustment on page 44 for instructions on
how to adjust the Operating Set Point and other user settings.
Set the Operating Set Point at the lowest setting that produces
an acceptable hot water supply. This will always provide the most
energy efficient operation.
HIGH TEMPERATURE APPLICATIONS
Higher operating temperatures cause more wear on all water
heaters and will decrease the life span of the water heater.
Consider installing a small booster water heater for high
temperature applications, such as commercial dishwashers, to
raise the outlet temperature from the larger primary water heater
to the desired point of use temperature.
Contact your local distributor or call the technical support phone
number listed on the back cover of this manual for further
technical assistance.
Operating Set Point
Status: Heating
MENU
Figure 39. Tank Temperature Set point
40
Time for Permanent
Burns
2nd & 3rd Degree
(Most Severe Burns)
35 minutes
45 minutes
1 minute
5 minutes
5 seconds
25 seconds
2 seconds
5 seconds
1 second
2 seconds
instantaneous
1 second
120°F
OFF
O
GAS
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HELP
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