20
hIGh tEMPErAturE LIMIt ControLs (ECo)
Both the ELECTRONIC CONTROL and SURFACE MOUNT
CONTROL model water heaters are equipped with one or more ECO
(energy cut out) non adjustable high temperature limit control(s). An
ECO is a normally closed switch that opens (activates) on a rise
in temperature. If the ECO switch contacts open (activate) due to
abnormally high water temperatures it will lock-out and disable further
heating element operation. 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(s) can be reset as follows:
surface Mount Control Models
Surface Mount Control models have multiple surface mounted
Thermostat/ECO combination controls. One for each installed heating
element - see the Surface Mount Control wiring diagrams in this manual.
The ECO high temperature limit switch contacts on each control will
open when the tank temperature reaches approximately 200°F/93°C.
When the ECO switch contacts open (activate) voltage to ONE heating
element ONLY is terminated to prevent further heating operation of that
element. Voltage may still be present at other heating elements and
they may still be heating the water.
The ECO is a manual reset switch. Should one or more ECO activate,
the tank temperature must drop below 120°F/49°C before an ECO
can be reset. To manually reset an ECO:
1. Disconnect the power supply to the water heater.
2. Allow the tank temperature to cool below 120°F/49°C.
3. Remove the front control cover from the effected control(s).
4. Press the manual reset button on each of the effected controls.
Once the control(s) has been reset the control cover should be
replaced prior to restoring power to the water heater.
Electronic Control Models
The ECO high temperature limit switch is located inside the
immersion Temperature Probe (two red wires) on ELECTRONIC
CONTROL models. The ECO switch contacts will open when the
water temperature reaches approximately 202°F/94°C. When
the ECO switch contacts open (activate) the electronic control
system locks out and displays a Fault message. Voltage to the
contactor coils and heating elements is terminated to prevent
further heating operation.
Should the ECO activate, 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 ControLs
The water heaters covered in this instruction manual are equipped
with adjustable thermostat controls 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 duration of exposure. The
slower response time of children, the elderly or disabled persons
increases the hazards to them. 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.
Setting the water heater temperatures at 120°F will reduce the risk of
scalds. Some States require settings at specific lower temperatures.
thErMostAt sEttInGs - surfACE Mount ControL
These models have multiple thermostat/ECO combination controls
one for each heating element installed. These thermostats are set
from the factory at 140°F/60°C. Set the thermostat dial at the lowest
setting which produces an acceptable hot water supply. This will
always give the most energy efficient operation.
figure 7.
Table 6. shows the approximate time-to-burn relationship for normal
adult skin.
water
temperature
°f
time for 1st degree
Burn
(Less severe Burns)
time for
Permanent Burns
2nd & 3rd degree
(Most severe Burns)
110
(normal shower temp.)
116
(pain threshold)
116
35 minutes
45 minutes
122
1 minute
5 minutes
131
5 seconds
25 seconds
140
2 seconds
5 seconds
149
1 second
2 seconds
154
instantaneous
1 second
(U.S. Government Memorandum, C.P.S.C., Peter L.
Armstrong, Sept. 15,1978)
table 6.
tEMPErAturE rEGuLAtIon
