38
Valves for reducing the point-of-use temperature by mixing cold and
hot water are available. Also available are inexpensi ve devices that
attach to faucets to limit hot water temperatures. Contact a licensed
plumber or the local plumbing auth ority.
The table be low shows the approximate time-to-burn relationship for
nor mal ad ult sk in. Sho rt re peat ed hea tin g cycl es cau sed by sm all ho t wate r
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 hazar ds.
In all cases, the following bur n table must be used. It’s appearance
may be altered to comply wit h each manual’s style, but the c ontent
must remain unchanged. NOTE: If the manual is to be used outside
of the United States, metric equiva lents (Celsius) must be added to
the table.

Table 11

Water Temperature
°F (°C)
Time for 1st Degree Burn
(Less Severe Burns)
Time for Permanent Burns
2nd & 3rd Degree
(Most Severe Burns)
110 (43.3) (normal shower temp.)
116 (46.7) (pain threshold)
116 (46.7) 35 minutes 45 minutes
122 (50) 1 minute 5 minutes
131 (55) 5 seconds 25 seconds
140 (60) 2 seconds 5 seconds
149 (65) 1 second 2 seconds
154 (67.8) instantaneous 1 second
(U.S. Government Memorandum, C.P.S.C., Peter L. Armstrong, Sept. 15, 1978)
HI LIMIT SWITCH (ECO)
This water heater is equipped wit h an ECO (energy cut out) non
adjustable high temperature limit switch. The ECO is a normally
closed switc h that opens (activates) o n a r ise in temperature. The
ECO is loc ated inside th e Temperature Probe (two red wires). The
ECO switch contacts will open when the water temperature reaches
app roxi mat ely 202° F (94° C) and clos e at app rox imat ely 140°F (49° C).
If the ECO acti vates (contacts open) due to abnormally high water
temperatures in the storage tank the control system will immediately
de-energize the 24 VAC G as Control Valve and end the current
heating cycle. T he cont rol system will lock out disabling further
heating operation. The contr ol system will display the Energy Cut
Out (ECO) Fault message on the LCD scree n. It is important that
a Qualied Ser vice Technician be contac ted to determine the
reason for the ECO activation before resetting the ECO. Once the
reason has been determined and co rrected the ECO c an be reset
as follows:
Should the ECO ac tivate, the water temper ature must drop below
140°F (49°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 contro l system.
Contact your dealer or servicer if continued high limit switch operation
occurs.
It is recommended t hat lower water temperatures b e used to avoid
the risk of scalding. It is further reco mmended, in all cases, that the
water temperatures be set for the lowest temperature which satises
your hot water needs. This will also provide the most energy efcient
operation of the water heater.
HOT WATER CAN SCALD: Water heaters are intended to produce
hot water. Water h eated to a temperature which will satisfy space
heating, clothes washing, dish washing, and other sanitizing needs
can scald and permanently injure you upon contact. Some people
are more likely to be p ermanently injured by hot water than others.
These include the elderly, children, the inrm, or physically/mentally
handicapped. If anyone using hot water from this heater ts into one of
these groups or if there is a local code or state law requiring a certain
temperature water at the hot water tap, then you must take special
precautions. In addition to using the lowest possible temperature
setting that satises your hot water needs, a means such as a mixing
valve, should be used at the hot water taps used by these people or
at the water heater. Mixing valve s are available at plumbing sup ply
or hardware stores. Follow manufacturer’s instructions for installation
of the valves. Before changing the factory setting on the thermostat,
read the Temperature Regulation section in this m anual.
Never allow small children to use a hot water tap, or to draw their own
bath water. Never leave a child or handic apped person unattended
in a bathtub or shower.
SETTING THE WATER HEATER TEM PERATURE AT 120°F/49°C
WILL REDUCE THE RISK OF SCALDS. Some states require settings
at specic lower temperatures.
The water temperature is controlled using the Temperature Control on
the D ispl ay at th e fro nt of th e unit (See “F igur e 1B: 50 GALLO N UNI T”
& “Fi gure 1C: 75 GA LLON UNIT ”). Th is co ntro l util ize s a temp erat ure
probe to determine the tank temperature. The tempe rature probe is
located behind the heater’s front disp lay.
The te mpe ratu re may be adju ste d from 90°F/ 32° C to 160 °F/71 °C. Th e
temperature was preset to 120°F/49°C before the heater was shipped
from the factory. It is recommended that lower water temperature be
used to avoid the r isk of scalding. It is further recomme nded, in all
cases, that the water temperature be set for the lowest temperature
which satises your hot water needs. This will also provide the most
energy efci ent operation of the wa ter heater and minimize sc ale
formation.
TEMPERATURE REGULATION