Operation; Safety Precautions - Rheem Commercial Point-of-Use Electric Water Heater Use & Care Manual

A. Do turn off power to water heater if it has been subjected to over
heating, fire, flood or physical damage.
B. Do Not turn on water heater unless it is filled with water.
C. Do Not turn on water heater if cold water supply shut-off valve is
closed.
D. If there is any difficulty in understanding or following the OPERATION
or MAINTENANCE instructions, it is recommended that a qualified
person or serviceman perform the work.
1. WATER TEMPERATURE SETTING — The temperature of the water in
the water heater can be regulated by setting the temperature dial of the
adjustable surface mounted thermostat located behind the jacket access
panel. To comply with safety regulations the thermostat is factory set at
120° F or less where local codes require.
Reset Button
Thermostat Protective
Cover
CAUTION!! — Hotter water increases the risk of SCALDING!
This illustration shows the temperature adjustment dial used for setting the
water temperature. Refer to Section 1 - Water Temperature Setting, above, for
more details and safety instructions regarding water temperature setting.
Figure 4. — Thermostat and Protective Cover.
Safety and energy conservation are factors to be considered when
selecting the water temperature setting of the water heater's thermostat.
The lower the temperature setting the greater the savings in energy and
operating costs.
!
DANGER
There is a Hot Water SCALD Potential if the thermostat is set too high.
NOTE: When this water heater is supplying general purpose hot
water requirements for use by individuals, a thermostatically
controlled mixing valve for reducing point of use water
temperature is recommended to reduce the risk of scald injury.
Contact a licensed plumber or the local plumbing authority for
further information.

SAFETY PRECAUTIONS

Thermostat Dial
Pointer
110
170
120
160
150 140 130
TURN OFF
POWER
BEFORE
SERVICING

Operation

!
CAUTION
Hydrogen gas can be produced in a hot water system served by this
water heater that has not been used for a long period of time
(generally two weeks or more). HYDROGEN GAS IS EXTREMELY
FLAMMABLE!! To dissipate such gas and to reduce risk of injury, it is
recommended that the hot water faucet be opened for several
minutes at the kitchen sink before using any electrical appliance
connected to the hot water system. If hydrogen is present, there will
probably be an unusual sound such as air escaping through the pipe
as the water begins to flow. Do not smoke or use an open flame near
the faucet at the time it is open.
TIME / TEMPERATURE RELATIONSHIPS IN SCALDS
Temperature
120° F
125° F
130° F
135° F
140° F
145° F
150° F
155° F
!
DANGER
Make certain power to water heater is OFF before removing jacket
access panel FOR ANY REASON.
If adjustment is necessary, turn off power to water heater, remove
jacket access panel and insulation exposing thermostat. The thermostat
protective cover should not be removed . Set thermostat dial pointer,
with a small screwdriver, to desired temperature. (Refer to Fig. 4.)
Replace insulation and jacket access panel. Turn on power to water
heater.
2. SAFETY CONTROLS — The water heater is equipped with a
combination Thermostat and Temperature Limiting Control (ECO) that is
located above the heating element in contact with the tank surface. If for
any reason the water temperature becomes excessively high, the
Temperature Limiting Control (ECO) breaks the power circuit to the
heating element. Once the control opens, it must be reset manually.
!
CAUTION
The cause of the High Temperature Condition must be investigated by
qualified service personnel and corrective action taken before placing
the water heater in service again.
To reset Temperature Limiting Control, turn off power to water heater,
remove jacket access panel and insulation. The thermostat protective
6
Time to Produce Serious Burn
More than 5 minutes
1 1 / to 2 minutes
2
About 30 seconds
About 10 seconds
Less than 5 seconds
Less than 3 seconds
About 1 1 / seconds
2
About 1 second
Table courtesy of Shriners Burn Institute