Rheem Commercial Point-of-Use Electric Water Heater Use & Care Manual
Commercial P oint-of-Use Electric W ater Heater
USE & CARE M AN UAL
WITH INSTALLATION INSTRUCTIONS FOR THE CONTRA CTOR
The purpose of this manual is twofold: one, for
the installing contractor, to provide requirements
and recommendations for the proper installation
and adjustment of the water heater; and two, for
the owner-operator, to explain the features, operation, safety precautions, maintenance and
trouble shooting of the water heater. This manual also includes replacement parts information.
It is imperative that all persons who are expected to install, operate or adjust this water heater
read the instructions carefully so that they may
understand how to do so.
®
LISTED
786H
Do Not Destroy this Manual. Please read carefully and
!
keep in a safe place for Future Reference.
NOTICE: This water heater is designed for use in a commercial application and the installation and maintenance of it
should be performed by qualified, licensed service personnel. If the foregoing assumption is not appropriate, then we
!
recommend that you obtain and retain our Residential Use & Care Manual.
CALIFORNIA PROPOSITION 65 WARNING: This product contains chemicals known to the State of California to cause
cancer, birth defects or other reproductive harm.
!
Printed in USA
Recognize this symbol as an Indication of Important
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Safety Information!
AP12129-4 (01/05)
General Safety Precautions
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Be sure to read and understand the entire Use & Care Manual before attempting to install or operate this water heater. It may save you time and cost.
Pay particular attention to the General Safety Precautions. Failure to follow these warnings could result in serious bodily injury or death. Should you
have problems understanding the instructions in this manual, or have any questions, STOP, and get help from a qualified installer, service technician,
or the local electric utility.
To meet commercial water use needs, the thermostat on this water
heater is adjustable to deliver water up to 170°F. However, water
temperatures over 125°F. can cause severe burns instantly or
death from scalds. This is the preferred starting point for setting
the control for supplying general purpose hot water.
delivered, turn on a hot water faucet and place a thermometer in
the hot water stream and read the thermometer.
The following chart details the relationship of water temperature and time with regard to scald injury and may be
used as a guide in determining the safest water temperature for your applications.
shut off the elements. To find the hot water temperature being
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DANGER
The temperature of the water in the heater can be regulated
by adjusting the thermostat. To comply with safety regula-
HOT
tions the thermostat was set at the factory to a setting corresponding to 120°F.
TIME / TEMPERATURE RELATIONSHIPS IN SCALDS
Temperature Time to Produce Serious Burn
120° F More than 5 minutes
1
125° F 1
130° F About 30 seconds
135° F About 10 seconds
140° F Less than 5 seconds
145° F Less than 3 seconds
150° F About 1
155° F About 1 second
/2to 2 minutes
1
/2seconds
Table courtesy of Shriners Burn Institute
BURN
Water temperature over 125°F can
cause severe burns instantly or
death from scalds.
Children, disabled and elderly are
at highest risk of being scalded.
See instruction manual before
setting temperature at water
heater.
Feel water before bathing or
showering.
Temperature limiting valves are
available, see manual.
Safety and energy conservation are factors to be considered when
setting the water temperature on the thermostat. The most energy
efficient operation will result when the temperature setting is the
lowest that satisfies the needs consistent with the application.
Maximum water temperatures occur just after the thermostat has
The illustration above shows the temperature adjustment
dial used for setting the water temperature. Refer to Operation section of this manual for detailed instructions in how
to adjust the thermostat(s).
!
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.
Reset Button
Thermostat Protective
Cover
DANGER
T
E
S
E
R
170
160
TURN OFF
POWER
BEFORE
SERVICING
R
E
S
E
T
Thermostat Dial
Pointer
110
120
130140150
2
Introduction
The location chosen for the water heater must take into consideration the
following:
LOCAL INSTALLATION REGULATIONS
This water heater must be installed in accordance with these instructions, local
codes, utility company requirements or, in the absence of local codes, the latest
lower floors of the structure. Where such areas cannot be avoided, it is
recommended that a suitable catch pan, adequately drained, be installed
under the water heater.
NOTE: Auxiliary catch pan installation MUST conform to local codes.
edition of the National Electrical Code. It is available from some local libraries or
can be purchased from the National Fire Prevention Association, Batterymarch
Park, Quincy, MA 02269 as booklet ANSI/NFPA 70.
LOCATION
This water heater is designed to meet a wide range of applications. It fulfills a
demand for a small water heater that can be installed in a limited space such as
under counter tops, in cabinets or in a closet. Locate the water heater in a clean
dry area as near as practical to hot water fixtures, or close to the hot water
faucet most frequently used. Place the water heater in such a manner that the
thermostat and element access panels can be removed to permit inspection
and servicing such as removal of elements or checking controls. The water
A — Diameter of water
heater plus 2" min.
B — Maximum 2"
heater and water lines should be protected from freezing temperatures. Do not
install the water heater in outdoor, unprotected areas.
CAUTION
!
The water heater should not be located in an area where leakage of the
Figure 1. — Auxiliary Catch Pan
Catch Pan Kits are available from the distributor or store where the water
heater was purchased
tank or connections will result in damage to the area adjacent to it or to
B
A
To open drain, line
should be at least
ID and pitched for
proper drainage.
3
/4"
Installation
1. INSPECT SHIPMENT — Inspect the water heater for possible damage.
Check the markings on the rating plate of the water heater to be certain the
power supply corresponds to that for which the water heater is equipped.
2. THERMAL EXPANSION — Determine if a check valve exists in the
inlet water line. It may have been installed in the cold water line as a
separate back flow preventer, or it may be part of a pressure reducing
valve, water meter or water softener. A check valve located in the cold
water inlet line can cause what is referred to as a ”closed water
system”. A cold water inlet line with no check valve or back flow
prevention device is referred to as an ”open” water system.
As water is heated, it expands in volume and creates an increase
in the pressure within the water system. This action is referred
to as ”thermal expansion”. In an ”open” water system, expanding
water which exceeds the capacity of the water heater flows back
into the city main where the pressure is easily dissipated.
A ”closed water system”, however, prevents the expanding
water from flowing back into the main supply line, and the result
of ”thermal expansion” can create a rapid, and dangerous pres-
sure increase in the water heater and system piping. This rapid
pressure increase can quickly reach the safety setting of the relief valve, causing it to operate during each heating cycle. Thermal expansion, and the resulting rapid, and repeated expansion
and contraction of components in the water heater and piping
system can cause premature failure of the relief valve, and possibly the heater itself.Replacing the relief valve will not correct
the problem!
The suggested method of controlling thermal expansion is to install
an expansion tank in the cold water line between the water heater and
the check valve. The expansion tank is designed with an air cushion built in that compresses as the system pressure increases,
thereby relieving the over pressure condition and eliminating the repeated operation of the relief valve. Other methods of controlling thermal expansion are also available. Contact your installing contractor,
water supplier, or plumbing inspector for additional information regarding this subject.
IMPORTANT!! Do not apply heat to the hot or cold water supply fitting. If
sweat connections are used, sweat tubing to adapter before fitting
adapter to cold water inlet of heater. Any heat applied to the hot or cold
water supply fittings will permanently damage them.
3. WATER SUPPLY CONNECTIONS — Refer to Fig. 2 or 3 for suggested
typical installation. The installation of unions or flexible copper connectors
on the water connections is recommended so that the water heater may be
easily disconnected for servicing if necessary. Connect cold water supply
line to 3/4” pipe connection near the bottom of water heater. (Refer to
Figure 2.) Install a shut-off valve and a drain valve (not supplied) in the cold
water line near the water heater (Refer to Fig. 2.). Connect hot water line to
3/4” pipe connection marked HOT on the side near the top of the water
heater. On the some models, the hot and cold water connections are 1/2”
pipe connections and are located on top of the heater. (Refer to Figure 3.)
A drain valve is supplied on these models. Local codes may require an
Anti-Syphon device on the water inlet of a side connect water heater.
3
Installation
Recommended
Heat Trap
6" Min.
Hot Water
Outlet to Fixtures
Temperature & Pressure
Relief Valve
To Cold Water
Supply
Relief Valve
Discharge
Line to suitable
open drain
Shut-Off
Valve
Drain Valve
(Not Supplied)
Air Gap
6"
Auxiliary
Catch Pan
Jacket Access
Panel
Union
Opening for
1/2" or 3/4"
Electrical Fitting
(Use only Copper
Conductors)
Vacuum Relief Valve
Anode
If required, install per local codes
(Not Supplied)
and valve manufacturer’s
instructions.
Shut-Off Valve
Cold Water Supply
Relief Valve
Discharge Line
Suitable Open Drain
*Drain valve is located below and to right of Jacket Access Panel and is not
6"
visible in this view.
Unions
Hot Water Outlet
(To Fixtures)
Auxiliary Catch Pan Drain Line
Temperature
Pressure
Relief Valve
Jacket Access Panel
Auxiliary Catch Pan
Power Supply Cord
21/2gal. models only
Drain valve*
Figure 2. — Typical Side Connect Installation
4. RELIEF VALVE — A new combination pressure and temperature relief
valve, complying with the Standard for Relief Valves and Automatic Gas
Shutoff Devices for Hot Water Supply Systems, ANSI Z21.22, must be
installed in the opening provided and marked for the purpose on the
water heater. (Refer to Fig. 2 or 3.) No valve of any type should be
installed between the relief valve and the tank. Local codes shall govern
the installation of relief valves.
Figure 3. — Typical Under Counter Top Connect Installation
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Tank MUST BE full of water before power is turned on. Heating
element(s) WlLL BE DAMAGED if energized for even a short time while
tank is dry. The water heater’s warranty does not cover damage or
failure resulting from operation with an empty or partially empty tank.
(Reference is made to the limited warranty for complete terms and
conditions.)
The pressure rating of the relief valve must not exceed 150 psi, the
maximum working pressure of the water heater as marked on the rating
plate. The BTUH Rating of the relief valve must not be less than the
input rating of the water heater as indicated on the rating label located on
the front of the heater (1 watt = 3.412 BTUH).
6. ELECTRICAL CONNECTIONS — The voltage requirements and wattage
load for all heaters is specified on the rating plate. Table 1 recommends
minimum branch circuit sizing based on the National Electrical Code. All
wiring must conform to local codes or latest edition of National Electrical
Code ANSI/NFPA 70.
Connect the outlet of the relief valve to a suitable open drain so that the
discharge water cannot contact live electrical parts and to eliminate
potential water damage. Piping used should be of a type approved for hot
Some models are supplied with a plug connected power supply cord for use
only in 120 VAC applications. The cord must be connected to a properly
water distribution. The discharge line must be no smaller than the outlet of
the valve and must pitch downward from the valve to allow complete
drainage (by gravity) of the relief valve and discharge line. The end of the
discharge line should not be threaded or concealed and should be
Water Heater
Wattage
protected from freezing. No valve of any type, restriction or reducer
coupling should be installed in the discharge line.
5. TO FILL WATER HEATER — Make certain drain valve is completely
closed. Open shut-off valve in cold water supply line. Open each hot water
faucet slowly to allow air to vent from the water heater and piping. A steady
flow of water from the hot water faucet(s) indicates a full water heater.
WARNING
Recommended Over
Total
1440 15 --- --- --- --- 14 --- --- --- --1500 20 15 15 15 15 12 14 14 14 14
2000 25 15 15 15 15 10 14 14 14 14
2500 30 15 15 15 15 10 14 14 14 14
3000 35 20 20 15 15 8 12 12 14 14
4500 --- 30 25 25 15 --- 10 10 10 14
6000 --- 40 35 30 20 --- 8 8 10 12
Current Protection Copper Wire Size -
(Fuse or Circuit Breaker) AWG Based on N.E.C.
Amperage Rating Table 310-16 (75°C.)
120V 208V 240V 277V 480V 120V 208V 240V 277V 480V
Table 1. — Branch Circuit Sizing and Wire Size
Guide Based on N.E.C. ANSI / NFPA 70
4
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