Rheem RESG75-40BP, RUSG75-40BP, RMSG75-40BP, RESG75-48BP, SUSG75-40BP Use & Care Manual

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Use & Care Manual

With Installation Instructions for the Installer

Pumped Solar Water
Heating Systems

The purpose of this manual is twofold: one, to
provide the installer with the basic directions 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 troubleshooting of the
water heater. This manual also includes a parts list.

It is very important that all persons who are expected
to install, operate or adjust this water heater read the
instructions carefully so they may understand how to
perform these operations. If you do not understand these
instructions or any terms within it, seek professional
advice.

Any questions regarding the operation, maintenance,
service or warranty of this water heater should be
directed to the seller from whom it was purchased. If
additional information is required, refer to the section on
“If you need service.”

Do not destroy this manual. Please read carefully and
keep in a safe place for future reference.

Recognize this symbol as an indication of

!

Important Safety Information!

California Proposition 65 Warning: This

!

product contains chemicals known to the State of
California to cause cancer, birth defects or other
reproductive harm.

I

S

G

E

N

D

®

AP15326-1 (04/11)

System Model Numbers

PLEASE VISIT OUR WEB SITE FOR NEW PRODUCT UPDATES, ANSWERS TO FREQUENTLY
ASKED QUESTIONS (FAQ) AND USEFUL INFORMATION ABOUT SOLAR WATER HEATING
SYSTEMS.

www.rheem.com

This Solar Water Heating system is for the models listed below:

RSG75-48BP

RUSG75-40BP

RUSG75-48BP

RSG75-40BP

RMSG75-40BP

RMSG75-48BP

RESG75-40BP

RESG75-48BP

SUSG75-40BP

SUSG75-48BP

SUSG75-48BC

SUSG100-64BP

2

Safety Information

!

System Model Numbers . . . . .2

For Your Records . . . . . . . . . .3

Introduction . . . . . . . . . . . . . . . . . 4

Safety Precautions . . . . . . . . . . .5-7

Installing the System

Introduction to Solar . . . . . . . 8

System Description and

Operational Principle . . . . . . . 9

Installation Requirements -

General . . . . . . . . . . . . . . . . . . 9

Installation Requirements -

Specic . . . . . . . . . . . . . . 10-20

Operating the System

Start Up Procedures . . . . . . .21

Three Modes of System

Operation . . . . . . . . . . . . 22-23

Use and Care of the
System

Isolating the Major Components
and Shut Down Procedures . 24

Summer Vacation

Recommendations . . . . . . . . 24

Maintenance and

Troubleshooting . . . . . . . 25-26

System Component Parts 26-27

System Schematics . . . . . 28-31

FOR YOUR RECORDS

Write the model and serial numbers here:

Model Number of Solar System Tank: ____________________________________

Serial Number of Solar System Tank: _____________________________________

Model Number of Collector Panel #1: ____________________________________

Serial Number of Collector Panel #1: _____________________________________

Model Number of Collector Panel #2: ____________________________________

Serial Number of Collector Panel #2: _____________________________________

Model Number of Solar System Pump: ___________________________________

Serial Number of Solar System Pump: ____________________________________

Model Number of Solar System Control: _________________________________

Serial Number of Solar System Control: _________________________________

You can find them on a label on the appliance.
Staple sales slip or cancelled check here.
Proof of the original purchase date is needed to obtain service
under the warranty.

READ THIS MANUAL

Inside you will find many helpful hints on how to use and
maintain your water heater properly. Just a little preventive care
on your part can save you a great deal of time and money over
the life of your water heater.

You’ll find many answers to common problems in the Before
You Call For Service section. If you review our chart of
Troubleshooting Tips first, you may not need to call for service
at all.

READ THE SAFETY INFORMATION

Your safety and the safety of others are very important. There
are many important safety messages in this manual and on your
appliance. Always read and obey all safety messages.

Customer Service

If You Need Service . . . . . . . 32

This is the safety alert symbol. Recognize this symbol as
an indication of Important Safety Information!

!

This symbol alerts you to potential hazards that can kill

or hurt you and others.
All safety messages will follow the safety alert symbol and
either the word “DANGER”, “WARNING”, “CAUTION” or
“NOTICE”.

These words mean:

!

DANGER

that will result in death or serious
injury.

WARNING

could result in death or serious injury

and/or damage to property.

!

CAUTION

may result in minor or moderate
injury.

NOTICE:

specified procedure or maintain
a specific condition.

An imminently hazardous situation

A potentially hazardous situation that

A potentially hazardous situation that

Attention is called to observe a

3

Introduction

!

Thank you for purchasing a solar water heating system. It is
one of the most effective and trouble-free systems available
today. In addition to reducing your water-heating bills, it
will help preserve precious natural resources by using free
energy from the sun.

As with an electric or gas water heater, your new solar water
heating system operates automatically to ensure you will
always have an ample supply of hot water. However, there
are simple steps you can take to increase both its efficiency
and service life.

This manual provides the manufacturers recommended
procedures for solar water-heating systems. The procedures
are essential for correct installation, troubleshooting and
maintenance.

Read each section of this manual thoroughly before
beginning work on the system.

CAUTION: Changes to the design or intended
use of the Solar Water Heating System will void the
manufacturers warranty. Installation,
troubleshooting, and maintenance must be
performed by a qualified technician.

This manual will help you get the most out of your solar

water heating system. Please read it carefully when the
installation is complete, and review it from time to time to
refresh your memory about the service requirements and
safety measures.

The Operation section of the manual contains important
information regarding the system procedures as well as
safety measures pertaining to the system. It is important
that you follow these guidelines to ensure safe, efficient and
trouble-free operation.

While the system requires very little maintenance, there
will be a periodic need for some upkeep. The Maintenance
section outlines those requirements for service, which you
may do yourself, as well as those procedures best performed
by a qualified service technician.

The Troubleshooting section contains steps you can take if
the system is not performing, as it should.

The solar energy system described by this manual, when
properly installed and maintained, meets the minimum
standards established by the Solar Rating and Certification
Corporation (SRCC). This certification does not imply
endorsement or warranty of this product by the SRCC.

The solar energy system described by this manual, when
properly installed and maintained, meets the minimum
standards established by the Florida Solar Energy Center,
in accordance with Section 377.705, Florida Statutes. This

certification does not imply endorsement or warranty of this
product by the Florida Solar Energy Center or the state of
Florida.

The components of the system include a water storage tank,
solar collector panels, expansion tank, pump valves and
fittings.

In locations which are subject to temperatures below 41°F,
a mixture of heat transfer fluid and water circulates through
the solar collector panels. This fluid is heated by the sun,
then circulated through a heat exchange, heating the potable
(drinking) water inside the storage tank. The heat transfer
fluid is a non-toxic, food-grade liquid, which provides freeze
protection for the closed loop heat transfer loop. It is colored
to differentiate the closed system fluid from the potable
water supply.

This circulation of the heat transfer fluid is accomplished by
a pump and sensors. These solar water heaters are referred
to as closed loop systems.

Your hot water is stored in a steel tank lined with porcelain
enamel and thickly insulated to help maintain the water
temperature throughout the day and night.

To ensure your hot water supply is never depleted, the
system is equipped with a backup thermostactic gas valve.
When there may be insufficient solar energy, you are still
assured of all the hot water you will need.

While your system is one of the most efficient available,
there are two simple steps you can take to increase your
water-heating cost savings.

Keep the use of the Backup Heater to a Minimum

You can save the most money on your water-heating bills by
using the backup thermostactic gas valve on your system as
little as possible. If the sun shines brightly between 10 am
and 3 pm, enough heat will normally be generated to keep
the water hot throughout the rest of the day and night.

However, on days when the sky is cloudy or when large
quantities of hot water are being used, we suggest that the
backup thermostactic gas valve be left “ON” overnight to
ensure adequate hot water the next morning.

Try to use Hot Water during Daylight Hours

When possible, schedule heavy hot water use, such as dish
washing, laundry and showers, in the middle of the day. If
hot water usage occurs while the sun is up, the fresh (cold)

water added to the storage tank is heated more quickly.

When water is used late in the day or at night, the fresh
water entering the tank will be heated by the thermostactic
gas valve so hot water is available in the morning.

4

IMPORTANT SAFETY INFORMATION.

!

!

!

READ ALL INSTRUCTIONS BEFORE USING.

DANGER!

WATER TEMPERATURE SETTING

Safety and energy conservation are factors to be considered when selecting the water
temperature setting of a water heater’s gas control. Water temperatures above 125°F can cause
severe burns or death from scalding. Be sure to read and follow the warnings outlined on the
label pictured below. This label is also located on the water heater.

Time/Temperature Relationship in Scalds

!

D A N G E R

HOT

BURN

Water temperature over 125°

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.

Notice: Mixing valves are available for reducing point
of use water temperature by mixing hot and cold water
in branch water lines. Contact a licensed plumber or the
local plumbing authority for further information.

F (52°C)

Water Temperature Time To Produce a Serious Burn

120°F (49°C) More than 5 minutes

125°F (51°C) 11/2 to 2 minutes
130°F (54°C) About 30 seconds
135°F (57°C) About 10 seconds
140°F (60°C) Less than 5 seconds
145°F (63°C) Less than 3 seconds
150°F (66°C) About 11/2 seconds
155°F (68°C) About 1 second

Table courtesy of Shriners Burn Institute

The chart shown above may be used as a guide
in determining the proper water temperature for your
home.

DANGER: Households with small children,
disabled, or elderly persons may require a 120°F
or lower gas control (thermostat) setting to prevent
contact with “HOT” water.

Maximum water temperatures occur just after the
burner has shut off. To find water temperature being
delivered, turn on a hot water faucet and place
a thermometer in the water stream and read the
thermometer.

The temperature of the water in the heater can be
regulated by setting the temperature dial on the
front of the gas control (thermostat). To comply
with safety regulations the gas control(thermostat)
was set at its lowest setting before the water heater

was shipped from the

110°F

100°F

90°F

80°F

45°F

Temperatures are approximate

120°F

130°F

140°F

150°F

160°F

factory.

The illustration at
the left details the
approximate water
temperature
for each mark on
the Gas Control
(Thermostat)
Temperature Dial.

DANGER: Hotter water increases the potential for
Hot Water SCALDS.

5

IMPORTANT SAFETY INFORMATION.

!

!

READ ALL INSTRUCTIONS BEFORE USING.

DANGER!

LIQUEFIED PETROLEUM (LP PROPANE OR BUTANE)
AND NATURAL GAS MODELS

LP and Natural gas have an odorant added to aid in detecting a gas leak. Some people
may not physically be able to smell or recognize this odorant. If you are unsure or
unfamiliar with the smell of LP or natural gas, ask the gas supplier. Other conditions,
such as “odorant fade”, which causes the odorant to diminish in intensity, can also hide or
camouflage a gas leak.

● Water heaters utilizing LP gas are

different from natural gas models. A
natural gas water heater will not function
safely on LP gas and vice versa.

● No attempt should ever be made to

convert the water heater from natural
gas to LP gas. To avoid possible
equipment damage, personal injury or
fire, do not connect the water heater to a
fuel type not in accordance with the unit
data plate. LP for LP units. Natural gas
for natural gas units. These units are not
certified for any other fuel type.

● LP appliances should not be installed

below grade (for example, in a basement)
if such installation is prohibited by
federal, state and/or local laws, rules,
regulations or customs.

● LP gas must be used with great caution.

It is heavier than air and will collect first
in lower areas making it hard to detect at
nose level.

● It is recommended that more than one

method, such as soapy solution, gas
detectors, etc., be used to detect leaks in
gas applications.

DANGER: If a gas leak is present or
suspected:

● Donotattempt to find the cause yourself.

● Donot try to light any appliance.

● Donot touch any electrical switch.

● Donot use any phone in your building.

● Leave the house immediately and make

sure your family and pets leave also.

● Leave the doors open for ventilation

and contact the gas supplier, a qualified
service agency or the fire department.

● Stay away from the house (or building)

until the service call has been made, the
leak is corrected and a qualified agency
has determined the area to be safe.

● Before attempting to light the water

heater, make sure to look and smell for
gas leaks. Use a soapy solution to check
all gas fittings and connections. Bubbling
at a connection indicates a leak that must
be corrected. When smelling to detect a
gas leak, be sure to sniff near the floor
also.

● Gas detectors are recommended in LP

& natural gas applications and their
installation should be in accordance
with the detector manufacturer’s
recommendations and/or local laws,
rules, regulations or customs.

6

!

WARNING!

For your safety, the information in this manual must be followed to minimize the risk of fire or
explosion, electric shock, or to prevent property damage, personal injury, or loss of life.

FOR INSTALLATIONS IN THE STATE OF CALIFORNIA

California Law requires that residential water heaters must be braced, anchored or strapped
to resist falling or horizontal displacement due to earthquake motions. For residential water
heaters up to 52 gallon capacity, a brochure with generic earthquake bracing instructions can be
obtained from: Office of the State Architect, 1102 Q Street, Suite 5100, Sacramento, CA 95814
or you may call 916-445-8100 or ask a water heater dealer.

However, applicable local codes shall govern installation. For residential water heaters
of a capacity greater than 52 gallons, consult the local building jurisdiction for acceptable
bracing procedures.

SAFETY PRECAUTIONS

Have the installer show you the location of the circuit breaker and how to shut it off if
necessary. Turn off the circuit breaker if the water heater has been subjected to overheating,
fire, flood, physical damage or if the ECO fails to shut off.

● Read this manual entirely before installing

or operating the water heater.

● Use this appliance only for its intended

purpose as described in this Use and Care
Manual.

● Be sure your appliance is properly installed

in accordance with local codes and the
provided installation instructions.

● Do not attempt to repair or replace any part

of your water heater unless it is specifically
recommended in this manual. All other
servicing should be referred to a qualified
technician.

READ AND FOLLOW THIS SAFETY INFORMATION
CAREFULLY.

SAVE THESE INSTRUCTIONS

7

Installing the System

Preface

Let us rst offer two words of grateful
appreciation.Thank You! We sincerely
appreciate your business. We also wish to
say thank you for "going solar". Solar water
heating systems help to reduce our nation’s
dependence on polluting fossil fuels,
minimize the greenhouse gas emissions
associated with conventional water heating
and, very importantly, lower your monthly
utility costs.

Your solar water heating system has been
designed to meet exacting SRCC OG-300
certication requirements. The components
found in your system have been selected
for their proven reliability, longevity and
performance in your specic region of the
country.

Introduction to Solar Water Heating Systems

Solar water heating systems are climate
and site specic appliances. Different types
of solar systems are installed around the
world in accordance with regional weather
and water quality conditions. System
performance varies as a function of the
household hot water load, including daily
showers, laundry and kitchen uses, average
ground water and ambient air temperatures,
the home’s roof pitch and orientation, and,
of course, the seasonal intensity of solar
radiation. These variables, some of which
change from home to home on the same
neighborhood street, will determine how
much energy and money your system will
save on an annual basis.

Your solar system is known as a "forced
circulation" system because it utilizes a
mechanical pump to efciently circulate
the Dow Chemical Dowfrost HD propylene
glycol heat transfer uid (HTF) throughout
the system. The HTF protects the collector
piping from freezing and inhibits scaling
deposits that can reduce performance in
"open-loop" systems utilizing potable
water as the HTF. Proper application and
maintenance of the HTF can protect your
solar water heating system to minus 60°
Fahrenheit.

This manual is intended as a basic solar
water heating primer. Our goal is to
familiarize you with the proper installation,
operation, and maintenance of your solar
system. This system is required to be
installed by properly licensed solar or
plumbing contractors in accordance with
SRCC Standard OG-300 and all applicable
national, state and local codes, ordinances
and regulations governing solar water
heating installations, as well as good trade
practices. Failure to follow the procedures
and practices described in this manual
can void the manufacturer's warranty for
specic component parts.

This manual covers installations utilizing
two solar collectors with a single solar
storage tank and also two tank systems
that include a solar storage tank and a
conventional water heater. For simplicity,
the singular form will be used throughout
this manual when referring to all of these
components and system permutations.
Frequent reference is made throughout
this manual to specic component parts.
The placement of each component can be
seen in system schematic gures 16, 17,
18 & 19. A description of each component
and its function is found in the System
Component Parts section

8

System Decription and Operational Principle

The key components in the solar water heating
system include the solar collector, solar
storage tank with integral heat exchanger,
circulation pump, differential thermostat,
expansion tank, pressure gauge, mixing valve
and the non-toxic propylene glycol heat
transfer uid (HTF).

The solar collector is the heart of the system.
Simply stated, when the sun is shinning, heat
energy is absorbed by the solar collector’s all
copper absorber plate and tranferred to the
HTF circulating through the solar collector.
The system pump efciently circulates this
heated uid through the collector piping and
integral tank heat exchanger. As the HTF
passes through the heat exchanger the heat in
the uid is transferred by conduction to the
potable water in your solar storage tank. As
this process is continuously repeated during
the average sunny day the temperature in your
solar storage tank rises.

When the solar collector absorber plate is
approximately sixteen degrees hotter than the
temperature in the bottom of your solar storage
tank, the controller will turn the circulating
pump on. When the temperature difference has
been reduced to eight degrees, the controller
automatically turns the pump off.

Both single and double tank systems are
designed to provide three separate modes
of system operation. The system will, (1)
accommodate 100% solar operation, (2) serve
as a preheater to your solar storage tank or

back-up water heater, or (3) bypass the solar
collector and run 100% on utility power.
Section Six provides instructions for setting
the system for automatic operation in each of
these three modes.

The Dowfrost HD HTF protects your solar
system against freezing. Dowfrost HD
can provide reliable freeze protection at
temperatures as low as minus 60° Fahrenheit
if properly applied and maintained. Use of
uninhibited propylene glycol, plain water or a
concentration of these two uids as the HTF in
this system is strictly prohibited.

Propylene glycol can degrade over time.
The process of degradation is accelerated in
presence of oxygen and/or heat. We strongly
encourage you to establish a preventative
maintenance schedule with your installation
contractor. The HTF pH level must be
maintained between 8 and 10 in order to
prevent glycol oxidation and corrosion of the
collector piping. Manufacturer’s collector
warranty specically excludes freeze damage
for any reason and absorber plate damage
resulting from the oxidation of the propylene
glycol HTF.

In order to completely protect the integrity of
the solar collector and piping, the system is
designed to be drained manually if subject to
extended periods of disuse or persistent hard
freeze conditions below minus 60° Fahrenheit.
(See Summer Vacation Recommendations and
Procedures Section).

Installation Requirements - General

The contractor shall obtain all required permits
and approvals.

The installation shall conform to all federal,
state and local regulations, codes, ordinances
and standards governing solar water heating
system installations, and the contractor shall
adhere to sound building safety and trade
practices. Special consideration must be
given to building code requirements for the
penetration of structural members and re
rated assemblies.

The solar collector must be located in a
structurally sound area of the roof that will be
unshaded for the majority of the day all year
round. Adjacent buildings and trees should
be checked for possible winter shading. An
instrument such as the Pathnder can be used
for solar site analysis.

Before the installation the contractor shall
inspect the condition of the roof and notify the
homeowner of any existing roof damage or
necessary repairs.

9

Installing the System

Installation Requirements - Specific

The homeowner and contractor shall conrm the
location of all roof and ground mounted components
in advance of the installation.

Collector Orientation

The performance of solar water heating systems
in the Northern Hemisphere is optimized when
the collector is mounted facing True South.
Performance, however, suffers very little when the
collector is oriented no more than 45° East or West
of True South. The collector should be unshaded
by any permanent obstacle between 9:00 a.m. and
3:00 p.m. on any day of the year.

Figure 2 - Side Pitch Mounting

The solar collectors in a two collector staggered
mount installation must be spaced far enough apart
to prevent winter shading. Table 1 shows the correct
spacing between collectors to prevent shading on
December 21, when the sun is at its lowest angle.

Figure 1 - Reverse Pitch Mounting

Collector Tilt

Optimal annual efciency is achieved by tilting the
solar collector at an angle that equals your latitude
plus an additional 10°. This tilt angle favors the
lower winter sun when collector performance is at
it’s lowest and minimizes overheating during the
hottest summer months.

Figure 3 - Staggered Mount Collector Spacing

TABLE 1

LATITUDE 25°N 30°N 35°N 40°N 45°N 50°N

COLL. TILT 35° 40° 45° 50° 55° 60°

A B A B A B A B A B A B

FLAT 29 96 33 113 37 145 41 145 44 145 48 145
5° 1/12 25 83 29 93 33 113 37 132 41 133 44 141
9° 2/12 22 74 26 82 30 77 34 110 38 115 41 118

14° 3/12 17 66 22 72 26 82 30 92 34 95 38 98

18° 4/12 14 61 18 66 22 74 26 82 30 85 34 87
ROOF 23° 5/12 10 58 14 60 18 66 22 72 26 74 30 77
PITCH 27° 6/12 7 58 11 58 15 61 19 66 23 68 27 70

30° 7/12 4 58 8 58 13 58 17 62 21 65 25 66

34° 8/12 0 58 5 58 9 58 13 58 17 60 22 62

37° 9/12 0 58 3 58 7 58 11 58 15 58 19 58

40° 10/12 0 58 0 58 4 58 8 58 13 58 17 58

43° 11/12 0 58 0 58 2 58 6 58 10 58 14 58

45° 12/12 0 58 0 58 0 58 4 58 8 58 13 58

DIMENSIONS A AND B ARE DESIGNATED IN INCHES

10