SunEarth CASCADE 2 User manual

SRCC OG
SRCC OG- -300 Certified Solar Water Heating System 300 Certified Solar Water Heating System
Installation, Operation and Maintenance Manual
Installation, Operation and Maintenance Manual

CASCADE 2
DOMESTIC SOLAR WATER
HEATING SYSTEM
INSTALLATION, OPERATION AND MAINTENANCE MANUAL
The Cascade 2 domestic water heating system has gone through an extensive design, technical and per-
formance review by the Solar Rating & Certification Corporation (SRCC). The installation of your Cascade
2 system is intended to be executed by properly licensed and experienced professional contractors in ac-
cordance with SRCC Standard OG-300, “Operating Guidelines and Minimum Standards For Certifying”,
and shall conform to applicable federal, state and local regulations, codes, ordinances and standards gov-
erning the installation of solar water heating systems.
The solar energy system described by this manual, when properly installed and maintained, meets the
minimum standards established by the SRCC. This certification does not imply endorsement or warranty
of this product by the SRCC.
OG-300 system certification is granted to SunEarth by the SRCC. It may not be used for any commercial
purpose without prior written consent of SunEarth. SunEarth must approve any deviation from the mate-
rials and methods described in this manual in writing.
The Cascade 2 Drainback solar water heating systems can be protected against freeze damage
to temperatures as low as -50ºF (-46ºC). This system should not be installed in areas within
the continental United States where the annual ambient temperature has ever fallen below
minus 50° Fahrenheit (-46° Celsius). The Cascade 2 Drainback system must be installed as
specified in this manual to have effective freeze protection at these low temperatures.
Freeze tolerance limits are based upon an assumed set of environmental conditions. Extended periods of
cold weather, including ambient air temperatures above the specified limit may cause freezing in exposed
parts of the system. It is the owner’s responsibility to protect the system in accordance with SunEarth’s
instructions if the ambient temperature approaches the specified freeze tolerance limit.

TABLE OF CONTENTS
1)Introduction ......................................................................... 1
2)System Description and Operation Principle ........................ 1
3)Installation Requirements—General ..................................... 2
4)Installation Requirements—Specific ..................................... 2
5)Start Up Procedures ........................................................... 13
6)Modes of System Operation ................................................ 13
7)System Shut Down and Isolation Procedures ..................... 14
8)Vacation procedures .......................................................... 14
9)Maintenance and Troubleshooting ...................................... 14
10)Cascade 2 System Component Parts ................................. 15
11)Estimated Component Life ................................................ 16
12)System Operating Parameters .......................................... 16
Appendix A. Approved Primary Components........................... 18
Appendix C. System and Component Labels ........................... 22
Appendix F. SunEarth Collector Warranty Statement ............. 24
Appendix G. SRCC OG-300 Certified System Model Numbers . 26
Appendix H. Supplier and Service Contact Information ......... 27

IMPORTANT SAFETY INFORMATION
READ ALL INSTRUCTION BEFORE USING
!DANGER!
WATER TEMPERATURE SETTING
Safety and energy conservation are factors to be considered when selecting a water temperature setting
of the water heater’s thermostat. 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.
Temperature Time To Produce a Serious Burn
120°F More than 5 minutes
125°F 11/2 to 2 minutes
130°F About 30 seconds
135°F About 10 seconds
140°F Less than 5 seconds
145°F Less than 3 seconds
150°F 11/2 seconds
155°F About 1 second
Time/Temperature Relaonship in Scalds
Table courtesy of Shriners Burn Instute
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 thermostat setting to prevent con-
tact with “HOT” water.
NOTICE: Mixing valves should be installed to reduce the
point of use water temperature by mixing hot and col wa-
ter in branch water lines. Contact a licensed installer or
the local plumbing authority for further information.
The temperature of the water in the water heater can be regulat-
ed by setting the temperature dial of the adjustable surface
mounted thermostat located behind the jacket access panel.
!DANGER!: Hoer water increase the potenal for hot
Water SCALDS.
!DANGER! Burns from Hot Water and Steam—Use
extreme care when opening relief valves,
and filling storage tanks.
The electrical element booster thermostat has been factory set
at 50°C (120°F) to reduce the risk of scald injury. Adjusting the
thermostat to a higher setting is not recommended. Hotter wa-
ter increases the potential for Hot Water Scalds.
This thermostat controls the
water heater’s heating ele-
ment only. ( A separate
thermostat should be uti-
lized in monitoring the tem-
perature from the collector).
To comply with safety regu-
lations the thermostat is
factory set at 120°F or less
where local codes require.

IMPORTANT SAFETY INFORMATION
READ ALL INSTRUCTION BEFORE USING
!WARNING!
For your safety, the information in this manual must be followed to minimize
risk of fire or explosion, electric shock, or to prevent property damage, person-
al injury, or loss of life.
Be sure to read and understand the entire installation, Operation and Mainte-
nance manual before attempting to install or operate this water heating sys-
tem. It may save you time and cost. Pay particular attention to the Safety in-
structions. 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 service
technician, or the local utility.
!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 over-
heating, fire, flood, or physical damage or if the ECO fails to shut off.
 Read this manual entirely before in-
stalling or operating the water heating
system.
 Use this appliance only for its intended
purpose as described in this installa-
tion, operations and Maintenance Man-
ual.
 Be Sure your appliance is properly
installed in accordance with local codes
and the provided installation instruc-
tions.
 Do not aempt to repair or replace
any part of your water heang system
unless it is specically recommended
in this manual. All other servicing
should be referred to your installing
contractor or local SunEarth distribu-
tor.
READ AND FOLLOW THIS SAFETY INFORMATION
CAREFULLY.
SAVE THESE INSTRUCTIONS

PREFACE
Let us first offer two words of grateful appreciation.
Thank You!. We sincerely appreciate your business.
SunEarth also wishes to say thank you for “going so-
lar”. Solar water heating systems help to reduce our
nation’s dependence on polluting fossil fuels, minimize
the greenhouse gas emissions associated with conven-
tional water heating and, very importantly, lower you
monthly utility costs.
Established in 1978, SunEarth is a leading U.S. solar
equipment manufacturer. Our products include the in-
dustry standard Empire, Imperial, ThermoRay and Sun-
belt solar water heating collectors as well as the Cop-
perHeart integral collector storage system and SunSi-
phon packaged Thermosiphon systems, SunBurst all
copper absorber plates, Solar Strut and RexRack
mounting hardware. We also fabricate specialty collec-
tors for unique architectural and building applications.
SunEarth SRCC OG-300 certified solar water heating
systems are sold by leading solar plumbing and build-
ing contractors throughout the United States.
Your Cascade 2 solar water heating system has been
designed to meet exacting SRCC OG-300 certification
requirements. The components found in your system
have been selected by your installation contractor for
their proven reliability, longevity and performance in
your specific region of the country.
SunEarth Inc. maintains a policy of continuous review
and improvement to ensure that Cascade 2 systems
incorporate any appropriate technological advances. To
ensure that products represent the current state of the
art in solar water heating Cascade 2 systems are sub-
ject to change without notice. Please consult the
SunEarth website at www.sunearthinc.com for current
information and the latest manual revisions.
1) INTRODUCTION
Solar water heating systems are climate and site spe-
cific appliances. Different types of solar systems are
installed around the world in accordance with regional
weather and water quality conditions. System perfor-
mance varies as a function of the household hot water
load, average ground water, ambient air temperature,
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 Cascade 2 system will save on an an-
nual basis.
Your Cascade 2 Drainback solar system is known as a
“forced circulation closed loop drainback” system be-
cause it utilizes a mechanical pump to efficiently circu-
late water throughout the unpressurized closed loop
solar piping. The “drainback” connotation refers to the
freeze-protection mechanism used in the system. In
drainback systems, the heat exchange fluid (water) in
the collector array and solar loop piping drains back by
gravity into the drainback storage reservoir when the
pump stops circulating. Air replaces water in the col-
lector array and solar loop piping to prevent it from
freezing when the pump is off.
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 Cas-
cade 2 solar water heating system. This system is re-
quired to be installed by properly licensed solar or
plumbing contractors in accordance with SRCC OG-300
and all applicable national, state and local codes, ordi-
nances and regulations governing solar water heating
installations, as well as good trade practices. Failure to
follow the procedures and practices described in this
manual may void the manufacturer’s warranty and spe-
cific component parts.
This manual covers installations utilizing one or two
SunEarth solar collectors with a single solar storage
tank and also two tank systems that include a solar
storage tank and supplemental tank type or tankless
water heater. Frequent reference is made throughout
this manual to specific component parts. The place-
ment of each component can be seen in the system
schematic Figures 3 & 4. A description of each compo-
nent and its function is found in Section 10.
2) SYSTEM DESCRIPTION AND OPERATIONAL
PRINCIPLE
The key components in the Cascade 2 solar water heat-
ing system include the SunEarth solar collector, solar
storage tank, circulation pump and differential temper-
ature controller.
The SunEarth solar collector is the heart of the Cascade
2 system. Simply stated, when the sun is shining, heat
energy is absorbed by the solar collector’s absorber
plate and transferred to the potable water circulating
between the solar collector and storage tank. This pro-
cess is continuously repeated during the average sunny
day as the temperature in the solar storage tank rises.
The differential temperature controller is the brain of
the system. The controller uses temperature sensors to
consistently monitor the temperatures at the collector
and at the tank. the controller automatically turns the
pump on when useful heat is available at the collector
and turns the pump off when there is insufficient solar
heat available or the tank had reached maximum tem-
perature. Cascade 2 systems are designed to provide
two modes of operation. The system will, (1) serve as a
preheater to your solar storage tank, or (2) bypass the
solar collector and run 100% on utility or conventional
fuel. The installation of an optional water heater time
switch allows you to control both the frequency and
duration of supplemental electric resistance water
heating. Supplemental electric heat may not be re-
quired for much of the year depending upon your spe-
cific requirements, thus providing an effective third
mode of operation—100% solar.

Section 6 provides instructions for setting the system
for automatic operation in each of these two modes.
The water in the SunEarth collector and the solar loop
piping automatically drains back into the drainback res-
ervoir each time the circulating pump turns off. Gravi-
ty drains the piping and provides the freeze protection
for your Torrent Drainback system.
To ensure proper drainage the SunEarth solar col-
lector must be installed in the vertical position so
that the internal riser tubes are run parallel, not
perpendicular, to the slope of the roof.
The system also can be manually drained in order to
protect the integrity of the collector and solar loop pip-
ing if it is exposed to extended periods of disuse or
persistent hard freeze conditions below - 50° Fahren-
heit. (See Section 7 for instructions).
3) INSTALLATION REQUIREMENTS—GENERAL
3.1 Permits:
The contractor shall obtain all required permits and ap-
provals.
3.2 Codes, Ordinances and Standards:
The installation shall conform to all federal, state and
local regulations, codes, ordinances and standards gov-
erning the installation of solar water heating systems.
The contractor shall adhere to sound building safety
and trade practices. Special consideration must be giv-
en to building code requirements for roof loading and
the penetration of structural members as well as fire
rated assemblies.
3.3 Shading Considerations:
The collectors must be located in an area of the roof or
otherwise that will not be shaded for the majority of
the day all year round. Adjacent buildings and tress
should be checked for possible shading. The collector
should not be shaded by any permanent obstacle be-
tween 9:00 a.m. and 3:00 p.m. on any day of the year.
A shading instrument such as the Solar Pathfinder can
be used for solar site analysis.
3.4 Roof and Site inspection:
Before the installation, the contractor shall inspect the
condition of the roof and notify the homeowner of any
existing roof damage or necessary repairs.
3.5 Structural Considerations:
The collectors must be located in a structurally sounds
area of the roof. Penetrations into structural members
must not compromise the structural properties of the
member.
ENSURE THAT ALL STRUCTURAL MEMBER PENE-
TRATIONS COMPLY WITH APPLICABLE CODES.
The collector mounting method must be capable of
maintaining the required tilt and azimuth of the collec-
tor under the expected dead loads, winds loads, snow
loads and seismic loads for the location.
3.6 Building Envelope:
Penetrations though the building envelope (including
roof, walls or floor penetrations) must not impair the
enclosure function and must meet applicable codes and
best practices.
Roof penetrations whether for structural mounts or
pipe penetrations must be sealed and leak proofed as
per applicable codes and national Roofing Contractor
Association practices.
Building penetrations must not allow vermin intrusion.
3.7 Fire-Rated assemblies:
Penetrations through fire-rated components must not
reduce the fire resistance of the assembly below code
requirements.
3.8 Building Materials:
Building materials adjacent to solar components must
not be exposed to elevated temperatures.
3.9 Confirmation of Installation Site:
The homeowner and contractor shall confirm the loca-
tion of all roof and other mounted components in ad-
vance of the installation.
3.10 Fluid Identity and Toxicity
The Cascade 2 Drainback system uses water as a heat
transfer fluid, this is heated in the collector and indi-
rectly heats the domestic hot water through the exter-
nal heat exchanger. Use of toxic heat transfer fluids is
prohibited.
3.11 Maintenance and Servicing
When installing the system, make sure that all the
components are accessible and easy to reach. Provide
for clear access to the storage tank, pump, mixing
valve and other key components. If a component in the
potable water side of the system may require future
maintenance or service make connections with brass
unions or other approved methods.
4) INSTALLATION REQUIREMENTS—SPECIFIC
4.1 Collector Orientation
Fig.1
S
COLLECTOR ORIENTATION

Fig.2
SINGLE TANK SYSTEM
SCHEMATIC
1
2
48”
min.
T1
9
17
3
10
11
12
13
14
PIPE
INSULATION
T2
8
20
HOT SUPPLY
LINE TO FIXTURES
COLD SUPPLY
LINE
T3
4
24
25
(1) SunEarth Solar Collector(s)
(2, 3, 4) Temperature Sensor
(5, 6, 7, 8, 22) Ball Valve
(11, 24, 35, 36) Combinaon Valve
(9) Pressure Relief Valve
(10) Drain Back Tank
(12, 13) Pump
(14) Heat Exchanger
(17) Dierenal Temperature Controller
(18) Heang Element & Tank Thermostat
(19, 20) Temperature and Pressure Relief Valve
(21) Mixing Valve
(23) Water Heater
(25) Solar Tank
22
35
ROOF JACKS
36

Fig.3
TWO TANK
SYSTEM
SCHEMATIC
COLD SUPPLY
LINE
HOT
SUPPLY
LINE TO
FIXTURES
7
6
5
8
18
19
1
2
(1) SunEarth Solar Collec-
tor(s)
(2, 3, 4) Temperature
Sensor
(5, 6, 7, 8, 22) Ball Valve
(11, 24, 35, 36) Combina-
on Valve
(9) Pressure Relief Valve
(10) Drain Back Tank
(12, 13) Pump
(14) Heat Exchanger
(17) Dierenal Temper-
ature Controller
(18) Heang Element &
Tank Thermostat
(19, 20) Temperature
and Pressure Relief Valve
(21) Mixing Valve
(23) Water Heater
(25) Solar Tank
20
48”
min.
T1
21
9
17
4
3
10
11
12
13
14
T3
PIPE
INSULATION
T2
22
24
23
25
35
ROOF JACKS
36

TANKLESS
SYSTEM
SCHEMATIC
Fig.4
COLD SUPPLY
LINE
HOT
SUPPLY
LINE TO
FIXTURES
7
6
5
8
1
2
20
48”
min.
T1
21
9
17
4
3
10
11
12
13
14
T3
PIPE
INSULATION
T2
22
24
23
19
25
(1) SunEarth Solar Col-
lector(s)
(2, 3, 4) Temperature
Sensor
(5, 6, 7, 8, 22) Ball Valve
(11, 24, 35, 36) Combina-
on Valve
(9) Pressure Relief Valve
(10) Drain Back Tank
(12, 13) Pump
(14) Heat Exchanger
(17) Dierenal Temper-
ature Controller
(18) Heang Element &
Tank Thermostat
(19, 20) Temperature
and Pressure Relief Valve
(21) Mixing Valve
(23) Water Heater
(25) Solar Tank
35
ROOF JACKS
36

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 collec-
tor should not be shaded by any permanent obstacle
between 9:00 a.m. and 3:00 p.m. on any day of the
year.
4.2 Collector Tilt
Optimal annual efficiency is achieved by tilting the so-
lar collector at and angle that equals your latitude plus
an additional 10°. This tilt angle favors the lower winter
sun when the collector performance is at its lowest and
minimizes overheating during the hottest summer
months.
To ensure proper water drainage from the glazing the
collector must be sloped from horizontal. Never mount
the collector parallel to a flat roof. Use SunEarth
RexRack, Landscape Rack or Universal Tilt Kit products
to raise the collector to a proper angle. The minimum
acceptable tilt angle from horizontal is 15°.
The solar collectors in a two collector staggered mount
installation must be spaced far enough apart to prevent
winter shading when the sun is at its lowest angle on
the winter solstice.
4.3 Basic Mounting Procedures
The SunEarth solar collector in your Cascade 2 Drain-
back solar system must be mounted in a vertical orien-
tation parallel to the slope of the roof. See Figure 1.
This orientation allows the internal riser tubes to rapid-
ly drain when the circulation pump shuts off.
CRITICAL: Both the collectors and the solar loop
piping must be sloped to drain away from the
highest point in the system back to the drainback
reservoir.
The minimum required slope is 1/4” vertical drop per
foot of horizontal piping run (2% minimum slope). Use
the steepest slope possible on the return line piping to
the drainback reservoir. Water will drain down both the
return tubes directly to the drainback reservoir and the
supply tubes by spinning the pump impeller in the re-
verse direction.
The collector should be mounted as close to the stor-
age tank as possible to minimize heat loss in the piping
runs. If the home has attic access, mounting the collec-
tors near the roof peak provides for additional attic
workspace.
The solar collector should be mounted on the roof in
accordance with these general principles:
4.3.1 The most important structural considerations is
to securely anchor the solar collector and the SunEarth
mounting hardware to the structural members of the
roof with stainless steel hanger bolts, lag bolts, stand-
off mounts or other approved roof attachment meth-
ods. The solar collector shall be attached to the mount-
ing hardware as detailed in Figures (6-9). (Note: The
drawings in the manual detail mounting hardware for
the SunEarth Empire, Imperial, SunBelt and Ther-
moRay series collectors.)
4.3.2 The collector should be raised from the roof sur-
face to allow for rainwater and debris to pass under the
collectors and for proper ventilation of the roofing ma-
terial. There should be at least 11/2” of clearance be-
tween the roof surface and the bottom of the solar col-
lectors. Local codes may require greater clearance and
shall be followed accordingly.
4.3.3 When selecting mounting hardware and fasten-
ers it is extremely important to avoid galvanic corro-
sion resulting from the direct contact of incompatible
STRUT ON FOOT MOUNT FOR
COMPOSITION ROOF
Fig.6
COLLECTOR
C-SSN
FOOT MOUNT
FLASHING
STAINLESS LAG BOLT
REXRACK
Fig.5
FRONT
MOUNTING FOOT
REAR
TELESCOPING LEG
SUPPORT STRUT
C-SSN

metals. Use of SunEarth anodized aluminum Solar
Strut mounting hardware and stainless steel lag or
hanger bolts, fastening hardware is recommended. In
climates subject to severe winters or high humidity use
of galvanized fasteners is prohibited.
4.3.4 Preserving the integrity of the roof membrane is
the most important roofing consideration. Ensure that
all roof penetrations required to plumb
and mount the solar collectors are properly flashed and
sealed in accordance with standard roofing practices
and in compliance with all local codes and ordinances.
4.3.5 If the region is subject to hurricane conditions,
additional steps may be required to secure the collector
and mounting hardware to the structural members. In
certain areas of the country, local building codes may
require collector wind load testing or prescribe specific
mounting procedures. Consult you local building de-
partment regarding any special considerations for your
area.
4.4 Collector Loop Plumbing
The collector loop must be plumbed using copper or
stainless steel piping and copper, brass, bronze or
stainless steel fittings. Lead-free solder shall be used.
Use of galvanized steel, CPVC or PVC is prohibited.
PEX may be used only in systems that meet the follow-
ing conditions:
 The PEX tubing shall not be exposed to sunlight.
 Water must be used as the heat transfer fluid.
 The system shall be non-pressurized (capped at at-
mospheric on the day of installation) or shall be
vented to atmosphere.
 A length of uninsulated copper tube no less than ¾”
nominal diameter shall be used at the hot outlet
and cold inlet of the solar collector(s) for a distance
of no less than three feet (3’) before the transition
is made to PEX tubing.
 All connections in the PEX piping runs shall be ap-
proved by the PEX manufacturer for potable water
piping.
 The system shall have a pressure-only relief valve
installed at the drainback tank location or shall be
vented to the atmosphere. The pressure rating for
the relief valve shall be no less than 25 psi and no
more than 50 psi.
The collector loop pipe sizing must be adequately sized
to handle the design flow rates for the collector(s).
SunEarth recommends ¾” nominal diameter pipe sizes
for two collector systems and ½” nominal diameter
pipe sizes for one collector systems, except for the re-
turn piping from the collector to the drainback tank,
this should always be ¾” or larger.
STRUT ON STANDOFF FOR
CURVED TILE ROOF
Fig.9
STAINLESS LAG BOLT
LEAD FLASHING
STANDOFF
C-SSN
COLLECTOR
BASEFLASHING
STRUT ON STANDOFF FOR
COMPOSITION ROOF
Fig.8
STAINLESS LAG BOLT
LEAD FLASHING
STANDOFF
C-SSN
COLLECTOR
STRUT ON STANDOFF FOR FLAT
TILE ROOF
Fig.7
STAINLESS LAG BOLT
LEAD FLASHING
STANDOFF
C-SSN
COLLECTOR

CAUTION: The solar loop piping from the collector(s) to
the drainback tank must be no less than 3/4” T-M cop-
per tube to allow air to migrate up the tube ensuring
full draining of the collector(s) and tubes.
It may be necessary to increase the pipe size for longer
pipe runs or reduce the pipe size for shorter runs or
higher efficiency pumps. The pipe must be large
enough that the velocity of the water in the pipe does
not exceed 4 ft/s. Hot water flowing at over 4 ft/s in a
pipe will erode the pipe and reduce system life.
When more than one collector is used in the system,
the collectors should be plumbed in a reverse return
piping arrangement in order to maintain equal flows
through all collectors in the array during normal opera-
tion.
To ensure proper drainage of the collector array and
solar loop piping the lines must be adequately sloped
to drain back to the drainback reservoir.
CRITICAL: The required slope is 1/4” vertical drop per
foot of horizontal run (2% slope). Failure to properly
orient the collector and solar loop piping to allow ade-
quate drainage may result in freeze damage. SunEarth
solar collectors are not warranted against freeze dam-
age.
Figure 11 illustrates correct and incorrect methods of
plumbing the solar collector array. Note that water will
trap in the “U” section of piping as illustrated in the
drawing marked incorrect thus making it susceptible to
freeze damage.
Piping in new solar installations can be covered with
dirt, grease, solder flux or other impurities that may
affect the system performance. A thorough cleaning is
required before charging. A Water soluble flux should
be used when soldering pipe joints in the collector loop
in order to facilitate system flushing. Carefully review
the cleaning procedures in “Charging the System” out-
lined below.
All vertical piping between the storage tank and the
collector shall be supported at each story or at maxi-
mum intervals of ten feet (10’). Horizontal runs shall
be sloped to drain (minimum 2% slope) and supported
every five feet (5’) to prevent sagging. Roof runs shall
be secured and supported providing at least 1-1/2
inches clearance from roof. Pipe supports shall be con-
structed from a material that will not rot, compress or
degrade over time as this may lead to pipe sagging and
failure to drain. Standard best piping practices shall be
followed as described in the Uniform Plumbing Code,
International Plumbing Code or other recognized code
or standard. Copper plumbers tape or tube strap is
required. The pipe insulation should not be com-
pressed or crimped by the strapping material.
Allowance should be made for expansion and contrac-
tion of piping due to changes in temperature of the wa-
ter and piping. Use flexible pipe supports and avoid
long straight piping runs. Include bends and elbows to
allow for expansion such as swing joints at the collector
inlet & outlet.
The installation of all horizontal and vertical piping may
not reduce the performance or rating of any structural
member or fire rated assembly. Adhere to all applicable
local codes and ordinances.
4.5 Pipe Insulation
WARNING: HOT PIPES MAY CAUSE BURNS IF
TOUCHED. ENSURE THAT ALL PIPES AND FIT-
TINGS ACCESSIBLE TO THE PUBLIC ARE WELL IN-
SULATED. COMPONENTS ACCESSIBLE TO PUBLIC
TRAFFIC MUST BE KEPT BELOW 140°F OR CLEAR-
LY LABELLED WITH AN APPROPRIATE WARNING.
The collector loop piping, plus any interconnecting hot
water piping shall be well insulated with high quality
flexible closed cell insulation to minimize heat loss. The
COLLECTOR PLUMBING—SLOPED
TO DRAIN
Fig.10
1” CC CAP
1” x 3/4” CC 90°ELBOW OR COUPLING
1” CC CAP 1” x 3/4” CC 90°ELBOW OR COUPLING
SUPPLY LINE
1” CC COUPLING
1” CC COUPLING
RETURN LINE
CORRECT INCORRECT
COLLECTOR PLUMBING
WILL TRAP FLUID
Fig.11

insulation shall have a maximum operating tempera-
ture of 220°F or higher. The wall thickness of the pipe
insulation should be not less than 1/2”. A 1” wall thick-
ness is required for exposed piping in all areas prone to
annual hard freeze conditions. When it comes to pipe
insulation the rule is simple: thicker is better.
To the extent possible, slide the insulation material
over the pipe without cutting or taping. All butt joints
must be sealed with contact adhesive. The use of rigid
polyethylene pipe insulation is prohibited. The temper-
atures generated by your collector in the summer
months or under stagnation conditions can melt this
type of material.
Any above ground exterior pipe insulation is subject to
UV degradation and must be jacketed, wrapped with
aluminum foil tape, or painted with two coats of high
quality water-based acrylic resin coating as supplied by
the insulation manufacturer.
4.6 Control System
4.6.1 Differential Controller
The differential controller must be installed in an acces-
sible location so that the user interface, typically an
LCD screen, can be seen. Switches on the controller
must be labeled and accessible. Always follow the con-
troller manufacturers wiring instructions when installing
differential controllers. Control system inputs; such as
signals from the temperature sensors or flow meters
shall be connected to the appropriate low voltage ter-
minals. Controller output to the pumps will be medium
voltage, 110 VAC or 220 VAC. Medium voltage power
to the pump may be supplied by a line cord from the
pump to an outlet in the controller or hard wired from
the controller medium voltage terminals to the pump.
Wiring must comply with standard electrical practice
and all applicable electrical codes for the jurisdiction
having authority, this may require the use of conduit
for medium voltage wiring.
The differential controller must have a provision to
manually turn the pump on and off (manual override)
so that the pump operation can be checked at any time
and the pump can be manually stopped if required for
maintenance or troubleshooting purposes.
Set the maximum tank temperature to the desired
maximum temperature, this temperature must be low-
er than the rated maximum temperature of the tank an
associated components. When the solar loop heats the
tank to the temperature, the pump will shut off
preventing further heat gains to the solar tank.
4.6.2 Collector Sensor Placement
The collector sensor shall be located on the solar loop
return line as close to the collector as possible. Sensors
are typically accurate to ±1/2°F if properly installed and
weatherized. The collector probe sensor shall be at-
tached to the SunEarth collector header pipe either
with a stainless steel hose clamp or by inserting the
probe sensor into a thermal well in contact with the
fluid near the outlet header pipe.
It is recommended that the connection between the
silicon sensor lead and low voltage sensor wiring be
made inside the attic, a NEMA 4X junction box or some
other indoor space. When using wire nuts to make the
connection, the crimped brass cap on the end of the
sensor should be removed and the wire stripped before
inserting into the wire nut for connection. Where con-
nections from the sensor lead to the low voltage wiring
is made at an exposed location the connection should
be crimped and insulated with heat shrink or soldered
and insulated with heat shrink. Wire nuts or screw con-
nectors should not be used in exposed locations due to
the likelihood of corrosion which will result in a com-
promised electrical connection. Thoroughly wrap and
weatherize the insulation with electrician’s tape or insu-
lation tape as provided by the manufacturer. See Fig-
ure 12 for collector sensor installation detail.
If an electrical potential exists between the roof and
ground, this may induce current in the collector sensor
wire. This current will result in a false signal being re-
ceived by the controller and hence incorrect tempera-
ture measurements. To prevent this current the collec-
tors absorber plate and piping should be independently
earth grounded. This will provide a separate path to
ground from the roof which does not interfere with the
sensor readings.
Grounding can be achieved by running a separate
ground wire to the collectors or ensuring that the pipe
in the solar loop is grounded and that there are no
electrical discontinuities between the grounding point
and the collectors absorber. Grounding of the collector
& roof piping is especially important in locations that
often experience electrical storms and electrical atmos-
pheric activity.
4.6.3 Low Voltage Wiring
The low voltage wiring used in to connect the sensor
lead to the controller shall be a minimum 18 AWG. The
COLLECTOR SENSOR
Fig.12
SILICON SENSOR LEAD MAY
BE IN CONTACT WITH PIPE
SENSOR CLAMPED TO HEADER PIPE
& COVERED WITH INSULATION
CRIMP OR SOLDER
CONNECTION
SENSOR WIRE MUST
NOT BE PLACE IN
DIRECT CONTACT
WITH PIPE
PROTECTIVE INSULATION
JACKET OR APPROVED
COATING
RETURN LINE

wiring should be bare or tinned copper, two conductor,
stranded, PVC insulated, with a PVC UV rated jacket
suitable for exterior use. In locations that often experi-
ence electrical storms and electrical atmospheric activi-
ty the low voltage sensor wire should also be shielded
with the shielding grounded.
Low voltage wire shall be rated for the full ranges of
temperatures expected in the location, typically wire is
rated up to 160°F. The low voltage sensor wire must
not be in direct contact with the pipes as the wire insu-
lation may melt when in contact with a hot pipe. Low
voltage sensor wire must be run OUTSIDE the pipe in-
sulation. Where the low voltage wire is run in an ex-
posed location, it should be run OUTSIDE the pipe insu-
lation but UNDER the insulation jacket or wrap to pro-
tect the wire from UV exposure.
4.7 Installing the Solar tank
The solar tank is heated indirectly through the external
heat exchanger by separate pumps on the collector
loop and the potable side of the heat exchanger.
When plumbing the SunEarth solar storage tank and
drainback reservoir make sure that all the components
are accessible and easy to reach. Ensure that there is
clear access to the storage tank, circulating pump,
drainback reservoir, mixing valve, flow meter and other
key components. If a component in the potable water
side of the system may require future service or
maintenance make the connections with brass unions.
Use only brass nipples and unions and copper and
brass fittings in plumbing the solar storage tank and
drainback reservoir. The use of galvanized fittings or
nipples, CPVC or PVC piping is prohibited.
Check valves are NOT ALLOWED anywhere in the col-
lector loop. A check valve in the collector loop will pre-
vent proper draining of the collectors and may result in
freeze damage. If the pump used has an integral
check valve, the check valve must be removed before
installing the pump in the system.
Hard copper connections to the city cold water supply
line and the home hot water feed lines are recom-
mended. The gaskets in standard water heater flex
hose connectors can become brittle and compressed
over time and begin leaking on the water heater. If
not detected in a timely manner even a small drip or
leak may cause serious damage to the tank’s electrical
components or, in extreme cases, may cause the tank
to leak from the outside in.
Tank plumbing is required to provide for the isolation of
the solar storage tank from the city cold water supply
line by means of an isolating ball valve.
The differential temperature controller shall have a
screen readout to show temperatures of the collector
and storage tank. Otherwise, line thermometers shall
be installed in the collector supply and return lines to
allow for a simple diagnostic check of proper system
operation. On a sunny day the hot water return line
should be approximately 5 –15°F warmer than the wa-
ter in the collector supply line.
The specified SunEarth controller continuously displays
the temperature of the SunEarth collectors (T1) and
the temperature at the bottom of the solar tank (T2).
In addition, you may choose to install a third tempera-
ture sensor (T3); this is normally installed at the hot
water outlet on both single and double tank systems.
The Torrent Drainback system typically requires a high
head, low flow circulating pump. The maximum head
on the pump curve must be greater than the static lift
head required to fill the system. The static lift head is
the vertical height from the bottom of the drainback
tank to the highest point in the system (usually the col-
lector outlet header). When the pump is filling the sys-
tem it will be pumping against the static lift head and
should provide no less than 0.5 GPM flow. Once the
system has been filled to the top of the collector, water
will start to cascade down the return line filling the re-
turn line as far as the drainback reservoir. Once this
pipe is fully flooded the return line will start to siphon,
resulting in an increase in flow as the system transi-
tions from the filling condition to the running condition.
In the running condition the flow rate should not ex-
ceed 5 GPM. Good pump selection requires that the
pump provide enough lift for the filling condition with-
out excessive flow in the running condition. This is
usually achieved using a pump with a “steep” pump
curve. For multistory buildings, this can be especially
challenging unless the drainback tank is located on the
upper floor.
When there is a risk of pump cavitation due to high
flow rates, a pump throttling valve (COMPONENT #22)
may be located on the discharge, or upstream, side of
the pump to adjust the solar loop flow rate and to pre-
vent cavitation of the circulating pump. Cavitation is a
fluid condition that can lead to pitting or other damage
to the pump impeller. A throttling valve on the return
piping from the collector to the drainback tank can also
TANK SENSOR
Fig.13
THERMOWELL JIFFY CLIP (ALTERNATIVE)

be beneficial in situations where excessive noise is ex-
perienced due to high flow rates into the drainback
tank.
A brass boiler drain (COMPONENT #11) must be in-
stalled at the lowest point in the system to allow for
charging the solar loop piping and to serve as a drain
valve for manual draining and maintenance.
A high quality thermostatic mixing valve is a required
component in all OG-300 certified systems and should
be plumbed in line with brass union connections for
ease of future repair or replacement. The mixing valve
shall be standard ASSE 1017 approved. The specified
mixing valve should have an operating range between
95°F and 120°F. The mixing valve shall include a set
point of 120°F delivered water temperature.
WARNING: SCALDING CAN OCCUR WITHIN FIVE SEC-
ONDS WHEN WATER TEMPERATURES APPROACH 140°
F. DESPITE THE INSTALLATION OF A MIXING VALVE
IN YOUR TORRENT DRAINBACK SYSTEM, ALWAYS EX-
ERCISE CAUTION WHEN OPENING A HOT WATER FIX-
TURE OR FAUCET IN YOUR HOME.
The 3/4” cold water supply line to the solar storage
tank shall be insulated with R-2.6 or greater pipe insu-
lation to a minimum distance of 5’ behind the storage
tank, or to the wall if closer than 5’.
Figures 11, 12 and 13 show the plumbing schematics
for single and two tank Torrent Drainback systems. A
brief explanation of the main components and their
function is found in Section 10 below.
4.8 Tank Sensor Placement
Figure 13 details the proper placement of the solar
storage tank sensor. The tank sensor shall have good
thermal contact with the tank wall in order to accurate-
ly measure the temperature of the water at the bottom
of the tank. It is recommended that the sensor be in-
stalled in a brass or copper thermal well screwed into
the lower sensor port in the tank.
Thoroughly weatherize the wire connections in accord-
ance with section 4.6.2.
4.9 Tank Insulation
Conventional back-up electric water heaters have insu-
lation values between R-12 and R-20. the R value ex-
presses the thermal resistance of the tank insulation.
The higher the “R-value” the more effective the insula-
tion is at preventing heat loss. The use of any solar
storage tank with an R value belowR-12 is prohibited.
The storage tank should not be placed directly on an
un-insulated floor or concrete slab, in order to prevent
moisture damage to the base of the tank and reduce
the heat loss to the floor. The tank should be raised off
the floor on a pad.
4.10 Choosing and Installing the Drainback Res-
ervoir
SunEarth CopperStorTM copper drainback tanks are
available in 2.5; 5; 7.5 and 10 gallon capacities. Stain-
less steel drainback tanks are available in 10; 15 and
20 gallons. Small glass lined steel electric water heat-
ers available in various sizes from 6 to 20 gallons can
also be used as drainback tanks; do not connect the
heating element when using these tanks as a drainback
reservoir. The minimum drainback tank volume must
be DOUBLE the volume of the piping and collector loop
above the initial fill level of the system. This volume is
calculated from the fluid capacity of all the collectors in
the system plus all piping above the drainback tank fill
level.
Select the appropriate tank based on the collector(s)
chosen and the total length of solar supply and return
loop piping in the system. Table 1 and Table 2 indi-
cate the proper drainback tank for the two most com-
mon piping scenarios. Our preference is to use Table 1:
1/2” piping for the supply line and 3/4” piping for the
return line. This provides some flow related benefits,
extends the allowable pipe run and is slightly less ex-
pensive.
The drainback reservoir shall be mounted in a location
that is NEVER subjected to freezing conditions. The
drainback tank may be mounted to a wall using brack-
ets or on a stand over the solar tank. The outlet of the
drainback tank should be at least 48” above the suction
side of the circulating pump to give sufficient net posi-
tive suction head available to the pump (See Figures
11, 12 and 13).
The drainback reservoir should be installed at the high-
est location practicable. The benefits of this include:
reduced risk of pump cavitation; reduced pumping
head required to fill the system allowing smaller pumps
to be used; and reduced piping above the drainback
reservoir allowing smaller drainback tanks. In build-
ings with two or more floors, it is beneficial to install
TABLE 1
ARRAY DB-5 DB-7.5 DB-10
1 EP/EC-40 82 138 194
2 EP/EC-21 76 132 188
2 EP/EC-24 73 129 185
2-EP/EC-32 62 118 174
PIPE RUN LENGTHS FOR 1/2” TYPE M AND 3/4” TYPE M
RETURN LINES.
TABLE 2
ARRAY DB-5 DB-7.5 DB-10
1 EP/EC-40 61 103 144
2 EP/EC-21 57 98 140
2 EP/EC-24 54 96 138
2-EP/EC-32 46 88 130
PIPE RUN LENGTHS FOR 3/4” TYPE M AND 3/4” TYPE M
RETURN LINES.

the drainback on the uppermost floor, preferably near
the ceiling.
Drainback tanks are factory insulated to provide both
heat retention and a noise buffer against the sound of
falling water.
If your Torrent Drainback system includes the optional
flow meter it should be plumbed so that the top of the
flow meter is level with the top of the drainback tank
so that the flow meter also provides a visual check of
the fluid level in the system. The top and bottom of
the flow meter should be supported to relieve stresses
on the connecting unions.
DO NOT install the pressure relief valve (COMPONENT
#9) on the drainback tank at this time. The COMPO-
NENT #9 is threaded in place after the solar loop piping
has been filled with water. See Section 4.13 for in-
structions on charging the system.
4.12 Electrical and Wiring Requirements
When the electric element is used as the auxiliary heat
source a properly licensed contractor shall make the
230 VAC electrical connection to the water heater or
storage tank. If your solar contractor is not allowed by
law to make these connections consult a licensed elec-
trician.
Never activate the circuit breaker controlling the elec-
trical heating element until the solar storage tank is
completely filled with water. This will prevent “dry fir-
ing” and destruction of the heating element.
SunEarth recommends the use of a 115 VAC differen-
tial control with a factory installed six foot line cord.
The installation requires one 115 VAC outlet to be lo-
cated neat the solar storage tank. The circulation pump
line cord is then plugged into the receptacle on the
controller. A 230 VAC control and circulation pump may
be substituted where appropriate.
4.13 Heat Transfer Fluid (HTF)
The HTF must be a non-toxic fluid that meets FDA Gen-
erally Recognized as safe (GRAS) Classification. The
Torrent Drainback System uses water to meet this re-
quirement.
Water used to fill the collector loop must meet certain
minimum standards for purity. Impurities in the dilu-
tion water can increase metal corrosion, and cause the
formation of scale and other deposits on the heat ex-
changer’s internal heat transfer surfaces. Distilled or
deionized water is recommended.
4.14 Flushing and Filling the System
Once the components have been plumbed it is time to
fill the solar storage and collector loop with water as
follows:
4.14.1 STEP 1 –Flush and Fill the potable loop with
water.
Close potable flushing combination valves
(COMPONENTS #24 & 36). Fill the solar tank with wa-
ter and check that there are no leaks on the potable
side of the system.
Do this by opening the cold water isolation ball valve to
the solar tank (COMPONENT #8) and opening a hot
water outlet, such as a faucet, until the water runs
freely. When the tank is filled, inspect all threaded fit-
tings and solder joints for leaks.
Connect a washing machine hose to the drain ports of
the potable flushing combination valves (COMPONENT
#24 & 36). Open domestic flushing combination valves
drain ports (COMPONENT #24 & 36).
Open potable flushing valve (COMPONENT #36) and
close valves drain port when water flows out of the
hose. Close domestic flushing valve (COMPONENT #24)
drain valve when water flows clear from the hose.
Open potable flushing valve (COMPONENT #24). Check
for leaks. The entire potable piping is now pressurized
with potable water.
4.14.2 STEP 2 - Flush and Fill the solar loop piping with
water.
Close solar flushing combination valves (COMPONENTS
#11 & 35).
Connect a washing machine hose to the solar flushing
combination valve drain port (COMPONENT #11), open
the solar flushing valve drain port (COMPONENT #11).
Connect the other end of the hose to a water pressur-
ized water source or a utility pressure pump.
Connect a washing machine hose to the solar flushing
combination valve drain port (COMPONENT #35), open
the solar flushing combination valve drain port
(COMPONENT #35). Open the water pressurized water
source. Run until clear water runs from the washing
machine hose connected to the solar flushing combina-
tion valve drain port (COMPONENT #35).
Open the solar flushing combination valves
(COMPONENTS #11 & 35). Close the solar flushing
combination valves drain ports (COMPONENTS #11 &
35), turn off the water source. Verify water level in
drainback tank is within 1 inch from the top of the sight
glass or flow mater; fill or drain as necessary.
4.14.3 STEP 3 –Run the pump to check operation and
TABLE 3—Specifications for SunEarth CopperStor
Drainback Reservoirs
SUNEARTH
MODEL
NUMBER
WIDTH
(IN)
LENGTH
(IN)
DEPTH
(IN)
DRY
WEIGHT
(LBS)
FLUID
CAPACITY
(GAL)
DB-5 12 50 5 42 5.0
DB-7.5 18 50 5 56 7.5
DB-10 24 50 5 84 10.0
MAXIMUM PRESSURE 160 PSIG, CONNECTIONS 3/4”

flush impurities from the collector loop.
At this point it is recommended to run water through
the system to remove any solder flux residue or other
impurities that were introduced into the system during
plumbing. Water soluble flux should have been used
when soldering pipe joints in the collector loop to facili-
tate system flushing. Set the switch on the side of the
SunEarth control to the “ON” position see (fig 16). Al-
low the pump to circulate water through the system for
15-20 minutes. While the pump is running check the
entire collector loop for leaks and ensure that there is
adequate flow.
4.14.4 STEP 4 –Check that Collectors are Draining
Back.
Turn the controller back to the ‘OFF’ position see (fig
16). Allow time for the collectors and piping to drain
into the drainback reservoir. Observe the water level
in the drainback reservoir by means of the site glass,
visual flow meter or by checking with a dowel rod. The
water level in the drainback reservoir should return to
the original fill level after a few minutes. If the water
level does not return to the original fill level, the sys-
tem is not draining properly and may freeze. If water
level does not return to original level, check that the
collectors are tilted with riser tubes at 15°or more and
that all piping is sloped to drain at 2% or more.
4.14.5 STEP 5 - Drain the system to remove impurities.
Drain the cycled water out of the array by placing the
hose attached to the solar flushing combination valve
drain port (COMPONENT #11) into a service drain or
bucket. Open the solar flushing combination valve
drain port (COMPONENT #11) and completely drain the
water from the system.
CAUTION: THIS WATER MAY BE EXTREMELY HOT!
4.14.6 STEP 6 - Refill the system with water.
Connect a washing ma-
chine hose to the solar
flushing combination valve
drain port (COMPONENT
#11) and to a utility pump.
Open solar flushing combi-
n a t i o n v a l v e s
(COMPONENT #11 & 35)
and then slowly pump de-
ionized water into the sys-
tem until the water level is
within 1 inch from the top
of the sight glass or flow meter. Run the system pump
and verify proper operation and that the water level
returns to “set point” on the sight glass or flow meter
when the system drains (circulating pump off).
5) SYSTEM START-UP PROCEDURES
Throughout the installation procedures outlined in Sec-
tion 4, emphasis has been placed on the proper plumb-
ing and wiring of the primary system components. The
solder and threaded connections also have been visual-
ly inspected for leaks and the solar loop piping has
been cleaned and charged. Having successfully com-
pleted these tasks it is time to set your system to run
automatically.
Set the SunEarth control to the ‘ON’ position. Listen
until you can hear water flowing through the solar loop
return piping from the collector.
Place your ear next to the pump and listen for signs of
cavitation. Cavitation sounds like sand running through
the pump and is caused by the implosion of small air
bubbles hitting the pump impeller. Cavitation can dra-
matically reduce the life of the pump and the flow set-
ting valve (COMPONENT #22) should be used to elimi-
nate this condition. If you hear cavitation when the
valve is wide open, slowly close the valve until the
sound is gone.
5.1 Start Automatic System Operation
Set the SunEarth control to the ‘AUTO’ position see (fig
16). Your system is now set to run automatically
whenever solar energy is available to be collected.
6) TWO MODES OF SYSTEM OPERATION
Both single and double tank Torrent Drainback systems
are designed to accommodate two separate modes of
operation. Your system can either (1) serve as a pre-
heater to your conventional electric or gas water heater
or (2) be bypassed entirely and run 100% on utility
power during inclement weather or when maintenance
is required.
Single Tank Operating Instructions:
6.1 Solar Preheat:
Leave the circuit breaker on to your solar storage tank
and set the tank thermostat to the lowest acceptable
temperature setting. The electric resistance heating
element will come on only when the tank temperature
falls below the thermostatic set point. If the solar
heated water entering the tank is warmer than the
thermostatic set point, the electric heating element will
not come on. If you have a water heater timer, you
may preset the timer to turn the heating element on
and off at specified times throughout the day if desired.
6.2 100% Utility Power:
Leave the circuit breaker to your solar storage tank on.
In this mode of operation you must turn off the circula-
tion pump. To turn the pump off, change the opera-
tional setting from automatic to “off”. Failure to turn
off the pump can quickly damage the pump motor,
shaft, bearings or impeller.
Two Tank System Instructions:
6.3 Solar Preheat:
Follow the instructions for the single tank system for
setting the thermostat, heating element or gas fired
water heater or tankless gas water heater for automat-
ic operation. Solar preheat mode operates with the
collectors heating the solar storage tank and supplying
TABLE 4—Design Flow Rates
ARRAY Flow Rate
(GPM)
1 EP/EC-40 1.2
2 EP/EC-21 1.2
2 EP/EC-24 1.6
2-EP/EC-32 1.9

this heated water into the auxiliary tank whenever
there is hot water draw. The ball valves going to and
from the solar storage tank (VALVE # 6 & 7) must be
open while the bypass ball valve (VALVE # 5) must be
closed. See Figure xxx, Solar Preheat.
6.4 100% Utility Power:
Set the thermostat for the auxiliary electric water heat-
er, gas fired water heater or tankless gas water heater
to the desired hot water temperature. 100% Utility
power mode operates by supplying mains water direct-
ly to the auxiliary heater whenever there is hot water
draw, bypassing the solar storage tank. Follow the in-
structions for the single tank system for setting the
thermostat, gas or electric heater for automatic opera-
tion. The ball valves going to and from the solar stor-
age tank (VALVES # 6 & 7) must be closed while the
bypass ball valve (VALVE # 5) must be open. See Fig-
ures xxx, 100% Utility Power.
7) SYSTEM SHUT DOWN AND ISOLATION PROCE-
DURES
Your Cascade 2 Drainback solar water heating system
is designed so that the key components can be easily
isolated for emergency repairs or routine maintenance.
By shutting a single valve you can isolate the entire
system from the pressurized cold water supply line
(COMPONENT #8). In the case of a storage tank or
fitting leak immediately shut this valve and call your
installation contractor for service.
The collector loop can be quickly drained if a leak is
detected or for routine maintenance. Set the SunEarth
control to the ‘OFF’ position. Next, attach a hose to the
lower boiler drain (COMPONENT #11) and open the
valve to drain the system.
CAUTION: THIS WATER MAY BE EXTREMELY HOT!
In two tank systems the solar storage tank can be iso-
lated from the back-up water heater. Set the valve
handles to the 100% utility power configuration as out-
lined above. By closing these valves the tank can be
serviced or replaced. The operation of the back-up wa-
ter heater will not be affected.
8) VACATION RECOMMENDATIONS AND PROCE-
DURES
Solar water heating systems can build up very high
temperatures during summer months if there is no dai-
ly draw on the system. If a short summer vacation is
planned the best way to avoid overheating in a drain-
back system is to set the SunEarth control to the ‘OFF’
position. The pump will not circulate during the day and
the system will not “gain” any additional heat.
For extended vacations of a month or more SunEarth
recommends that you cover the panels with a suitable
opaque material. Stagnation conditions can have an
adverse effect on the internal collector piping if the
panel is left unprotected. SunEarth’s collector warranty
specifically excludes stagnation conditions in excess of
sixty days.
Remember to reset the SunEarth control to the ‘AUTO’
position upon your return and check the system for
proper operation and draining by monitoring the water
levels with the pump on and off.
9) MAINTENANCE AND TROUBLESHOOTING
The following simple procedures are intended to opti-
mize the performance of your Torrent Drainback solar
water heating system and also to extend the life of the
primary components.
9.1 Checking the Water Level
It is important that the drainback reservoir remains full
for proper system operation. To check the fluid level,
set the SunEarth control to the ‘OFF’ position and allow
the fluid in the array to drain into the drainback reser-
voir. For systems installed with an optional flow meter
or sight glass, check to see that the fluid is not less
than 1” from the top of the meter. If your system does
not have a flow meter, unscrew the pressure relief
valve (COMPONENT #9) and dip a wooden dowel into
the threaded copper fitting to check that the fluid level
is not more than 6-8” below the valve fitting. If a
small amount of fluid is needed to bring the reservoir
up to the proper level, pour it directly into the COMPO-
NENT #9 fitting port. Rewrap the thread with Teflon
tape and reinstall the COMPONENT #9. You may also
follow the instructions in section 4.13 for charging the
system if more water is required.
Please remember that over time you WILL lose some
fluid in the solar loop piping. If the water level is
not properly maintained you may do irreparable
damage to your circulating pump. Check your fluid
levels at least once a year.
9.2 Replacing the Anode Rod
The second most important component in your system,
at least from a longevity standpoint, is often ignored
and never seen. We are referring to the sacrificial
“anode rod” installed in your solar storage tank (ST1).
Typically constructed from magnesium, anode rods are
installed in “glass lined” water heaters and storage
tanks to inhibit corrosion.
As the name implies, the “sacrificial” anode rod is con-
sumed so that the tank lining is not. At a certain point
in the process, the anode rod is no longer completely
effective and the corrosive processes begin to eat away
at the tank’s glass lining. In time the solar storage
tank, like any other gas or electric water heater, will
begin to leak. The process is not reversible and the
tank must be replaced.
System temperatures and water quality affect the rate
at which the anode rod is consumed. In general: the
higher the average system temperature the faster the
rate of corrosion. By changing the anode rod after the
fifth year of system operation, and every three to five
years thereafter, it is possible to extend the life of the
solar storage tank. Periodic replacement of the anode
rod in your solar storage tank can significantly extend
the tank life.

9.3 Flushing the Storage Tank
The solar storage tank also should be flushed annually
to minimize sediment buildup on the bottom of the
tank. If you live in an area with high mineral content in
your water, flush the tank on a semi-annual basis. Dis-
connect the power to the solar tank at the circuit
breaker or time switch (if present) before flushing. Set
the SunEarth control to the ‘OFF’ position. In a two
tank system it is not necessary to disconnect the power
to the electric water heater in order to flush the solar
tank.
Open the flush valve on the bottom of the storage tank
and drain a sufficient volume of water to eliminate the
sediment. After the procedure is complete make sure
the tank is completely full of water before restoring
power to the thermostat and heating element. Set the
SunEarth control to the ‘AUTO’ position.
9.4 Cleaning the Collector Glass
If you live in a dusty climate it is beneficial to wash off
the dirt that settles on the collector glass once a
month. Clean glass allows the collector to maintain a
high level of thermal performance.
9.5 Maintaining Pipe Insulation
Check the exterior pipe insulation annually and patch
or repair any exposed surfaces or degraded areas. Re-
pair as necessary with manufacturer’s recommended
jacket or coating or a high quality exterior latex paint.
9.6 Glass Replacement
In the unusual instance of collector glass breakage, the
glass should be replaced immediately. This will reduce
the likelihood of water accumulating inside the collector
and deteriorating the insulation. Contact your installa-
tion contractor to change the glass.
9.7 Leaks
If you detect a water leak in the solar loop piping or
tank plumbing, contact your installation contractor to
service and refill the system.
9.8 Pump Not Circulating
If it’s been a sunny day and you don’t have hot water,
first make sure that the controller is set in the auto-
matic position. If the controller is properly set and the
pump has not been running, unplug the line cord from
the controller receptacle and plug the pump directly
into a nearby 115 volt outlet. If the pump does not run
it may need to be replaced. If the pump does run
when plugged directly into the wall outlet, the problem
may be located in the controller or one of the tempera-
ture sensors. Contact your installation contractor for
service.
9.9 Night Time Heat Loss
If you have a full tank of hot water before bed and the
solar storage tank is cold in the morning make sure
that the circulating pump is not running at night. If the
pump is running and the controller displays questiona-
ble temperatures at the collector or tank (i.e. 180ºF
tank and 45ºF collector), check both sensors using a
resistance meter to see if they are correctly calibrated.
If you find a defective sensor replace it immediately.
9.10 Auxiliary Electric Element not Operating
If the weather is poor and the auxiliary heating ele-
ment will not fire, the bright red reset button on the
thermostat may have to be depressed to be reset. Sin-
gle tank systems have one heating element and ther-
mostat. Double tank systems with conventional elec-
tric water heaters have two heating elements and ther-
mostats.
DANGER: NEVER REMOVE THE PROTECTIVE AC-
CESS PLATE ON THE EXTERIOR OF THE SOLAR
STORAGE TANK OR CONVENTIONAL WATER
HEATER WITHOUT DISCONNECTING THE 230
VOLT POWER SUPPLY AT THE CIRCUIT BREAKER.
After the circuit breaker has been turned off, remove
the access plate on the storage tank or water heater
and depress the red reset button on the thermostat. If
it clicks when depressed the heating element should
fire immediately when you reconnect the circuit break-
er. It the reset button does not click and you do not
have hot water after one hour, the heating element or
thermostat may be defective. Contact your installation
contractor for service.
In two tank systems the conventional electric water
heater will be wired for electrical back-up. The solar
tank will serve solely as a storage tank and will not be
wired. After the circuit breaker has been turned off,
remove the access plate in the storage tank and de-
press the red reset button on the thermostat. If it
clicks when depressed the heating element should fire
immediately when you reconnect the circuit breaker. If
the reset button does not click and you do not have hot
water after one hour, the heating element or thermo-
stat may be defective. Contact you installation contrac-
tor for service.
10) SYSTEM COMPONENTS PARTS
See Figures 11, 12 and 13 for the location of the spe-
cific component numbered below.
1. SunEarth Solar Collector(s): Absorbs the sun’s
heat energy and transfers this heat to the heat ex-
change fluid (water) circulating through the collector.
2. Collector Sensor (T1): Wired to the control.
Works in conjunction with the tank sensor to automati-
cally turn your circulating pump on and off at preset
temperature differentials.
3. Tank Sensor (T2): Wired to your controller. Works
in conjunction with the collector sensor to turn your
circulating pump on and off at preset temperature dif-
ferentials.
4. Tank Outlet Sensor (T3) - Optional: Wired to
your controller, this sensor shows the temperature of
the hot water leaving the solar storage tank. This sen-
sor is for information purposes only, it does not affect