HTP Drain Back, Installation, Start-Up, Maintenance, Parts, Warranty

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lp-585 Rev. 000 Rel. 001 Date 9.10.18
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System Fill Valve (Valve #8)
Fills the system with HTF. Also eliminates air from the system.
Expansion Tank
Precharged with air to allow for the expansion and contraction of
HTF.
Drain Valve (Valve #10)
Used to charge the collector loop with glycol, purge air from the
loop and drain the solar water heater heat exchanger of fluid.
Collector Isolation Valve (for system fill) (Valve #11)
Used to direct the flow of HTF and to pressurize and eliminate air
from the solar system.
Ball Valve (for circulator) Valve #12
Used to isolate the circulator pump for service. Close both ball valves
to isolate pump.
Circulator (#13)
Circulates the HTF from the solar collector into the solar heat
exchanger.
Drain Valve (Tank) (Valve #14)
Flushes sediment which may accumulate on the bottom of the solar
water heater and also provides a means of draining the tank.
Tank Sensor
Is wired to the solar controller to measure the temperature on the
bottom of the solar water heater in conjunction with the solar
collector sensor. Turns the circulating pump on and off at the solar
control preset temperature differentials.
Solar Controller
The solar controller turns the circulator on or off depending on heat
gained from solar operation. The controller also limits overheating
in the solar water heater. Some controllers have various options.
The controller should always be set in the “auto” position so that it
operates the array automatically when there is solar energy to be
collected.
Solar Heat Exchanger
The solar heat exchanger has an integral finned tube designed to
transfer heated energy rapidly from the solar collector into potable
water. The heat exchanger is constructed for superior corrosion
resistance and long-term reliability.
Hot Water Outlet
Each solar water heater has a hot water dip tube outlet which draws
water from the top of the heater. This helps to keep heat trapped
inside the highly insulated storage tank.
Solar Tank Temperature and Pressure Relief Valve
The relief valve must comply with standards for relief valves (ANSI
Z21.22) by a nationally recognized lab that maintains periodic
inspections of production listed equipment. No valve of any type
should be installed between the relief valve and tank. Local codes
govern installation of relief valves.
The relief valve outlet must be piped to a suitable open drain so that
the discharge water cannot contact live electric parts to eliminate
potential damage. Piping used should be approved for hot water
distribution. The discharge line must be no smaller than the outlet
of the relief valve and must pitch downward to allow complete
drainage. The end of the discharge piping should not be threaded
or concealed and must be protected from freezing. No valve of
any type, restriction or reducer coupling should be installed in the
discharge line.
Mixing Valve (Rated ASSE 1017) REQUIRED PER SRCC OG-300
Automatically blends hot and cold water feed lines to control
discharge to an acceptable and safe temperature. This also increases
the amount of hot water drawn from the solar water heater by
not allowing incoming cold water to fully temper the hot water
stored inside the tank. To help prevent injury due to scalding, it is
recommended that the mixing valve be set at 120
o
F.
Ball Valve (for cold water shut-off) (Valve #24)
The cold water shut off valve should be used in the event of an
emergency shutdown.
It is very important that you do the potable piping before you pipe
into the solar system. Failure to do so may damage your water heater.
Improper installation IS NOT covered by warranty.
Never use dielectric unions or galvanized steel fittings on any
domestic water connections or auxiliary connections. ONLY use
copper or brass fittings. Teflon thread sealant must be used on all
connections.
E. Installation of the Drain Back Tank
1. Pipe solar collector return to the inlet fitting located on the top
of the drain back tank.
2. Pipe drain back tank outlet (located near the bottom of the tank)
to the solar heat exchanger inlet.
3. Pipe solar heat exchanger outlet to the solar collector supply
fitting.
(See installation diagrams in Part 5 for piping details.)
Insulate all hot water lines, as well as the final 5’ of cold water supply
pipe leading to the system, with at least ¾” thick heat resistant rubber
tubing insulation.
Before commissioning the system, install the sight tube and an ASME/
ANSI rated 30 PSI pressure relief valve into the appropriate fittings on
the drain back tank using pipe dope. Follow further pressure relief
valve installation information listed below.
To avoid water damage or scalding due to relief valve operation:
• Discharge line must be connected to relief valve outlet and
run to a safe place of disposal. Terminate the discharge line
in a manner that will prevent possibility of severe burns or
property damage should the relief valve discharge.
• Discharge line must be as short as possible and the same
size as the valve discharge connection throughout its entire
length.
• Discharge line must pitch downward from the valve and
terminate at least 6” above the floor drain, making discharge
clearly visible.
• The discharge line shall terminate plain, not threaded, with
a material serviceable for temperatures of 375
o
F or greater.
• Do not pipe discharge to any location where freezing could
occur.
• No valve may be installed between the relief valve and heater
or in the discharge line. Do not plug or place any obstruction
in the discharge line.
• Test the operation of the relief valve after filling and
pressurizing the system by lifting the lever. Make sure the
valve discharges freely. If the valve fails to operate correctly,
immediately replace with a new, properly rated relief valve.
• Test relief valve at least once annually to ensure the waterway
is clear. If valve does not operate, turn the heater “off”
and call
a plumber immediately .
• Take care whenever operating relief valve to avoid scalding
injury or property damage.
FAILURE TO COMPLY WITH THE ABOVE GUIDELINES COULD
RESULT IN FAILURE OF RELIEF VALVE OPERATION, RESULTING
IN POSSIBILITY OF SUBSTANTIAL PROPERTY DAMAGE, SEVERE
PERSONAL INJURY, OR DEATH.