8
WARNING
Explosion Hazard
If the temperature and pressure relief
valve is dripping or leaking, have a
qualified person replace it.
Examples of a qualified person include:
licensed plumbers, authorized gas
company personnel, and authorized
service personnel.
Do not plug valve.
Do not remove valve.
Failure to follow these instructions can
result in death or explosion.
FIGURE 11
TEMPERATURE AND PRESSURE
RELIEF VALVE INSTALLATION
TEMPERATURE AND
PRESSURE RELIEF
VALVE
DISCHARGE LINE
3/4 INCH MIN.
DO NOT CAP OR PLUG
6 INCH
MAXIMUM
AIR GAP
DRAIN PAN
DRAIN
Closed System/Thermal Expansion
As water is heated, it expands (thermal expansion). In a
closed system, the volume of water will increase. As the
volume of water increases, there will be a corresponding
increase in water pressure due to thermal expansion.
Thermal expansion can cause premature tank failure
(leakage). This type of failure is not covered under the
limited warranty. Thermal expansion can also cause
intermittent temperature-pressure relief valve operation:
water discharged from the valve due to excessive
pressure build up. The temperature-pressure relief
valve is not intended for the constant relief of thermal
expansion. This condition is not covered under the limited
warranty.
A properly-sized thermal expansion tank should be
installed on all closed systems to control the harmful
effects of thermal expansion. Contact a plumbing service
agency or your retail supplier regarding the installation of
a thermal expansion tank.
Do not plug the temperature and pressure relief
valve.
Solar Control Systems
Solar control systems used with this solar storage tank
must not allow temperatures in the tank to exceed 180°F
and must protect the system from freeze damage when
the temperatures approach freezing.
This solar storage tank does not contain a heat
exchanger; therefore, only potable (drinkable) water may
be allowed to enter the tank. If this solar storage tank is
installed in a system using any heat transfer
fl
uid other
than potable water, a separate heat exchanger must be
installed. Heat exchangers used in conjunction with this
solar storage tank must provide adequate protection of
contamination of potable water by toxic
fl
uids used in
heat exchange systems.
If this water heater is used as a solar storage heater or as
a backup for the solar storage system, the water supply
temperatures to the water heater tank may be in excess
of 120°F. A mixing valve or other temperature limiting
device should be installed in the water supply line to limit
the supply temperature to 120°F.
Temperature and Pressure Relief Valve
For protection against excessive pressures and
temperatures, a temperature and pressure relief valve must
be installed in the opening marked “T & P RELIEF VALVE”
(See Figure 11).
Caution: To reduce the risk of excessive pressures and
temperatures in this solar storage tank water heater,
install temperature and pressure relief protective
equipment required by local codes, but no less than
a combination temperature and pressure relief valve
certi
fi
ed by a nationally recognized testing laboratory that
maintains periodic inspection of the production of listed
equipment or materials, as meeting the requirements
for Relief Valves and Automatic Shutoff Devices for Hot
Water Supply Systems, ANSI Z21.22 - current edition.
