Closed System/Thermal Expansion - State Water Heaters FVIR Installation Instructions And Use & Care Manual

HOT WATER
OUTLET
1" MINIMUM
METAL
DRAIN PAN
SUITABLE DRAIN
FIGURE 16.
UNTEMPERED
HOT WATER
HOT
WATER
OUTLET
MIXING VALVE
(SET TO 120°F)
FOLLOW THE MIXING
VALVE MANUFACTURER'S
FIGURE 17.
IN A CLOSED SYSTEM USE A
THERMAL EXPANSION TANK
COLD WATER SUPPLY TO FIXTURES
PRESSURE REDUCING VALVE
WITH BYPASS
COLD WATER
INLET
COLD WATER INLET VALVE
(SHUT-OFF VALVE)
TEMPERATURE AND PRESSURE (T&P)
RELIEF VALVE NOT SHOWN)
DISCHARGE PIPE
(DO NOT CAP OR PLUG)
MASSACHUSETTS: INSTALL
A VACUUM RELIEF IN COLD
DRAIN LINE
WATER LINE PER SECTION
3/4" ID
19 MGL 142.
MINIMUM
6" MAXIMUM
AIR GAP
TEMPERED WATER
TO FIXTURES
COLD
WATER
INLET
INSTRUCTIONS
Please note the following:
• The system should be installed only with piping that is
suitable for potable (drinkable) water such as copper,
CPVC, or polybutylene. This water heater must not be
installed using iron piping or PVC water piping.
• Use only pumps, valves, or fittings that are compatible
with potable water.
• It is recommend that only full flow ball or gate valves
are used in water piping installations. The use of valves
that may cause excessive restriction to water flow is not
recommended.
• Use only 95/5 tin-antimony or other equivalent solder.
Any lead based solder must not be used.
• Piping that has been treated with chromates, boiler seal,
or other chemicals must not be used.
• Chemicals that may contaminate the potable water
supply must not be added to the piping system.

Closed System/Thermal Expansion

As water is heated, it expands (thermal expansion). In
a closed system, the volume of water will grow. As the
volume of water grows, 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 effects of
thermal expansion. Contact a plumbing service agency or
your retail supplier regarding the installation of a thermal
expansion tank.
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