Rheem Power Direct Vent Series, Инструкция по использованию и уходу

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Thermal Expansion
Determine if a check valve exists in the inlet
water line. Check with your local water util-
ity company. It may have been installed in
the cold water line as a separate back flow
preventer, or it may be part of a pressure
reducing valve, water meter or water softener.
A check valve located in the cold water inlet
line can cause what is referred to as a “closed
water system”. A cold water inlet line with no
check valve or back flow prevention device is
referred to as an “open” water system.
As water is heated, it expands in volume and
creates an increase in the pressure within the
water system. This action is referred to as
“thermal expansion”. In an “open” water sys-
tem, expanding water which exceeds the capac-
ity of the water heater flows back into the city
main where the pressure is easily dissipated.
A “closed water system”, however, prevents
the expanding water from flowing back into
the main supply line, and the result of “thermal
expansion” can create a rapid and dangerous
pressure increase in the water heater and sys-
tem piping. This rapid pressure increase can
quickly reach the safety setting of the relief
valve, causing it to operate during each heating
cycle. Thermal expansion, and the resulting
rapid, and repeated expansion and contraction
of components in the water heater and piping
system can cause premature failure of the relief
valve, and possibly the heater itself. Replacing
the relief valve will not correct the problem!
The suggested method of controlling thermal
expansion is to install an expansion tank in
the cold water line between the water heater
and the check valve (see illustration on page
9). The expansion tank is designed with an air
cushion built in that compresses as the system
pressure increases, thereby relieving the over
pressure condition and eliminating the repeated
operation of the relief valve. Other methods of
controlling thermal expansion are also avail-
able. Contact your installing contractor, water
supplier or plumbing inspector for additional
information regarding this subject.
8
Installing the Water Heater
Corrosive Atmospheres
The air in beauty shops, dry cleaning
establishments, photo processing labs,
and storage areas for liquid and powdered
bleaches or swimming pool chemicals
often contain halogenated hydrocarbons.
An air supply containing halogenated
hydrocarbons may be safe to breathe,
but when it passes through a gas flame
corrosive elements are released that
will shorten the life of any gas burning
appliance.
Propellants from common spray cans
or gas leaks from A/C and refrigeration
equipment are highly corrosive after pass-
ing through a flame.
The water heater warranty is voided when
failure of the heater is due to operation in
a corrosive atmosphere.
NOTICE: The water heater
must not be installed near
an air supply containing
halogenated hydrocarbons.
Refer to the illustration below for suggested
typical installation. The installation of unions
or flexible copper connectors are recommended
on the hot and cold water connections so that
the water heater may be easily disconnected
for servicing if necessary. The HOT and COLD
water connections are clearly marked and are
3/4” NPT on all models. Install a shut-off valve
in the cold water line near the water heater.
Water Supply Connections
IMPORTANT: Do not apply
heat to the HOT or COLD
water connections. If sweat
connections are used, sweat
tubing to adapter before
fitting adapter to the cold
water connections on heater.
Any heat applied to the cold
water supply fittings will
permanently damage the
dip tube and heat traps.