Water Supply Connections - Rheem PowerVent Series Use & Care Manual

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.
NOTICE: The Canadian
Standards Association
mandates a manual
gas shut off valve: See
CSA B149- Installation
Code for complete
instructions. Local codes
or plumbing authority
requirements may vary
from the instructions or
diagrams provided and
take precedent over these
instructions.
Thermal Expansion
Determine if a check valve exists in the inlet
water line. Check with your local water
utility 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
system, expanding water which exceeds the
capacity 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

Water Supply Connections

Refer to the illustration below for suggested
typical installation. The installation of unions
or flexible copper connectors is recommended
on the hot and cold water connections so that
the water heater may be easily disconnected
Typical Installation
Heat trap
6" minimum
Hot water outlet to
fixtures
Water Heater Jacket
Temperature and
pressure relief valve
Remote Control
(Factory Installed Option)
Manual gas shut-off
To gas supply
Ground joint union
Sediment trap
Cap
Thermostatic gas valve
Jacket door
Flammable Vapor Sensor
Auxiliary catch pan
pressure increase in the water heater and
system 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 below).
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
available. Contact your installing contractor,
water supplier or plumbing inspector for
additional information regarding this subject.
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.
Vent connector
Union
Shut-off
valve
Thermal expansion
tank (if required)
Drain
valve
Drain Pan Pipe
to suitable drain.
1/4" per foot maximum slope up or
down for horizontal venting.
Anode
Blower assembly
Transformer Box
(Remote Control Models Only)
Union
Heat trap
6" minimum
To cold water
supply
Shut-off valve
Relief valve discharge
line to suitable open
drain.
Combustion Air
Inlet Openings
6" Air gap
9