Piping Installation - Rheem PVG Installation, Operation And Service Manual

WARNING
DISCHARGING WATER MAY BE HOT AND CAN CAUSE SCALD INJURIES
AND PROPERTY DAMAGE. DISCHARGE LINES MUST BE PROPERLY
INSTALLED AND PIPED TO AN ADEQUATE DRAIN.
CLOSED SYSTEM/THERMAL EXPANSION
Periodic discharge of the temperature and pressure relief valve may be due to
thermal expansion in a closed water supply system. The water utility supply
meter may contain a check valve, backflow preventer or water pressure
reducing valve. This will create a closed water system. During the heating
cycle of the water heater, the water expands causing pressure inside the water
heater to increase. The temperature and pressure relief valve may discharge hot
water under these conditions which results in a loss of energy and a build-up of
lime on the relief valve seat. To prevent this from happening, there are two
recommendations:
1.
Install a 125 PSI pressure relief valve in the cold water supply line. Make
sure the discharge of this valve is directed to an open drain and
protected from freezing.
2. Install a diaphragm-type expansion tank that is suitable for potable water
on the cold water supply line. The expansion tank must have a minimum
capacity of 1.5 U.S. gallons for every 50 gallons of stored water.
Contact the local water supplier or plumbing inspector for information on how
to control this situation. Do not plug the temperature and pressure relief valve.

PIPING INSTALLATION

Piping, fittings, and valves should be installed according to the installation
drawing (Figure 14). If the indoor installation area is subject to freezing
temperatures, the water piping must be protected by insulation.
Water supply pressure should not exceed 80% of the working pressure of the
water heater. The working pressure is stated on the water heater's data plate.
If this occurs a pressure limiting valve with a by-pass may need to be installed
in the cold water inlet line. This should be placed on the supply to the entire
house in order to maintain equal hot and cold water pressures.
IMPORTANT: Heat cannot be applied to the water fittings on the heater as
they may contain nonmetallic parts. If solder connections are used, solder the
pipe to the adapter before attaching the adapter to the hot and cold water
fittings.
IMPORTANT: Always use a good grade of joint compound and be certain that
all fittings are drawn up tight.
1. Install the water piping and fittings as shown in the Figure 14. Connect the
cold water supply (3/4 NPT) to the fitting marked "C". Connect the hot
water supply (3/4 NPT) to the fitting marked "H". Make sure the dip tube
is in the cold water fitting before connecting the hot and cold water lines.
(Note: 75T75 has 1"NPT)
IMPORTANT: Some models may contain energy saving heat traps to prevent
the circulation of hot water within the pipes. Do not remove the pink and blue
inserts within the heat traps.
2. Installation of unions in both the hot and cold water supply lines is
recommended for ease of removing the water heater for service or
replacement.
3. The manufacturer of this water heater recommends installing a tempering
valve or an anti-scald device in the domestic hot water line as shown in
Figure 15. These valves reduce the point of use temperature of the water
by mixing cold and hot water and are readily available for use. Contact a
licensed plumber or the local plumbing authority.
12
WATER SYSTEM PIPING (CONT.)
4. If installing the water heater in a closed water system, install a relief valve
5. Install a shutoff valve in the cold water inlet line. It should be located
6. Install a temperature and pressure relief valve and discharge line in the
7. After piping has been properly connected to the water heater, open the
or expansion tank in the cold water line as specified under "Closed
System/Thermal Expansion".
close to the water heater and be easily accessible. Know the location of
this valve and how to shut off the water to the heater.
opening marked "T & P RELIEF VALVE". Install as specified under
"Temperature and Pressure Relief Valve, pg. 11 ".
nearest hot water faucet and allow the tank to completely fill with water.
To purge the lines of any excess air and sediment, keep the hot water
faucet open for 3 minutes after a constant flow of water is obtained. Close
the faucet and check all connections for leaks.