Watter Saver HPWH500AAOC Installation, Operation And Maintenance Manual - page 6
MADE IN ROME, NY, USA
WATTERSAVER™ HEAT PUMP WATER HEATER
6
DISCHARGE/DRAIN LINES
• Must not be smaller than the pipe size of the relief
valve or drain stubs.
• Must not be capped, blocked, plugged or contain
any valve that obstructs flow to the drain.
• Must terminate a maximum of 6 inches above a floor
drain or external to the building provided the external
drainage is below the level of the WatterSaver™.
• Must be capable of withstanding 250° F without
distortion.
• Must be installed to allow complete drainage of the
T&P valve and discharge line.
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, water expands,
causing pressure inside the tank to increase. Under
these conditions, the T&P valve may discharge hot
water, resulting in a loss of energy and a build-up
of lime on the relief valve seat. To prevent this:
1. Install a diaphragm-type expansion tank that is
suitable for potable (drinking) water on the cold
water supply line. The expansion tank must have a
minimum capacity of 1.5 U.S. gallons per 50 gallons
of stored water.
2. 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.
IMPORTANT: Contact a local water supplier or
plumbing inspector for information on how to control
this situation. Do not plug the T&P valve.
Heat cannot be applied to the hot and
cold water connections as they may con-
tain non-metallic parts. If solder connec-
tions are used, solder the pipe to the
threaded adapter before attaching the
adapter to the hot and cold water con-
nections.
CAUTION
!
!
Piping, fittings, and valves should be in-
stalled according to the installation drawing
shown in Figure 3. If the indoor installation
area is subject to freezing temperatures, the
water piping must be protected by insula-
tion.
Water supply pressure should not exceed
80% of the unit’s working pressure (150
PSIG) as stated on the rating plate and on
Page 1 of this manual. If this occurs, a pres-
sure reducing valve with a by-pass may need
to be installed in the cold water supply line.
This should be placed on the supply to the
entire house in order to maintain equal hot
and cold water pressures.
PIPING INSTALLATION
FIGURE 3- Water Piping Installation
In a closed system use either a thermal expansion tank or pressure relief valve.
Pressure
Reducing
Valve
With
Bypass
Cold Water Inlet Valve
To
Additional
Cold Water
Taps
Hot Water Shutoff Valve
Thermal Expansion Tank
Cold Water Inlet From
Water Supply
Thermal Trap
Pressure Relief Valve
Thermal Trap
Hot Water
Oulet