ECR International
7
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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 (15 cm) above
a floor drain or external to the building provided the
external drainage is below the level of the Watter$aver.
• Must be capable of withstanding 250° F (121.1° C)
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,
use one of the following two methods
:
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 (5.7 liters) per 50 gallons
(189.3 liters) of stored water.
2. Install a 125 PSI (861.8 kPa) 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.
PIPING INSTALLATION
Piping, fittings, and valves should be installed
according to the installation drawing shown in
Figure 3
.
If the indoor installation area is sub-
ject to freezing temperatures, the water piping
must be protected by insulation.
Water supply pressure should not exceed 80%
of the unit’s working pressure (150 PSIG) as
stated on the rating plate and in the specifica-
tion section of this manual. If this occurs, a
pressure 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.
CAUTION
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 connec-
tions.
IMPORTANT:
Always use a good grade
of joint compound and be certain that all
fittings are drawn up tight.
Figure 3
Recommended Water Piping
In a closed system use
either
a thermal expansion tank
or
pressure relief valve.
Pressure
Reducing
Valve
With
Bypass
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
NOTE:
Refer to local plumb-
ing codes for correct and
safe operation of the
Watter$aver Heat Pump
Water Heater.
Vacuum Relief
Valve
Cold Water Inlet Valve
Hot Water
Outlet
This illustration does not
meet the code requirements
of the Commonwealth of
Massachusetts.
