Water System Piping
Piping, ﬁ ttings, and valves should be installed according to
the installation drawing (Figure 6). If the indoor installation
area is subject to freezing temperatures, the water piping
must be properly insulated.
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 bypass 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.
Heat must not 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
Always use a good grade of joint compound and be
certain that all fittings are tight.
1. Install the water piping and fittings as shown in Figure
6. 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".
IMPORTANT: Some models may contain energy sav-
ing heat traps to prevent the circulation of hot water
within the pipes. Do not remove these inserts.
2. The installation of unions in both the hot and cold
water supply lines are recommended for ease of
removing the water heater for service or replacement.
3. Some local codes may require, and 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 Figures 7 and 8. These valves reduce
the point-of-use temperature of the hot water by mixing
cold and hot water and are readily available. Contact
a licensed plumber or the local plumbing authority for
4. If installing the water heater in a closed water system,
install an expansion tank in the cold water line as
specified under "Closed System/Thermal Expansion."
5. Install a shut off valve in the cold water inlet line. It
should be located 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.
6. Install a temperature and pressure relief valve and
discharge line in the opening marked "T & P RELIEF
VALVE". Install as specified under "Temperature and
Pressure Relief Valve."
7. After piping has been properly connected to the water
heater, open the 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.
Water Piping Installation
2-1/2 Inch Depth Maximum
Side Water Connections
Follow The Tempering
Set To 120° F Maximum
Cold Water In
Top Water Connections
Follow the tempering
In a closed system use a
thermal expansion tank.
Pressure Relief Valve
6 Inches Maximum
3/4 Inch ID
Massachusetts: Install a
vacuum relief in cold water
line per section 19 MGL 142.
(Set To 120° F)