Water System Piping
Piping Installation
Piping, fittings, and valves should be installed according
to the installation drawing (Figure 13). 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 bypass 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
Figure 13. 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 saving
heat traps to prevent the circulation of hot water within
the pipes. Do not remove the inserts within the heat
traps.
2.
The 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
14. These valves reduce the point-of-use
temperature of the water by mixing cold and hot
water and are readily available for use.
4.
If installing the water heater in a closed water
system, install a relief valve or expansion tank in
the cold water line as specified under “Closed
System/Thermal Expansion” (Page 13).
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 in
the opening marked “Temperature and Pressure
(T & P) Relief Valve” on the water heater. Add a
discharge line to the opening of the T & P relief
valve. Follow the instructions under “Temperature
and Pressure Relief Valve" (Page 14).
7.
After piping has been properly connected to the
water heater, remove the aerator at the nearest
hot water faucet. Open the hot water faucet and
allow the tank to completely fill with water. To
purge the lines of any excess air, 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.
Figure 14
Typical Tempering
Valve Installation
Follow the tempering
valve manufacturer’s
instructions.
Cold
Water
Inlet
Hot
Water
Outlet
Tempered water
to fixtures
Tempering valve
(Set to 120°F)
12
In a closed system use a
thermal expansion tank
Figure 13
Water Piping Installation
Main
Water
Supply
Cold Water
Inlet Valve
Cold Water
Supply to Fixtures
Hot Water
Outlet
Union
Temperature and
Pressure Relief Valve
Discharge line
6” maximum
above drain
Drain line
3/4” ID
minimum
Drain
Metal
Drain Pan
1 3/4” depth max.
1” min.
Massachusetts:
Install a vacuum relief
in cold water line per
section 19 MGL 142.
Pressure reducing
valve with bypass
