Water System Piping

Piping Installation

Piping, fittings, and valves should be installed according to the installation drawing (Figure 16). If the indoor installation area is subject to freezing temperatures, the water piping must be protected by insulation.

The water supply pressure should not exceed 80 psi. If this occurs, a pressure reducing valve with a bypass should 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 16. 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 mixing valve or an anti-scald device in the domestic hot water line as shown in Figure 17. 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 an expansion tank in the cold water line as specified under “Closed System/Thermal Expansion” section.

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.A temperature and pressure relief valve must be installed in the opening marked “Temperature and Pressure (T & P) Relief Valve” on the water heater. A discharge line must be added to the opening of the T&P Relief Valve. Follow the instructions under “Temperature and Pressure Relief Valve” section.

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 ex- cess 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 16

Water Piping Installation

	In a closed system use a
	thermal expansion tank
		Cold Water
Hot Water		Supply to Fixtures
Hot Water
Outlet		Main water supply
	Cold Water	Pressure reducing
	Cold Water	valve with bypass
	Inlet Valve	valve with bypass
	Inlet Valve
Union	Temperature and
	Pressure Relief Valve
	Discharge Pipe
	Do Not Cap or Plug
	Drain line 3/4”
	ID minimum
	6” Maximum
1”minimum	Air Gap
		Massachussetts:
Metal		Install a vacuum relief
Metal		in cold water line per
Drain Pan		in cold water line per
Drain Pan	Floor Drain section 19 MGL 142.
1 3/4” depth maximum	Floor Drain section 19 MGL 142.
Figure 17
Typical Mixing		Cold
Valve Installation		Water
Follow the mixing		Inlet
Follow the mixing
valve manufacturer’s
instructions.
Hot
Water
Outlet

Tempered water to fixtures

Mixing valve (Set to 120°F)