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.
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.
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.
Figure 13
Water Piping Installation
Hot Water
Outlet
Union
In a closed system use a 
thermal expansion tank
Cold Water
Supply to Fixtures
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| Water |
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| Supply |
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Cold Water |
| Pressure reducing | ||||||
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Inlet Valve |
| valve with bypass | ||||||
Temperature and
Pressure Relief Valve
Discharge line 6” maximum above drain
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 |
| in the domestic hot water line as shown in Figure 14. |
| These valves reduce the |
| 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. |
5. | Install a |
| should be located close to the water heater and be |
1”minimum
Metal 
Drain Pan
1 3/4” depth maximum
Figure 14
Typical Tempering
Valve Installation
Follow the tempering valve manufacturer’s instructions.
Hot
Water
Outlet
Drain line 3/4” ID minimum
Drain
Massachusetts: Install a vacuum relief in cold water line per section 19 MGL 142.
Cold
Water
Inlet
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. |
Tempered water to fixtures
Tempering valve (Set to 120°F)
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