Water System Piping
Piping Installation
Piping, fittings, and valves should be installed according to the installation drawing (Figure 2). 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
Figure 2
Water Piping Installation
Hot Water
Outlet
Union
In a Closed System use a
Thermal Expansion Tank.
Pressure Reducing
Valve With Bypass
| Main |
Cold Water | Water |
Inlet Valve Cold Water Supply | |
| Supply to |
| Fixtures |
Temperature and
Pressure Relief Valve
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.
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
Discharge line 6” maximum above drain
| Drain line |
| |
1” | 3/4” ID | Massachusetts: | |
minimum | |||
Min. | |||
Drain | Install vacuum relief | ||
| |||
| in cold water line per | ||
Drain Pan |
| section 19 MGL 142. | |
|
|
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 2. Connect the cold water supply (3/4 NPT) |
Figure 3
Tempering Valve
Side Connection
Follow the tempering
Hot
to the fitting marked “C”. Connect the hot water |
supply (3/4 NPT) to the fitting marked “H”. |
valve manufacturer’s instructions
Water Out
Important: Some models may contain energy saving 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 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 in the domestic hot |
Tempered water to fixtures
Tempering valve 
set to 120° F max.
Cold Water In
Figure 4
Tempering Valve
Cold
water line as shown in Figures 3 and 4. These |
valves reduce the |
hot water by mixing cold and hot water and are |
readily available. Contact a licensed plumber or the |
local plumbing authority. |
Top Water Connections
Follow the tempering valve manufacturer’s instructions
Water
Inlet
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". |
5. | Install a |
| 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. |
Hot
Water
Outlet
Tempered water to
fixtures
Tempering Valve (Set to 120° F)
5
