Index
WATER SYSTEM PIPING
Piping Installation
Piping, fittings, and valves should be installed according to the installation drawing (Figure 4). 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 work- ing pressure of the water heater. The working pressure is stated on the water heater’s data plate. If this occurs, a pressure reducing valve with a bypass should be installed in the cold water inlet line to the entire system. This should be placed on the supply to the entire structure in order to maintain equal hot and cold water pressures.
Note: Water supplied to the unit that exceeds 12 grains (205 mg/l) total hardness may reduce the life and perform- ance of the water heater. Depending on the degree of hard- ness, it is recommended that either a water
Important: Heat cannot be applied to the water fittings on the water 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 fit- tings.
1.The water heater may have three water piping connec- tion points. The top and front are 1 1/2” NPT and the connections on the back of some heaters are 2” NPT. When using front or back connections a nipple inlet tube combination is required. For availability contact
Note: Inlet and outlet piping connections cannot be mixed. For example, a top inlet connection must use a top outlet connection.
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.Since most commercial installations utilize higher temperatures, the use of a tempering valve is strongly recommended in all domestic hot water lines (i.e. public restroom sinks, etc).
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” (Page 12).
5.Install a
6.The water heater is shipped with a
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.
10
Space Heating
If this unit is to be used to supply both space heating and domestic potable (drinking) water then the following instructions must be followed:
1.All piping and components used must be suitable for use with domestic (potable) drinking water.
2.Do not use piping or components that have been connected to a nonpotable system or treated with chromates or other toxic chemicals. Do not add any chemicals to the water heater piping.
3.If system requires temperatures in excess of 120°F (49°C) install a tempering valve, per the manufacturers instructions, in the domestic (potable) hot water line to limit the risk of scalding (See Figure 5).
4.Be sure to follow the manual(s) shipped with the heating system. Also follow any state or local codes.
Figure: 4 Water Piping Installation
| In a closed system use a | |
| Thermal Expansion Tank | |
|
| Cold Water |
Hot Water |
| Supply to Fixtures |
| Main Water | |
Outlet |
| |
| Supply | |
|
| |
|
| Pressure Reducing |
Unions | Cold Water Valve with Bypass | |
| Inlet Valve |
|
| Temperature and |
|
| Pressure Relief Valve | |
| Discharge line |
|
| 6” max. above |
|
| drain |
|
Metal drain | Drain line | Massachusetts: |
pan 1 3/4” | 3/4” ID min. | Install a vacuum relief |
depth max. |
| in cold water line per |
| Drain | |
| section 19MGL 142 | |
|
| |
Tempering Valve Installation
A Tempering Valve should be installed per the manufac- turer’s instructions in the hot water line. See Figure 5 (below) for sample tempering valve installation.
Figure 5: Tempering Valve
Cold
Water
Inlet
Follow the tempering valve manufacturer’s instructions.
Hot
Water
Outlet
Tempered water to fixtures
Tempering valve (Set to 120°F)