Water System Piping, Piping Installation

Water System Piping

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 properly insulated.

Water supply pressure should be 50-60 PSIG and not exceed the maximum 80 PSIG. If the supply line pressure exceeds 80 PSIG, a pressure reducing valve (PRV) with a bypass should 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 must not 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.

•Always use a good grade of joint compound and be certain that all fittings are tight.

IMPORTANT: DO NOT over apply joint compound.

Piping Installation

1.Install the water piping and fittings as shown in Figure 4. Connect the cold water supply (3/4” NPT) to the fitting marked “Cold”. Connect the hot water supply (3/4” NPT) to the fitting marked “Hot”.

2.The installation of unions in both the hot and cold water supply lines are recommended for ease of removing the water heater for service or replacement.

3.Some local codes may require, and 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 4. These valves reduce the point-of-use temperature of the hot water by mixing cold and hot water and are readily available. Contact a licensed plumber or the local plumbing authority for more information.

4.Some local codes may require, and the manufacturer of this water heater recommends, installing a pressure reducing valve (PRV) in the cold water inlet line where it enters the residence as shown in Figure 4.

5.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.”

6.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.

7.Install a discharge line from the temperature and pressure relief valve in the opening marked “T & P RELIEF VALVE”. See Figure 5 and the “Temperature and Pressure Relief Valve” section.)

8.After piping has been properly connected to the water heater, open the nearest hot water faucet. Then open the cold water shut off valve 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.

Figure 4

Water Piping Installation with Mixing Valve

	Heat Trap - The top of the heat trap	Massachusetts: Install a vacuum relief in cold
	must be higher than the storage tank	water line per section 19 MGL 142.
	of the water heater.
	of the water heater.	Vacuum Relief Valve
		Vacuum Relief Valve

Temperature and Pressure Relief Valve

Discharge Pipe

(Do Not Cap or Plug)

Union

Shut-off Valve (Hot)

Untempered Water Outlet

Hot

(Outlet) Mixing Valve (Optional) - Follow the Mixing Valve’s Manufacturer’s Installation

Instructions. (Set to 120° F)

Tempered Water to Fixtures Condensate Drain Lines*

Cold Water Outlet

Cold Water

Inlet Valve

Cold Water

Inlet

Whole House Pressure Reducing Valve (PRV) should be installed where the water supply enters the residence.

Metal Drain Pan 2 1/2”
Depth Maximum and
2 Inches wider than	Cold
the water heater.	(Inlet)
		Shut-off Valve
		(Cold)
Drain Line 3/4”	Drain	6” Maximum
ID Minimum	Drain	Air Gap
ID Minimum		Air Gap

In a closed system, use a thermal expansion tank. See “Closed System/ Thermal Expansion” section.

*If an adequate drain is not available for the condensate drain lines then a condensate pump should be used. DO NOT discharge the condensate drain lines into the metal drain pan.

318257-000, PHPT-80 specifications

The A.O. Smith PHPT-80,318257-000 is a highly efficient water heater designed to meet the needs of both residential and commercial applications. This unit features a capacity of 80 gallons, making it suitable for larger households and businesses requiring a significant supply of hot water. The PHPT-80 stands out for its innovative technologies, versatility, and durability.

One of the key features of the PHPT-80 is its high energy efficiency. This model utilizes advanced insulation technology that minimizes heat loss, making it an excellent choice for energy-conscious consumers. In addition, the heater is equipped with a powerful and efficient heating element that ensures rapid recovery times, allowing for a continuous supply of hot water even during peak usage periods.

The PHPT-80 also incorporates a user-friendly digital display that provides real-time information about the unit's performance. This feature enables users to monitor water temperature settings, energy usage, and maintenance alerts, enhancing convenience and ensuring optimal operation. Furthermore, the heater includes a self-diagnostic system that assists in troubleshooting and ensures that the system runs smoothly.

Safety is another critical aspect of the design of the A.O. Smith PHPT-80. It includes a comprehensive set of safety features such as a temperature and pressure relief valve, an over-temperature protection system, and a flame arrestor. These features help minimize the risk of accidents and ensure peace of mind for users.

Constructed with high-quality materials, the PHPT-80 boasts durability and longevity. Its tank is lined with a corrosion-resistant coating and insulated to protect against external elements and prolong its lifespan. Additionally, it features a robust commercial-grade thermostat that allows for precise temperature control.

A.O. Smith's commitment to sustainability is also reflected in the PHPT-80. The unit is designed to be eco-friendly, contributing to lower utility bills and reduced environmental impact. The heater complies with stringent industry standards, making it a responsible choice for consumers looking to reduce their carbon footprint.

With its blend of energy efficiency, advanced technology, user-friendly features, and robust safety mechanisms, the A.O. Smith PHPT-80,318257-000 water heater represents a reliable solution for those in need of a high-capacity hot water supply. Whether for residential or commercial use, this model delivers exceptional performance and reliability, making it a top choice among water heater options.