Special Applications

Combination Space Heating/Potable Water System

Some water heater models are equipped with inlet/outlet tappings suitable for combination water (potable) heating and space heating and not suitable for space heating applications only. If this water heater is to be used to supply both space heating and domestic potable (drinking) water, the instructions listed below must be followed.

•Be sure to follow the manual(s) shipped with the air handler system.

•This water heater is not to be used as a replacement for an existing boiler installation.

•Do not use with piping that has been treated with chromates, boiler seal or other chemicals and do not add any chemicals to the water heater piping.

•If the space heating system requires water tempera- tures in excess of 120°F, a mixing valve or an anti- scald device should be installed per its manufacturer’s instructions in the domestic (potable) hot water supply to limit the risk of scald injury.

•Pumps, valves, piping and fittings must be compatible with potable water.

•A properly installed flow control valve is required to pre- vent thermosiphoning. Thermosiphoning is the result of a continuous flow of water through the air handler circuit during the off cycle. Weeping (blow off) of the temperature and pressure relief valve (T & P) or higher than normal water temperatures are the first signs of thermosiphoning.

•The domestic hot water line from the water heater should be vertical past any mixing valve or supply line to the air handler to remove air bubbles from the sys- tem. Otherwise, these bubbles will be trapped in the air handler heat exchanger coil, reducing the efficiency.

•Do not connect the water heater to any system or components previously used with non-potable water heating appliances when used to supply potable water.

Some jurisdictions may require a backflow preventer in the incoming cold water line. This may cause the temperature and pressure relief valve on the water heater to discharge or weep due to expansion of the heated water. A diaphragm-type expansion tank suitable for potable water will normally eliminate this weeping condition. Please read and follow the manufacturer’s instructions for the installation of such tanks.

Also see “Water System Piping” section for additional instructions on the proper installation and operation of this water heater.

Figure 16
Typical Mixing Valve Installation
Combination Space Heating/Potable
Water Heating System		Must be vertical to
Domestic		remove air bubbles
Hot Water		Cold
Mixing	Out	Cold	Flow Control
Valve		Water	Valve
Hot		Inlet	Pump
Hot			In
Water			In
Water			Out
Out		To	Out
Out		To
Unions		Air
Unions		Handler	Coil
			Coil
		Discharge Pipe
		Do Not Cap or Plug
		Shut-off	Air
		Shut-off	Handler
		Valve	Handler
		Valve
		6" Maximum
		Air Gap
Metal Drain Pan Floor Drain			Massachusetts code
			does not allow this
			type of installation.

Solar Installation

If this water heater is used as a solar storage heater or as a backup for the solar system, the water supply temperatures to the water heater tank may be in excess of 120°F. A mixing valve or other temperature limiting valve must be installed in the water supply line to limit the supply temperature to 120°F. The unit must be set to Standard Mode (See Operating the Temperature Control System section).

NOTE: Solar water heating systems can often supply water with temperatures exceeding 180°F and may result in water heater malfunction.

318935-003 specifications

The American Water Heater 318935-003 stands out as a reliable option for residential and commercial hot water needs. Manufactured by American Water Heater Company, a brand known for its commitment to quality and innovation, this model integrates several advanced features and technologies to enhance efficiency, durability, and user experience.

One of the defining characteristics of the 318935-003 is its impressive efficiency rating. Designed with energy conservation in mind, it employs a highly efficient heating process that significantly reduces energy consumption. This not only helps in lowering utility bills for homeowners and businesses but also contributes to a more sustainable environment. The water heater meets or exceeds Energy Star guidelines, making it an eco-friendly choice.

The technology used in this model includes a state-of-the-art thermostat and advanced insulation material that ensures optimal heat retention. This dual approach minimizes heat loss, ensuring that hot water is readily available when needed while maintaining consistent temperatures. The adjustable thermostat allows users to customize settings to their preferences, thus improving comfort and efficiency.

Additionally, the 318935-003 features a robust design with high-quality materials that enhance its longevity. Its tank is constructed from durable steel, coated with a corrosion-resistant finish, which ensures that it withstands the test of time and minimizes maintenance needs. The unit is also equipped with a comprehensive safety system that includes a temperature and pressure relief valve, safeguarding against potential malfunctions.

The installation process of the American Water Heater 318935-003 is straightforward, making it accessible for both professionals and DIY enthusiasts. It is compatible with various plumbing systems and configurations, offering flexibility in installation locations. Maintenance is also user-friendly, with accessible components that allow for easy upkeep.

In summary, the American Water Heater 318935-003 embodies the ideal blend of efficiency, durability, and advanced technology. Its energy-efficient design, robust construction, and user-friendly features make it a top choice for anyone looking to fulfill their hot water requirements. Whether for a busy household or a commercial establishment, this water heater delivers consistent performance, ensuring a reliable supply of hot water year-round. Investing in the 318935-003 means investing in long-term satisfaction and efficiency, making it a wise addition to any space.