scope:

This standard is for water heaters that control the outlet temperature to specific limits and are installed within a hot water distribution system but not at point-of-use.

Description

A water heater (herein referred to as the "device") shall consist of a heat exchanger, a cold water inlet connection, a hot water outlet connection, and a means for precisely governing the outlet temperature. The device controller shall be listed to the appropriate electrical safety standard in accordance with the device category.

Maximum Working Pressure

The maximum working pressure of the device shall be at least 160 psi (1103 kPa) for devices in compliance with the ASME Boiler and Pressure Vessel Code, or at least 150 psi (1034 kPa) for devices in compliance with standards such as UL 174, UL 499, UL 1453, ANSI Z21.10.1 / CSA 4.1, or ANSI Z21.10.3 / CSA 4.3.

Inlet Water Temperature Range

The cold water inlet temperature range shall be 45°F to 105°F (7.2°C to 40.6°C).

Outlet Water Temperature Range

The device shall be capable of supplying the domestic hot water distribution system with a minimum adjustable hot water setpoint range of 105°F to 125°F (40.6°C to 51.7°C) when the incoming temperature is between 45°F and 105°F (7.2 °C and 40.6°C).

Maximum Flow Rates

The maximum flow rates of the device at given temperature rises shall be obtained from the device technical datasheet. The maximum flow rate at a +70°F (+39°C) temperature rise shall be included in the datasheet.

Compliance with Safety Standards

Devices shall conform to the safety requirements of the applicable water heater standards. Electrical controls shall comply and be categorized as operating controls with Class A control functions per UL 60730-1 and UL 60730-2-9, or comply with the applicable requirements of UL 499.

A list of non-mandatory recommended standards is given in Annex A.