Specifications

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Indirect Fired Water Heaters Installation and Operating Manual
Installation & Operating Manual
Anti-scald Valves (Mixing Valves)
Anti-scald valves used with water heaters are also called
tempering valves or mixing valves. An anti-scald valve
mixes cold water in with the outgoing hot water to assure
that hot water reaching a building fi xture is at a
temperature low enough to be safe.
Usually, the maximum temperature of the outlet water will
stay near the setting of the tank control. In some cases,
however, hot water usage patterns can cause the outlet
water temperature to rise signifi cantly above the control
setting.
The temperature of water going to the fi xtures may be
more carefully controlled through the use of a
thermostatic mixing valve. This device blends a controlled
amount of cold water with the hot water leaving the tank
so that water at a more constant temperature exits the
mixing valve. Anti-scald mixing valve piping is illustrated in
FIG.’s 3-1 thru 3-4.
WARNING:
 An anti-scald mixing valve does not
eliminate the risk of scalding.
– Set the tank thermostat as low as
practical.
– Feel water before bathing or showering.
– If anti-scald or anti-chill protection is
required, use devices specifi cally
designed for such service. Install
these devices in accordance with their
manufacturer’s instructions.
Install Drain Valve
Drain valve and fi ttings are supplied by others.
Standard Installation
• Install a tee connection at the domestic cold water inlet
(FIG. 4-1).
DRAIN
VALVE
Figure 4-1 Drain valve installed
Temperature & Pressure (T&P) Relief Valve
WARNING:
 For protection against excessive
temperatures andpressure, install
temperature and pressureprotective
equipment required by local codes, butnot
less than a combination temperature and
pressure (T&P) relief valve certifi ed by a
nationally recognized testing laboratory that
maintains periodic inspection of production
of listed equipment or materials as meeting
the requirements for Relief Valves and
Automatic Gas Shutoff Devices for Hot
Water Supply Systems, ANSI Z21.22 and the
Standard CAN1-4.4, Temperature, Pressure,
Temperature and Pressure Relief Valves
and Vacuum Relief Valves. The combination
temperature and pressure relief valve shall
be marked with a maximum set pressure not
to exceed the maximum working pressure
of the water heater. The combination
temperature and pressure relief valve shall
also have an hourly rated temperature
steam BTU discharge capacity not less than
shown in Table 4A.
Install the combination temperature and
pressure relief valve into the opening
provided and marked for this purpose on
the water heater. Failure to properly install
the correct temperature and pressure (T&P)
relief valve can result in a discharge of hot
water that can cause severe personal injury
or substantial property damage.
NOTICE:
 Verify that the combination temperature and
pressure (T&P) relief valve complies with
local codes. If the combination temperature
and pressure relief valve does not comply
with local codes, replace it with one that
does. Follow the installation instructions in
this section.