1 4
|
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 fixture 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 significantly above the control
setting.
The temperature of water going to the fixtures 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.
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 specifically designed for such service. Install
these devices in accordance with their
manufacturer’s instructions.
WARNING
Install Drain Valve
Drain valve and fittings 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
For protection against excessive temperatures and
pressure, install temperature and pressure
protective equipment required by local codes, but
not less than a combination temperature and
pressure relief valve certified 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.
WARNING
Verify that the combination temperature and pressure
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.
NOTICE
