Bosch SST150-40 Installation And Operating Manual page 14

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).
Figure 4-1 Drain valve installed
1 4 |
DRAIN
VALVE
Temperature & Pressure (T&P) Relief Valve
WARNING:
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 (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.
Indirect Fired Water Heaters Installation and Operating Manual