6
6 720 606 560
RELIEF VALVE
The listed pressure relief valve supplied must be installed
near the hot water outlet at time of installation of the heater.
No valve is to be placed between the relief valve and the
heater. A drain line must be connected to the relief valve to
direct discharge to a safe location. Do not install reducing
coupling or any other restriction in the discharge line. The
discharge line must be installed so as to allow complete
drainage of both the valve and the line. See figure 6.
GAS CONNECTION
Before connecting the gas supply to the heater check heater’s
model/rating plate to make sure that gas on which heater is
to operate is the same as specified on the model/rating plate.
The WR400-7.K.. instantaneous gas water heaters are
supplied with a gas pressure regulator that must be installed
on the heater before attaching the gas supply line, see figure
7. Failure to install the gas pressure regulator as show in
figure 7 will be a violation of A.G.A and C.G.A certification
of the unit.
BOSCH water heaters are shipped from the factory with
the gas pressure regulators preset for the gas shown on the
rating plate to the correct pressure:
-
in Canada, for high altitude operation;
-
in U.S., for standard altitude operation unless specially
marked as a high altitude unit.
Figure 7
GAS MANIFOLD PRESSURE TEST POINT
T
For measuring correct regulator operating pressure.
Check to make sure that the gas listed on the rating plate is
same as gas listed on the pressure regulator. See
PRESSURE REGULATION section of this manual for
information regarding gas pressure settings.
Note: Before attaching the gas supply line, be sure that all
gas pipe is clean on the inside. To trap any dirt or foreign
material in the gas supply line, a drip leg must be
incorporated in the piping. The drip leg must be readily
accessible and not subject to freezing conditions. Install
in accordance with the recommendations of serving
gas supplier.
Joint compounds (pipe dope) shall be applied sparingly and
only to the male threads of pipe joints. Do not apply
compound to the first two threads. The joint compound must
be resistant to the action of liquified petroleum gases.
Before placing water heater in operation check for gas
leakage.
Soap and water solution, or other material acceptable for
this purpose, shall be used in locating gas leaks. Matches,
candles, lighters, or other ignition sources shall not be used
for this purpose.
WARNING
The heater and its individual shutoff valve must be
disconnected from the gas supply piping system during any
pressure testing of the gas supply piping system at test
pressures in excess of 3,45 KPa (½ psig).
The water heater must be isolated from the gas supply piping
system by closing its individual manual shutoff valve during
any pressure testing of the gas supply piping system at test
pressures equal to or less than 3,45 KPa (½ psig).
The water heater, including the pressure regulator provided
with it, must not be operated at gas supply pressures in
excess of 3,45 KPa (½ psig). If overpressure has occurred
such as trough improper testing of the gas lines or emergency
malfunction of the supply system, the gas valve and regulator
must be checked for safe operation. Make sure that the
outside vent valves are protected against blockage. These
are part of the gas supply system, not the water heater.
Vent blockage may occur during ice storms.
Figure 7 a)
Gas Burner
test point
D
for measuring pressure at full flow and input
Figure 6
GAS INLET PIPE
PRESSURE TAP
PRESSURE REGULATOR
T
G662_042
