Measuring Gas Pressure - Bosch GWH 715 ES Installation Instructions Manual

Installation instructions

3.12 Measuring gas pressure

Confirm gas pressure upon installation.
Connecting manometer
B Shut off gas supply at installer supplied shutoff valve
for this water heater.
B Remove front cover and locate inlet gas pressure
measuring point (see Fig. 34).
B Loosen screw inside left test point fitting (do not
remove) and connect manometer tube to test point.
Remove screw completely if correct size tapping is
available.
Static Pressure Test
B Turn gas supply back on.
B Record static gas pressure reading in table 13.
Operating Pressure Test
B Press ON/OFF button to turn off the appliance.
B Press and hold "Program" (P) button and press ON/
OFF button to turn appliance ON.
Fig. 33
B As soon as '188' is displayed, release "Program"
, button and the display should read P2.
B Press
or until P1 appears.
Note: While in this mode the appliance will run
constantly at maximum
maximum water flow.
For inlet gas pressure adjustment consider the
following table:
Gas type
p 4" WC
in
Table 12 Minimum inlet gas pressure under full operation
B Turn on high volume of hot water flow (at least 6
gpm) and heater will ignite. If heater display reverts to
P2, open more hot water fixtures to allow sufficient
flow. Press until P1 reappears on display.
B Operate all other gas appliances (except this heater)
on same gas piping system at maximum output.
24
power and allow
NG LPG
9" WC
B Record lowest operating gas pressure reading in
table 13.
Gas pressures lower than 4" W.C. for Natural Gas or 9"
W.C. for LPG will result in insufficient degree rise to the
hot water being used, reduced hot water volume,
possible error code faults and must be corrected. See
Gas Connections, chapter 3.6, page 10.
P1 fan speed:
Factory default: NG: 45, LP: 44
Lowering P1 fan speed reduces the maximum BTU
input.
As a temporary measure if the gas pressure in P1 is
below specification, lower P1 fan speed incrementally
until minimum inlet gas pressure reaches specified
range (table 12). After upgrading gas line, reset
appliance to P1 factory default setting (NG: 45, LP: 44).
Fig. 34 Gas pressure test port (left tapping)
Static Gas Pressure Reading (see Chapter 3.12)
enter here: ___________________ Date: ___________
Operating Gas Pressure Reading (see Chapter 3.12)
enter here: ___________________ Date: ___________
Table 13
HIGH ALTITUDE OPERATION (see chapter 6.4
page 30, for details)
Altitude above Natural
sea level Gas:
0 - 2,000 ft no
(0 - 610 m) modification
CO adjustment with flue
2
2,000 ft - 4,500 ft
gas analyzer required See
(610 m - 1,372 m)
section
Above 4,500 ft
(above 1,372 m)
Table 14
Liquid
Propane:
For operation at
elevations
no
above 2,000 ft
modification
(610 m) the
equipment
ratings shall be
reduced at the
rate of 4% for
each 1,000 ft
6.4
for instructions.
(305 m) above
sea level
Not approved
6 720 608 158