Fan Speed - Bosch 940 ESO Installation Manual

8.8

Fan speed

8.8.1 Fan speed adjustment
IMPORTANT! Installation adjustment:
After installing the water heater, the fan speed values for
minimum power (P2) and maximum power (P1) may
need adjustment due to variations in altitude.
Failure to make necessary adjustments to fan speed
values may result in improper operation of the
appliance.
Fan speed adjustment
Altitude Minimum power
(above sea fan speed (P2)
0 - 2000 ft
(0 - 610 m)
2000 - 4500 ft
(610 - 1372 m)
4500 - 8000 ft
(1372 - 2439 m)
* Above 2000 ft, CO levels must be checked with a combustion gas analyzer, see section
2
Table 5 Fan speed adjustment
Adjusting minimum power fan speed (P2)
To select fan speed:
B Press ON/OFF button into OFF.
B Press and hold "Program" button
ON/OFF button to turn appliance ON.
Fig. 51
B As soon as '188' is displayed, release "Program"
button , and the display should read P2.
B Press or to choose the fan speed suitable
with your installation, see Table 5.
B Press and hold (± 5 sec.) "Program" button
the display flashes, then the selected value is memo-
rized.
Do not set P2 to greater then 9.
i
6 720 644 956
Natural Gas
Maximum power fan
speed (P1)
No
7
modification required
8* 48*
9* 49*
and press
until
Use the equivalent vent length value to determine the
appropriate fan speed value found in the Table 5. Refer
to page 29 on how to adjust the fan speeds if an
adjustment is necessary. After changing fan speed
values, proceed to section 9.4 to confirm CO2 values
are within specified ranges.
Liquid propane
Maximum power fan
speed (P1)
No
modification required
47*
48*
9.4
Adjusting maximum power fan speed (P1)
To select fan speed:
B Press ON/OFF button into OFF.
B Press and hold "Program" button
ON/OFF button to turn appliance ON.
Fig. 52
B As soon as '188' is displayed, release "Program" but-
ton , and the display reads P2.
B Press the minus button
B Press "Program" button
The current setting will appear on the display.
B Press or to choose the fan speed suitable
with your installation, see Table 5.
B Press and hold (± 5 sec.) "Program" button
the display flashes, then the selected value is memo-
rized.
Proceed directly to Section 9.4 to confirm
i
CO values are within range.
2
Operation instructions
For operation at elevations above 2,000
ft (610 m) the equipment ratings shall
be reduced at the rate of 4% for each
1,000 ft (305 m) above sea level
for instructions.
and press
to display P1.
to enter P1 adjustment.
until
29