Bosch 830 ES Manual page 21

4.3.8 Fan speed adjustment
NOTICE: IMPORTANT INFORMATION!
▶ Natural gas heaters with installation altitudes below
2,000 ft above sea level disregard this section.
Installation adjustment:
After installing the tankless water heater, the fan speed values for
minimum power (P2) and maximum power (P1) may need adjustment
due to variations in altitude and vent pipe length. Failure to make
Altitude (above sea Total equivalent
level) vent length
0 - 2000 ft 3.5 - 32 ft
(0 - 610 m)
33 - 57 ft
2000 - 4500 ft 3.5 - 32 ft
(610 - 1372 m)
33 - 57 ft
4500 - 8000 ft 3.5 - 32 ft
(1372 - 2439 m)
33 - 57 ft
* Above 2000 ft, CO2 levels must be checked with a combustion gas analyzer, see section7.4 for instructions.
Table 23 Fan speed adjustment for 3" piping
1) Full equivalent length (inlet + outlet piping + fittings)
Altitude (above sea Total equivalent
level) vent length
0 - 2000 ft 2.25 - 59 ft
(0 - 610 m)
60 - 122.5 ft
2000 - 4500 ft 2.25 - 59 ft
(610 - 1372 m)
60 - 122.5 ft
4500 - 8000 ft 2.25 - 59 ft
(1372 - 2439 m)
60 - 122.5 ft
* Above 2000 ft, CO2 levels must be checked with a combustion gas analyzer, see section7.4 for instructions.
Table 24 Fan speed adjustment for 4" piping
1) Full equivalent length (inlet + outlet piping + fittings)
830 ES
Natural Gas
Minimum power Maximum power fan
1)
fan speed (P2) speed (P1)
7 No
modification required
8
8* 48*
8* 48*
9* 49*
9* 49*
Natural Gas
Minimum power Maximum power fan
1)
fan speed (P2) speed (P1)
7 No
modification required
8
8* 48*
8* 48*
9* 49*
9* 49*
necessary adjustments to fan speed values may result in improper
operation of the appliance.
First calculate the total equivalent vent length. This is the straight pipe
length of both exhaust and combustion air plus the number of elbows
used. To determine the length equivalency of each elbow refer to table 9.
Use the equivalent vent length value to determine the appropriate fan
speed values found in table 23 and 24. Refer to page 22 on how to adjust
the fan speeds if an adjustment is necessary. After changing fan speed
values, proceed to chapter 7.4 to confirm CO
specified ranges.
Liquid propane
Maximum power fan
speed (P1)
No
modification required
40*
41*
41*
41*
Liquid propane
Maximum power fan
speed (P1)
No
modification required
40*
41*
41*
41*
Installation instructions | 21
values are within
2
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 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
6 720 644 936 (2013/01)