Bosch C 950 Installation Manual page 22

22 | Installation instructions
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
C1050ES Fan Speed Adjustment
Altitude (above sea Vent
level) terminal
0 - 2000 ft Twin
(0 - 610 m) system
2)
2000 - 4500 ft Twin
(610 - 1372 m) system
Table 28 C1050ES Fan speed adjustment for 2" piping
1) Full equivalent length (inlet + outlet piping + fittings)
2) When installing in altitude, the unit may not reach the rated Input
3) When adjusting the unit, CO2 levels must be checked with a combustion gas analyzer, see chapter 7.5 for instructions.
Altitude (above sea Vent
level) terminal
0 - 2000 ft Concentric
(0 - 610 m)
Twin
system
2000 - 4500 ft Concentric
(610 - 1372 m)
Twin
system
4500 - 8000 ft Concentric
(1372 - 2439 m)
Twin
system
* Above 2000 ft, CO2 levels must be checked with a combustion gas analyzer, see chapter 7.5 for instructions.
Table 29 C1050ES Fan speed adjustment for 3" piping
1) Full equivalent length (inlet + outlet piping + fittings)
6 720 805 440 (2014/11)
Natural Gas
Minimum
Total equivalent vent
power fan
1)
length
speed (P2)
3.5 - 11 ft 12
12 - 19 ft 12
3.5 - 11 ft 13
12 - 19 ft 13
Natural Gas
Minimum
Total equivalent vent
power fan
1)
length
speed (P2)
6 - 25 ft
26 - 46 ft
6 - 37 ft
38 - 62 ft
6 - 25 ft 11*
26 - 46 ft 11*
6 - 37 ft 10*
38 - 62 ft 11*
6 - 25 ft 11*
26 - 46 ft 13*
6 - 37 ft 11*
38 - 62 ft 12*
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 tables
9 and 10.
Use the equivalent vent length value to determine the appropriate fan
speed values found in table 29 and 30. Refer to page 25 on how to adjust
the fan speeds if an adjustment is necessary. After changing fan speed
values, proceed to chapter 7.5 to confirm CO
specified ranges.
Liquid
propane Natural Gas
Minimum Maximum
power fan power fan
speed (P2) speed (P1)
3) 3)
17 52
3) 3)
17 52
3) 3)
17 52
3) 3)
17 52
Liquid
propane Natural Gas
Minimum Maximum
power fan power fan
speed (P2) speed (P1)
No modification required on installations below 2000 ft Altitude
14*
14*
13*
14*
14*
16*
14*
15*
values are within
2
Liquid
propane
Maximum
power fan
speed (P1)
3) 3)
52
3) 3)
52
3) 3)
52
3) 3)
52
Liquid
propane
Maximum
power fan
speed (P1)
52* 52* For operation at
elevations above
53* 53*
2,000 ft (610 m)
52* 52*
the equipment
53* 53*
ratings shall be
reduced at the rate
53* 53*
of 4% for each
53* 53*
1,000 ft (305 m)
53* 53*
above sea level
53* 53*
Greentherm