Bosch 940 ES Installation And Operating Instructions Manual page 31

Altitude (above Total equivalent
sea 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 section 7.4 for instructions.
1) Full equivalent length (inlet + outlet piping + fittings)
Table 23 Fan speed adjustment for 3" piping
Altitude (above Total equivalent
sea 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 section 7.4 for instructions.
1) Full equivalent length (inlet + outlet piping + fittings)
Table 24 Fan speed adjustment for 4" piping
940 ES – 6 720 644 930 (2019/09)
Natural Gas
Minimum Maximum
1)
power fan power fan
speed (P2) speed (P1)
7 No
modification
required
8
8* 54*
8* 55*
9* 55*
9* 55*
Natural Gas
Minimum Maximum power
1)
power fan fan speed (P1)
speed (P2)
7 No
modification
required
8
8* 54*
8* 55*
9* 55*
9* 55*
Liquid propane
Maximum
power fan speed
(P1)
No
modification
required
47*
48*
48*
49*
Liquid propane
Maximum
power fan
speed (P1)
No
modification
required
47*
48*
48*
49*
Adjusting minimum power fan speed (P2)
To select fan speed:
▶ Push power button
Installation 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 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
to shut the water heater off.
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