6 720 644 930
20
Installation instructions
3.3.8
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 and vent pipe length.
Failure to make 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 6.
Use the equivalent vent length value to determine the appropriate fan speed values found in Table 20 and 21. Refer
to page 21 on how to adjust the fan speeds if an adjustment is necessary. After changing fan speed values, proceed
to section 6.4 to confirm CO2 values are within specified ranges.
Fan speed adjustment
Natural Gas
Liquid propane
Altitude
(above sea
level)
Total
equivalent
vent length
1)
1)
Full equivalent length (inlet + outlet fittings)
Minimum
power fan
speed (P2)
Maximum
power fan speed
(P1)
Maximum
power fan speed
(P1)
0 - 2000 ft
(0 - 610 m)
3.5 - 32 ft
7
No
modification required
No
modification required
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
33 - 57 ft
8
2000 - 4500 ft
(610 - 1372 m)
3.5 - 32 ft
8*
54*
47*
33 - 57 ft
8*
55*
48*
4500 - 8000 ft
(1372 - 2439 m)
3.5 - 32 ft
9*
55*
48*
33 - 57 ft
9*
55*
49*
* Above 2000 ft, CO
2
levels must be checked with a combustion gas analyzer, see section
6.4
for instructions.
Table 20
Fan speed adjustment for 3" piping
Natural Gas
Liquid propane
Altitude
(above sea
level)
Total
equivalent
vent length
1)
1)
Full equivalent length (inlet + outlet fittings)
Minimum
power fan
speed (P2)
Maximum
power fan speed
(P1)
Maximum
power fan speed
(P1)
0 - 2000 ft
(0 - 610 m)
2.25 - 59 ft
7
No
modification required
No
modification required
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
60 - 122.5 ft
8
2000 - 4500 ft
(610 - 1372 m)
2.25 - 59 ft
8*
54*
47*
60 - 122.5 ft
8*
55*
48*
4500 - 8000 ft
(1372 - 2439 m)
2.25 - 59 ft
9*
55*
48*
60 - 122.5 ft
9*
55*
49*
* Above 2000 ft, CO
2
levels must be checked with a combustion gas analyzer, see section
6.4
for instructions.
Table 21
Fan speed adjustment for 4" piping
