Installation instructions
3.3.6Fan 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. Use this value to determine the appropriate fan speed values, found in Table 12 and make any necessary adjustments. After changing fan speed values proceed to Section 6.4 to confirm CO2 values are within specified ranges.
Total equivalent vent length calculation
BDetermine the total length of all straight sections of vent pipe and enter in table 10, line 1.
BCount the number of 90° elbows used and enter that value in line 2. (Do not count terminals and first elbow used on intake and exhaust).
BCount the number of 45° elbows used and enter that value in line 3.
BRepeat steps 1 through 3 for air intake pipe and enter those values in the intake section of table 10.
BAdd line 4 from Exhaust to line 4 of Intake and enter result in line 5.
This is the total equivalent vent length.
Exhaust
1 | Straight section length | __ x 1 = | ____ | |
| (feet) |
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2 | 90° elbows (qty) | __ x 2.5 = | ____ | |
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3 | 45° elbows (qty) | __ x 1.25 = | ____ | |
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4 |
| Total: | ____ | |
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Intake |
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1 | Straight section length | __ x 1 | = | ____ |
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2 | 90° elbows (qty) | __ x 2.5 | = | ____ |
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3 | 45° elbows (qty) | __ x 1.25 | = | ____ |
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4 |
| Total: | ____ | |
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5 | Total equivalent vent length = | ____ | ||
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Table 10 Determining vent length combination (see example in Table 11)
Example
Exhaust
•7 - 3' straight sections
•1 - 1' straight section = Total straight pipe length 22’
•2 - 90° elbow.
Intake
•5 - 3' straight sections = Total straight pipe length 15’
•1 - 90° elbows.
Example |
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Exhaust |
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Straight section length |
| 22 x 1 = | 22 |
(feet) |
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90° elbows (qty) |
| 1 x 2.5 = | 2.5 |
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45° elbows (qty) |
| 0 x 1.25 = | 0 |
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Total: |
| 24.5 | |
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Intake |
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Straight section length |
| 15 x 1 = | 15 |
(feet) |
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90° elbows (qty) |
| 1 x 2.5 = | 0 |
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45° elbows (qty) |
| 0 x 1.25 = | 0 |
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Total: |
| 15 | |
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Total equivalent vent length = |
| 39.5 | |
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Table 11 Determining vent length combination exam- ple
Note: Do not count terminals and first elbow used on intake and exhaust.
Total equivalent length must not to
iexceed 57ft.
NOTE: If using concentric terminal include
iexhaust pipe length that is part of the con- centric terminal.
6 720 608 542 | 17 |
