Installation instructions
Condensate drain requirements
An external condensate drain (not supplied with the heater) must be installed under the following conditions:
•All vertical terminating vent installations.
•Horizontal terminating vent installations where the total linear vent length is greater than 10 feet (3.1 m).
•Vent installations where any section of the exhaust vent pipe passes through an unconditionedspace.
Twin pipe termination clearances
The minimum clearance between exhaust vent and combustion air inlet terminations for twin pipe penetration is 3 feet.
Minimum combustion air and exhaust pipe length
The minimum exhaust pipe length is 3 feet (1m) of straight vent pipe. The minimum combustion air pipe length is one 90° elbow.
Maximum combustion air and exhaust pipe length
The following table (Table 6) displays the maximum allowable straight pipe lengths for combustion air and exhaust piping with consideration to the number of elbows used.
Note: 90° elbows used for terminations
ishould not be counted in the exhaust and combustion air piping.
Step 1: Total the number of 90° elbows and 45° elbows used on the exhaust piping.
Step 2: Use this value in the table to determine the
maximum straight exhaust pipe length allowed.
Step 3: Total the number of 90° elbows and 45° elbows used on the combustion air piping.
Step 4: Use this value in the table to determine the maximum straight combustion air pipe length allowed.
Air intake or |
| # of 90° elbows |
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Exhaust |
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system |
| 0 | 1 | 2 | 3 | 4 | |
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| 0 | N/A* | 26 | 21 | 16 | 11 |
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| 1 | N/A* | 23 | 18 | 13 | 8 |
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| 2 | 23 | 20 | 15 | 10 | 5 |
# of 45° |
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| 3 | 20 | 17 | 12 | 7 | N/A** | |
elbows |
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| 4 | 17 | 14 | 9 | 4 | N/A** |
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| 5 | 14 | 11 | 6 | N/A** | N/A** |
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| 6 | 11 | 8 | 3 | N/A** | N/A** |
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Maximum allowable straight pipe length (ft)
Table 6 Maximum allowable straight pipe length
*Not allowed. At least one 90º elbow required.
**Not allowed. Minimum of 3 feet (1m) of straight pipe required.
6 720 608 542 | 11 |
