Navien NPE-180A User Manual

Condensing Water Heater

Common Venting Guide

NPE-180(A,S)/ 210(A,S)/ 240(A,S)
Model :
When cascading the water heaters with other Navien water
heaters, you can install a common venting system. Do not use
common venting if the water heater is used in a cascading system
with other manufacturer's water heaters. Include a condensate
drain in the main trunk as illustrated in the following examples.
DANGER
Improper DIP switch settings can cause severe personal
injury, death or substantial property damage.
ON
1 2 3 4 5 6 7 8 9
Switch Function Setting
Common Vent
1 Cascade Vent
Individual Vent
The following are examples of common venting options:

Venting the Exhaust Only (Non-Direct)

●
H
W
Cap
Intake
ON
10 1 2
1-OFF
1-ON
Exhaust
D
Condensate
Drain
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Venting Intake and Exhaust to the Same Location

●
36" (900mm) min.
Intake
12" (300mm) min.
Cap
Venting Intake and Exhaust to Di erent Locations
●
Cap

To determine the size of a common vent:

1. Add the BTU/H input ratings for each water heater in the
cascading system to determine the total BTU/H rating.
2. Determine the total length (L) of the common vent, which
consists of the horizontal width (W) and the vertical height
(H): Total length (L) = W + H.
H
W
Intake
Exhaust
12" (300mm) min.
Condensate
Drain
Exhaust
Intake
Condensate
Drain
Exhaust
D
Condensate
Drain