ATI-540P Installation Manual

26 Page
-Common-venng system-
The Indoor model can be vented together using the same exhaust and intake venting.
 Up to 8 water heaters can be common-vented together.
 A non-return valve (100113130) must be used for each water heater that is part of the system.
 The water heaters must all be direct-vented.
 The common-venting system shall be in accordance with the National Fuel Gas Code,
ANSI Z223.1/NFPA 54 and/or B149.1, Natural Gas and Propane Installation Code
(Current Editions), local codes, and the following manufacturer’s instructions.
 For common-venting pieces and components, the manufacturer recommends
Centrotherm's vent line.

Only the above allowable models can be common-vented together.
Different models cannot be common-vented.
CAUTION
Allowable models for common-venting
240 Indoor, 340 Indoor, 540 Indoor, 540P Indoor
Installaon
Installaon Manual
Intake
wall
Exhaust
Roof
Condensate drain port
Non-Return Valve
Exhaust
wall
Roof
Intake
Non-Return Valve
Condensate drain port
Exhaust
Intake
wall
Roof
Non-Return Valve
Condensate drain port
NOTICE
For details on the installation of a common-vent system, please refer to "Common
Venting Tankless Gas Water Heaters." It is a manual which is available on the water
heater manufacturer's website.