Rinnai REU-V3237FFU Operation & Installation Manual page 32

Intake/Exhaust Guidelines
• This water heater is a direct vent water heater and therefore is certified and listed with the vent
system. Only use venting identified in these instructions for proper installation.
• Do not combine vent components from different manufacturers.
• Before installation, inspect each vent component for damage and correct seal placement. Do
not attempt to fix or install any damaged vent components.
• Every vent connection must be accessible for inspection, cleaning, and replacement.
• Avoid dips or sags in horizontal vent runs by installing supports per the vent manufacturers'
instructions.
• Support horizontal air intake runs every four feet and all vertical air intake runs every six feet
or in accordance with local codes.
• Venting should be as direct as possible with a minimum number of pipe fittings.
• Vent diameter must not be reduced.
• Do not connect the venting system with an existing vent or chimney.
• Do not common vent with the vent pipe of any other water heater or appliance.
• Vent connections must be firmly pressed together so that the gaskets form an air tight seal.
• Refer to the vent pipe manufacturers' instructions for component assembly instructions.
Air Intake Assembly
The combustion air for the Rinnai Tankless Water
Heater is supplied directly from the outdoors
through the air intake system. The air intake
system consists of a field supplied stainless steel,
4" Schedule 40 PVC, ABS, or CPVC pipe. A
maximum 6 feet of semi-rigid flexible aluminum
ducting can also be used. Foil wrapped dryer vent
and cell core products are not authorized.
Air Intake Connection
Refer to Figure 2
1. Predrill two small holes at the end of the air
intake pipe.
2. Slide the pipe over the air intake terminal.
3. Using a level, ensure the pipe is straight up
and down.
4. With self tapping screws, attach the pipe to the
air intake terminal.
5. Apply a bead of silicone around the pipe
and air intake terminal, ensuring an air tight
connection.
Exhaust Pipe Assembly
Category III vent pipe must be used throughout
the entire exhaust system.
Refer to Figures 3 for clearances to
combustibles and Figure 4 for approved parts.
Rinnai Corporation
FIGURE 2
1
3
FIGURE 3
32
2
4
V3237 Models