Rinnai REU-V2520FFU Operation & Installation Manual page 36

I N S TA L L E R ' S I N S TA L L AT I O N I N S T R U C T I O N S
Air Intake and Exhaust Vent Pipe Length
Determine the number of elbows in the vent system. The corresponding number from the table
indicates the maximum length of vent pipe.
For high altitude installations contact Rinnai at 1-800-621-9419.
0
41 (1)
Two 45 elbows are considered equivalent to one 90° elbow.
Include termination elbows when using this table.
(1) If the length is less than 22' then move dip switch no. 1 (SW 1) to ON
(2) If the length is less than 16' then move dip switch no. 1 (SW 1) to ON
(3) If the length is less than 10' then move dip switch no. 1 (SW 1) to ON
If it is necessary to adjust the dip switch, ensure that no other dip switches are
changed. Unauthorized adjustments can cause property damage, personal
injury, scalding, or death.
Intake/Exhaust Guidelines
• This water heater is a direct vent water heater and therefore is certified and listed with the
vent system. The only vent/air intake system listed for use with this appliance is the Rinnai /
Ubbink vent system or the Heat-Fab Saf-T Vent SC system.
• Minimum wall thickness is 4". Maximum wall thickness is 20".
• Do not combine vent components from different manufacturers.
• The vent system must vent directly to the outside of the building and use outside air for
combustion.
• 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.
• The first vent component to the appliance must be an appliance adapter. This will prevent
additional components from being installed backwards.
Rinnai America
Venting
Table 1 Maximum Vent Length (feet)
Number of 90° Elbows
1 2
35 (2) 29 (3)
3 4
23 17

5 6
11 5
FF Models