Installation Guide

38 Rinnai Tankless Water Heater Installation and Operation Manual
Twin Pipe Installation Instructions
The water heater is equipped with a 2 in. (51
mm) pipe connection. With the use of a pipe
reducer, installers can use a 3 in. (76 mm) pipe
for the Intake air and exhaust. In this case, a 2
in./3 in. pipe reducer should be installed as
close as possible to the water heater.
1. Remove and discard the screw from
the intake air vent connection.
2. Remove and discard the intake air vent
cap.
Supplied screws
4. Install the exhaust vent pipe. Ensure it is
properly seated.
Secure the exhaust vent pipe to the
exhaust adapter ring with the supplied
screws.
3. Install the intake air vent pipe. Ensure it is
properly seated.
Secure the intake air vent pipe to the intake
air vent connection with the supplied
screws.
DO NOT apply PVC glues, solvents, or
cleaners to the water heater’s intake air or
exhaust gasket connections. Failure to
correctly assemble the components
according to these instructions may result
in property damage, personal injury, or
death.
WARNING
Figure 26
Figure 27
Figure 28
Figure 29
1. Direct Vent (Twin Pipe )
Intake Air Vent Pipe
Exhaust
Supplied screws