Installation Sheet
Rinnai Tankless Water Heater Installaon and Operaon Manual 19
Three types of venng opons are available:
Concentric Pipe
Combuson air and exhaust vent directly through a
single concentric connecon. Hot exhaust exits
through the interior tube, while combuson air enters
through the outer layer.
Exhaust
Exhaust
Combuson
air
Combuson
air
Combuson
air
Combuson
air
Exhaust
Direct Vent
Non-Direct (Room Air) Vent
Mulple water heaters sharing a combuson air header
and a separate exhaust header that vents directly through
separate penetraons to the outside.
Combuson Air
Exhaust
Exhaust
Room Air
For Combuson
Twin Pipe
Combuson air and exhaust vent directly through
separate penetraons.
Room Air
Room air is used for combuson while exhaust
vents to the outside.
External (Outdoor)
External (outdoor) water heater.
Exhaust
Combuson
air
Mulple water heaters using room air for combuson
while sharing an exhaust header that vents directly to
the outside.
Select a Vent Type
Direct Vent (Concentric Pipe and Twin Pipe)
1
Non-Direct Vent (Room Air and External)
2
Common Vent (Indoor Units Only. Direct Vent and Non-Direct/Room Air Vent)
3