Specifications

VENT TYPE
NATURAL GAS
UNITS
MAXIMUM
EQUIVALENT
VENT LENGTH
PROPANE UNITS
MAXIMUM
EQUIVALENT
VENT LENGTH
3" PVC/CPVC
65 Feet*
41 Feet
4" PVC/CPVC
100 Feet*
65 Feet
* Maximum equivalent vent lengths are specific to the fuel type of the
tankless water heater. Use of elbows in installation will reduce the
maximum vent length. It is imperative when performing equivalent vent
length calculations, that you refer to the Installation Manual and any
applicable technical bulletins.
VENT TYPE
NATURAL GAS
UNITS
MAXIMUM
EQUIVALENT
VENT LENGTH
PROPANE UNITS
MAXIMUM
EQUIVALENT
VENT LENGTH
Concentric PP
65 Feet*
41 Feet
Twin Pipe PP
(Centrotherm)
41 Feet*
41 Feet
* Maximum equivalent vent lengths are specific to the fuel type of the
tankless water heater. Use of elbows in installation will reduce the
maximum vent length. It is imperative when performing equivalent vent
length calculations, that you refer to the Installation Manual and any
applicable technical bulletins.
The new RUC98i, RUC90i and RUC80i models of the Rinnai Ultra Series Tankless Water Heaters are the only tankless water
heaters to offer Concentric Polypropylene or PVC/CPVC venting options on the same unit. The dual venting configuration on the
top of the new RUC Tankless Water Heaters allows for maximum flexibility for installers and dealers — one Concentric vent or
two PVC/CPVC pipes can be used for venting.
As the #1 selling brand of tankless water heaters in the U.S. and Canada, we still favor Concentric Polypropylene for its superior
joint fit, no cure time, quick installation and reduced wall or roof penetrations, but as leaders in the industry, we understand that
PVC/CPVC can sometimes be more readily available or preferred in some installations.
Rinnai is the only tankless water heater manufacturer to offer both Concentric and PVC/CPVC on the same unit, providing more
venting options right out of the box — saving time, money and offering the best flexibility for faster installations in homes and
businesses — from one project to the next.
Some of the dual pipe venting options that are now available with the RUC Tankless Water Heaters include:
• 3" or 4" PVC/CPVC*
• 3" Centrotherm InnoFlue Vent System (ULC-S636 listed)*
For PVC/CPVC configurations, the intake cap is removed and discarded.
With this option, installers can use three- or four-inch PVC/CPVC pipe for
the intake and exhaust.
Intake Cap
For concentric venting, installers simply remove
and discard the exhaust adapter ring.
Exhaust
Adaptor Ring
A First in Both Concentric and PVC/CPVC Venting for Condensing
Tankless Water Heaters On One Unit
*Reference Rinnai Tankless Water Heater Installation and Operation Manual for further information.
• Snorkel and Tee Terminations*
• IPEX Concentric and Low Prole Termination Kit*
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FLEXIBLE TANKLESS VENTING OPTIONS