Venting & Accessories

Rinnai's venting systems are the most flexible in the industry, fully CSA-certified, and use polypropylene PP — a more robust venting material for the job and able to withstand temperatures up to 230ºF. Our additional accessories ensure every business can customize their system for their needs.

Easy Installation

Vent lengths up to 100’ with seven TWH units; 41’ with 12 TWH units using 6" diameter venting. There are easy push fit joints—no cement or glue required.

Venting Benefits

The integrated check valve prevents backflow of exhaust gases into idle tankless water heaters. Common venting also reduces wall and ceiling penetrations.

Flexible Options

There are more options for indoor installations. Installations can also be in-line or back-to-back with a horizontal or vertical termination.

Common Venting

Room Air

Multiple unit installations use the air in the room for intake air, requiring only one vent penetration for the exhaust, saving time during installation. Room air can be used only in applications that utilize the approved Rinnai common vent method.

Direct Vent

Direct venting can be done in different plane configurations with a vertical exhaust vent and side wall intake for the U.S. and Canada. Both the direct vent and room air solutions use Rinnai’s existing 3", 4" or 6" venting material and are approved for markets that require ULC S636 for venting.


Single-Unit Vent

The dual venting configurations on the top of the unit allow for maximum flexibility for installers and dealers — one concentric vent or two PVC/CPVC pipes can be used for venting.

HE+ Series tankless water heaters must use concentric venting with a metal exhaust pipe. Refer to the Installation and Operation Manual supplied with the HE+ Tankless Water Heater for venting options.

Vent Options for CU Series

Vent Options
Vent Material
Exhaust Intake
Diameter
Header Vent
Max Units Maximum Vent
Length
Concentric Pipe
Polypropylene Schedule 40 PVC
5 in
4 in
1
150 ft
65 ft
Twin Pipe
Polypropylene* or
Schedule 40
PVC/CPVC
Schedule 40
PVC/CPVC
3 in
2 in
1
150 ft
65 ft
Common Vent
Polypropylene* or
Schedule 40
PVC/CPVC
Polypropylene* or
Schedule 40
PVC/CPVC
3 in
4 in
4 in
6 in
6 in
3 in
4 in
6 in
6 in
6 in
2
4
7
8
12
65 ft
2-3 Units: 150 ft

4 Units: 70 ft
5-6 Units: 150 ft

7 Units: 70 ft
2-3 Units: 150ft
9-10 Units: 90 ft

11-12 Units: 41 ft

*Twin Pipe Polypropylene venting is provided by Centrotherm through their own
distribution network.

Additional Accessories

Get a custom solution and a professional installation for your business from our Rinnai experts.

Compatible Tankless Models

CU199

CU199

Condensing

The highest standards of efficiency producing an endless supply of hot water.

View Models
CU160

CU160

Condensing

Offering 97% Thermal Efficiency with a heat exchanger built for commercial demands.

View Models