Replaces model C199en.
With an enhanced combustion design, the Rinnai SENSEI Tankless Water Heater provides a better experience for both users and installers. Like all Rinnai Tankless Water Heaters, it's also vertically integrated. That means all key components are manufactured by Rinnai — to ensure Rinnai quality.
Condensing Technology for Colder Climates
The Rinnai SENSEI offers freeze protection down to -4o F (for outdoor units) or -22o F (for indoor units) through:
- NEW integrated check valve that prevents backflow from outside cold air
- NEW Fiber Mesh Premix Burner
- Integrated logic to temporarily activate the unit in extreme cold climates
Most Flexible Venting in the Industry
The Rinnai® Sensei™ can go in an old condensing vent system for replacement if needed, but new installs can use smaller, lighter, less expensive concentric venting.
Now Including 2" Venting Options
| Concentric |
| Diameter |
Equivalent Length |
Termination |
| 3" x 5" |
150' (46m) |
Vertical or Horizontal |
| 2" x 4" (New) |
65' |
Vertical or Horizontal |
- Unit requires only a single penetration through the wall, reducing install time and costs
- Simple positive-fit components offer a secure connection
- Joint seals expand and contract with weather to prevent damage
- Assembly and adjustment are easy
| Twin Pipe and Room Air |
| Diameter |
Material |
Equivalent Length |
Termination |
| 3" |
PP,PVC,CPVC |
150' (46m) |
Vertical or Horizontal |
| 2"(New) |
PP,PVC,CPVC |
65' |
Vertical or Horizontal |
Specifications
| Dimensions |
Product Width (inches): 14.76 |
| Product Height (inches): 33.86 |
| Product Depth (inches): 22.05 |
| Mobile Home Certified |
No |
| Product Weight (lbs) |
72.3 |
| Wi-Fi Capable |
Yes |
| Energy Star Certified |
Yes |
| Circ-Logic Compatible (S/N - Production Date) |
Yes |
| Recirculation Capable |
Yes |
| Recirculation Pump |
No |
| Cold Water Inlet Connection |
3/4" MNPT/19mm |
| Domestic Hot Water Temperature Range (Standard) (°F/°C) |
98F-120F 37C-49C |
| Domestic Hot Water Temperature Range (Optional) (°F/°C) |
98F-185F 37C-85C |
| Gas Supply Connection |
3/4" MNPT 19mm |
| Gas Type |
Propane |
| Hot Water Outlet Connection |
3/4" MNPT 19mm |
| Isolation Valves Included |
Yes |
| Manufacturer Model Number |
REU-N3237WC-US-P |
| Maximum BTU |
199,000 BTU/h |
| Minimum BTU |
15,000 BTU |
| Maximum Altitude |
10,200' |
| NOx Level |
150 PSI 1035 KPa |
| Commercial Warranty (Years) |
Heat Exchanger: 8, Labor: 1, Parts: 5 |
| Residential Warranty (Years) |
Heat Exchanger: 15, Labor: 1, Parts: 5 |
* It is recommended that a trained and qualified professional who has attended a Rinnai training class complete the installation. The warranty may be voided due to any improper installation.
— Installation and service must be performed by a licensed professional.
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Mobile Home Certified No
Product Weight (lbs) 72.3
Wi-Fi Capable Yes
Energy Star Certified Yes
Circ-Logic Compatible (S/N - Production Date) Yes
Recirculation Capable Yes
Recirculation Pump No
Cold Water Inlet Connection 3/4" MNPT/19mm
Domestic Hot Water Temperature Range (Standard) (°F/°C) 98F-120F 37C-49C
Domestic Hot Water Temperature Range (Optional) (°F/°C) 98F-185F 37C-85C
Gas Supply Connection 3/4" MNPT 19mm
Gas Type Propane
Hot Water Outlet Connection 3/4" MNPT 19mm
Isolation Valves Included Yes
Manufacturer Model Number REU-N3237WC-US-P
Maximum BTU 199,000 BTU/h
Minimum BTU 15,000 BTU
Maximum Altitude 10,200'
NOx Level 150 PSI 1035 KPa
Commercial Warranty (Years) Heat Exchanger: 8, Labor: 1, Parts: 5
Residential Warranty (Years) Heat Exchanger: 15, Labor: 1, Parts: 5
Product Height
31.3 in / (795 mm)
Product Width
18.5 in / (470 mm)
Product Depth
11.45 in / (290 mm)
Product Weight
64 lb / (29 kg)
Shipping Depth (inches/mm)
33.1 in / (841 mm)
Shipping Height (inches/mm)
33.1 in / (841 mm)
Shipping Width (inches/mm)
21.7 in / (551 mm)
Shipping Weight (lbs/kg)
73 lb / (33 kg)
