Installation Sheet

Rinnai Tankless Water Heater Installaon and Operaon Manual 39
For the table below:
• Header is the main vent pipe into which several vents connect.
• Vent Length is the distance from the end of the header to the
vent terminaon.
• Maximum vent length starts at the end of the header system.
• Use 10  (3 m) as equivalent vent length for 90° elbows.
• For use with CU160i and CU199i internal (indoor) tankless
water heaters only.
Header
Vent Length
Common Vent Maximum Equivalent Vent Lengths
Common Vent Maximum Equivalent Vent Length
Rinnai Common Vent System or Schedule 40 PVC/CPVC
Water Heater
Model
# Water
Heaters
Max System
BTU/HR
HEADER DIAMETER
3 in. 4 in. 6 in.
3 in.
Vent Diameter
4 in.
Vent Diameter
6 in.
Vent Diameter
6 in.
Vent Diameter
CU199i
(REU-N3237FFC-US)
2 398,000 65 FT
150 FT
150 FT
150 FT
3 597,000
4 796,000 65 FT
5 995,000
6 1,194,000
7 1,393,000 70 FT
8 1,592,000
CU160i
(REU-N2530FFC-US)
2 320,000 90 FT 150 FT
150 FT 150 FT 3 480,000 100 FT
4 640,000 65 FT