Rinnai Tankless Water Heater Installation and Operation Manual
49
3. Common Vent
(Indoor Units Only. Direct Vent and Non-Direct/Room Air Vent)
Common venting allows multiple Rinnai Tankless Water
Heaters to share the same vent system. When operating
multiple water heaters in a common venting system, it
is recommended to use Rinnai’s EZConnect™ cable
(purchased separately) which electronically connects two
water heaters so they function as one hot water source.
Do not common vent this water heater with any other water
heater or appliance.
Note: Multiple RSC models (water heaters with a
recirculation pump) cannot be electronically connected
using the EZConnect™ cable. The EZConnect™ cable
connects only an RSC model with an RU model. See
illustration below.
Vent Length
Figure 49: Sample Inline, Freestanding
Configuration
Water Heater Model
# Water
Heaters
Max System Btu/hr
Vent Diameter
3 in.
4 in.
6 in.
RSC199i: REU-NP3237FF-US(A)
and RU199i: REU-N3237FF-US
2
398,000
65 ft
(20 m)
150 ft
(46 m)
150 ft
(46 m)
RSC160i: REU-NP2530FF-US(A)
and RU160i: REU-N2530FF-US
2
320,000
90 ft
(27 m)
150 ft
(46 m)
150 ft
(46 m)
Table 22: Common Vent Maximum Vent Length
Header
Common Vent Maximum Equivalent Vent Lengths
Common vent equivalent lengths include polypropylene
pipe (PP) or PVC in a back-to-back or inline
configuration.
For the table below:
•
Header is the main vent pipe into which sev
-
eral vents connect.
•
Vent Length is the distance from the end of
the header to the vent termination.
•
Maximum vent length starts at the end
of the header system.
RSC199
(With Pump)
Primary
RU199
(Without Pump)
Secondary
RSC199
(With Pump)
RSC199
(With Pump)
CORRECT
NOT CORRECT
Figure 50
Figure 51
Figure 52
