Installation Manual
46  Rinnai Tankless Rack System (TRS) Installation Manual
Configuring TRW02ST and 
TRW03ST Rack Models 
11 
This Secon is Applicable for TRW02ST and TRW03ST Rack Models Only 
TRW02ST and TRW03ST rack models are designed for the SE+ Featuring ThermaCirc360™ tankless water heaters, 
which include a built-in recirculaon pump and two recirculaon modes:  
CROSSOVER MODE 
(Factory Default)  Home/
business includes a 
dedicated circulaon return 
line in the plumbing 
system. All TRW02ST and 
TRW03ST rack models and 
the RUR199 Tankless Water 
Heater are shipped 
congured for a dedicated 
recirculaon return line.  
Home/business does not 
include a dedicated circulaon 
return line. Requires 
installaon of a thermal bypass 
valve (included with purchase) 
at the furthest xture in the 
plumbing system.  
DEDICATED MODE 
DO NOT install in combinaon with hydronic 
heang applicaons. 
DO NOT install the MC-195T-US Timer/Controller 
and Control-R™ Wi-Fi Module together as they 
are not compable accessories.  
•  For the licensed installer / professional 
•  For installaon in residenal domesc hot water  
applicaons only.  
•  Rinnai strongly recommends installing insulaon 
to the hot water and dedicated return lines to 
decrease the amount of heat loss. 
General Guidelines 
Water drain plug 
Condensate drain line 
Gas connecon 
Cold water inlet with lter 
Hot water outlet with 
bypass plug / lter  
Check valve drain plug 
Condensate trap 
drain plug 
PRV Connecon 
Thermal bypass  
valve  
See the following secon for Crossover Mode 
instrucons: Congure TRW02ST and TRW03ST Racks 
For Crossover Mode (Thermal Bypass Valve) 
See the following secon for Dedicated Mode in-
strucons: Congure TRW02ST and TRW03ST Racks 
For Dedicated Mode (Dedicated Recirculaon Return 
Line)  
Connection Diagram 










