Installation Manual
Rinnai Tankless Rack System (TRS) Installation Manual     41 
Each Rinnai Tankless Water Heater has a condensate 
drain outlet on the boom of the unit. A drain line 
must be connected to each water heater. 
Free-standing rack systems with 3 or more units will 
include a prefabricated condensate manifold. For all 
other rack systems, a condensate drain manifold must 
be eld-fabricated (not shown in diagram). 
Condensate piping must be CPVC or PVC material and 
must not be smaller than the drain connecon on the 
appliance. 
Components of the condensate drainage shall be 
CPVC or PVC material. All components must be 
selected for the pressure and temperature rang of 
the installaon. 
Where the drain pipes from more than one unit are 
manifolded together for condensate drainage, the 
pipe or tubing shall be sized in accordance with an 
approved method as dictated by local codes. 
Condensate must be disposed of according to local 
codes. 
The condensate drain pipe (along its enre 
length) must be at least the same diameter as the 
drain line. 
TRS03ILCU TRS03CU TRS04CU 
TRS36CU TRS46CU TRS05CU 
 TRS06CU 
Condensate manifolds are installed above the water 
manifolds of the following racks for single point 
condensate connecon. Models available with 
condensate manifolds include: 
Condensate drain must be sloped downward from the rack 
system. Condensate must be disposed of per local codes. 
Field-supplied  
PVC 
Condensate Manifold 
3/4” Connecon 
The telescoping ng on the 
capped side of the conden-
sate manifold is for air relief. 
DO NOT plug the opening. 
 NOTICE 
Piping Diagram for  
Basic Installaon 
Condensate Manifold 
Condensate Drain 
Condensate 
Trap Drain 
Plug 
Pressure Relief Valve  
Connecon 
Cold Water 
 Inlet 
Condensate  
Drain Line 
Hot Water  
Outlet 
Gas  
Connecon 










