2 Rinnai Circ-Logic™ with Grundfos Kit
Rinnai Water Heaters that Incorporate Circ-Logic™
The table below indicates the beginning serial number for each model that has the Circ-Logic™ feature.
Model Serial Number Part Number
RL75i (VC) REU-VC2528FFUD-US(A) Units with an "(A)" on the end of the part
number.
RL75e (VC) REU-VC2528WD-US(A)
RL94i (VC) DB.CA-016788 and higher REU-VC2837FFUD-US
RL94e (VC) DC.BA-013335 and higher REU-VC2837WD-US
RU98i DB.BA-006175 and higher REU-KB3237FFUD-US
RU98e DB.BA-006213 and higher REU-KB3237WD-US
RU80i DB.BA-006201 and higher REU-KB2530FFUD-US
RU80e DB.BA-006195 and higher REU-KB2530WD-US
Benets of Circ-Logic™:
Energy Eciency: Circ-Logic™ enables the homeowner to use the Economy Mode and thus cycle the
pump less oen, using less energy to maintain loop temperature.
Greater Comfort: If desired, the Comfort Mode can be used to re-heat the circulaon loop more fre-
quently and thus ensure the temperature remains high, even in high-heat loss loops.
Improved Durability: By reducing overall cycle frequency, Circ-Logic™ helps to limit wear on the internal
workings of the tankless unit. With the Grundfos GTK15 kit, wear and tear is further
minimized because the system is only acve when you want it to be.
Table of Contents
Benets of Circ-Logic™ ...................................... 2
Rinnai Water Heaters that
Incorporate Circ-Logic™ ..................................... 2
Kit Contents ....................................................... 3
Disclaimers ......................................................... 3
Rinnai Circ-Logic™ Descripon .......................... 4
Pipe Length ........................................................ 5
System Drawings ................................................ 5
Pump Installaon ............................................... 7
Wiring Pump to the Water Heater ..................... 8
Timer Technical Data ........................................ 10
Timer Technical Applicaon ............................. 10
Timer Operaon ............................................... 10
Troubleshoong ............................................... 11
Sequence of Operaon .................................... 11