Rinnai Circ-Logic RU98i User Manual

100000284 Rev D 1 Rinnai Circ-Logic™ with Grundfos Kit
Descripon
Rinnai Circ-Logic™ oers homeowners
enhanced convenience and energy
eciency in home hot water recirculaon
systems with a dedicated return line. Circ-
Logic™ controls the on/o sequence and
operaonal cycles of the recirculaon pump
through the programming of the tankless
water heater's control board. This feature is
standard on Rinnai's Ultra and Luxury Series
units.
Circ-Logic™ has been designed to provide
homeowners with the ability to customize
their recirculaon systems based on such
key variables as length of recirculaon loop,
piping insulaon, and the homeowner's
comfort and eciency preferences.
The GTK15 kit, manufactured by Grundfos,
allows the user to enjoy further energy
savings through the use of a mer.
For specic informaon on warranty with
circulaon, please visit
hp://www.rinnai.us/warranty
Rinnai Circ-Logic™
With Grundfos GTK15 Kit

Rinnai Circ-Logic RU98i Specifications

General

Category	Tankless Water Heater
Model	RU98i
Gas Type	Natural Gas or Propane
Energy Factor	0.95
Maximum Flow Rate	9.8 GPM
Minimum Flow Rate	0.26 GPM
Activation Flow Rate	0.4 GPM
Circ-Logic	Yes
Heat Exchanger	Stainless Steel
Maximum BTU Input	199, 000 BTU
Minimum BTU Input	15, 000 BTU/h
Temperature Range	98°F - 185°F
Vent Length	Up to 65 feet
Electrical Requirements	120V AC
Ignition System	Electronic
Warranty	12-year on heat exchanger, 5-year on parts, 1-year on labor

Summary

Rinnai Circ-Logic™ Overview

Product Description

Provides an overview of Rinnai Circ-Logic™, highlighting its convenience, energy efficiency, and control over hot water recirculation pumps.

Circ-Logic™ System Details

Benefits of Circ-Logic™

Details the advantages of Circ-Logic™ including energy efficiency, greater comfort, and improved durability for homeowners.

Compatible Rinnai Water Heaters

Lists Rinnai water heater models that incorporate the Circ-Logic™ feature, including their serial number ranges.

Kit Contents and Disclaimers

GTK15 Kit Contents

Lists the components included in the GTK15 Kit, such as the Grundfos pump, electrical cord, and manual.

Installation Disclaimers

Outlines important disclaimers regarding installation, professional engineering, and compliance with local building codes.

Rinnai Circ-Logic™ Operation

Economy Mode Operation

Details how Economy Mode operates, focusing on longer time intervals for reduced energy consumption and pump cycles.

Comfort Mode Operation

Explains Comfort Mode's shorter time intervals for maintaining higher temperatures, suitable for high-heat loss loops.

Installation and Wiring

Pump Installation Requirements

Details required installer skills, pump specifications for indoor use, terminal box positioning, and pump orientation for correct flow direction.

Wiring Procedure and Dip Switch Settings

Provides step-by-step wiring instructions and details how to set the DIP switches for Economy or Comfort mode operation.

Timer Control and Operation

Timer Specifications and Operation

Details timer supply voltage, temperature range, switching intervals, application, and step-by-step operation for setting ON/OFF times.

Troubleshooting and Sequence

Pump Shaft Troubleshooting

Explains initial slow shaft rotation and provides steps for manually rotating the shaft if the pump does not run.

Circ-Logic and Timer Control Logic

Details the pump control logic based on the timer manual switch position (ON, TIMER, OFF) and Circ-Logic™ output.