Rinnai RUCS75i series User Manual

Direct Vent Tankless Water Heater
Installaon and Operaon Manual
 

 
 
 
 
 
 


WARNING

This manual provides informaon on the installaon, operaon, and maintenance of the water heater. For proper
operaon and , it is important to follow the instrucons and adhere to the safety precauons.
A licensed professional must install the water heater according to the exact instrucons in this manual.
The consumer must read the enre manual to properly operate the water heater and to have regular maintenance
performed.

FOR INDOOR APPLICATIONS ONLY
RUCS65i ................ --
RUCS75i ................ --
FOR OUTDOOR APPLICATIONS ONLY
RUS65e ................. --
RUS75e ................. --



C US
U328-0700

Rinnai RUCS75i series Specifications

General

Category	Water Heater
Series	RUCS75i
Type	Tankless
Fuel Type	Natural Gas
Flow Rate	7.5 GPM
Energy Factor (EF)	0.82
Gas Connection	3/4" NPT
Water Connection	3/4" NPT
Location	Indoor
Minimum BTU Input	15, 000 BTU/hr
Activation Flow Rate	0.4 GPM
Thermal Efficiency	0.95
Temperature Range	98°F - 140°F
Electrical Requirements	120V, 60Hz
Venting	Direct Vent
Ignition Type	Electronic Ignition
Warranty	12 years heat exchanger, 5 years parts, 1 year labor

Summary

Direct Vent Tankless Water Heater Installation and Operation Manual

Important Safety Warning

Crucial safety warning regarding fire or explosion if instructions are not followed exactly.

Important Safety Information

Safety Definitions

Defines DANGER, WARNING, and CAUTION symbols used to indicate potential hazards.

Safety Behaviors and Practices

Consumer and Installer Precautions

Guidelines for safe operation, maintenance, and handling of the water heater.

Installation Instructions

Installer Qualifications

Skills required for a licensed professional to install the appliance.

General Installation Instructions

Key DO NOT and MUST DO requirements for proper installation.

Direct Vent Terminal Clearances (Indoor Units)

Other Than Direct Vent Terminal Clearances (Outdoor Units)

Unit Clearances

Freeze Protection

Measures to protect the water heater and lines from freezing damage.

Installation of Venting (indoor models only)

Approved Vent Manufacturers

List of manufacturers and their tested vent products for the appliance.

Venting Guidelines

Determining Vent Configuration

Setting DIP switches for concentric or twin pipe venting.

Maximum Vent Length

Maximum Vent Length with Concentric Venting

Maximum Vent Length with Twin Pipe PVC / CPVC

Twin Pipe PVC/CPVC Vent Installation

Installation of PVC/CPVC Vent and Intake Air Piping

Required Parts For 3” PVC/CPVC Assembly Configuration

Certified PVC/CPVC Vent Termination Options

Vent Termination Configurations

Certified PVC/CPVC Vent Termination Options (continued)

PVC/CPVC Equivalent Vent Length Calculation Sheet

Installation of Plumbing

Pressure Relief Valve Requirements

Connect Water Heater to Water Supply

Installation of Gas Supply

Installation of Optional Temperature Controller

Controller Location

Final Checklist

Technical Data

Specifications

Detailed technical specifications for different models.

Pressure Drop and Water Flow Curves

Operation Instructions

Important Facts about your Water Heater

Consumer Operation Guidelines

OPERATING INSTRUCTIONS

Step-by-step guide for safe operation of the water heater.

How to Set the Temperature

Temperature Options Without a Temperature Controller

How to use the Optional Temperature Controller

Diagnostic Codes

Diagnostic Information (on status monitor)

Diagnostic Codes and Remedies

Required Maintenance

Cleaning

Procedures for cleaning control compartments, burners, and air passageways.

Vent System Maintenance

Freeze Protection

Flushing the Heat Exchanger

Manual Draining of the Water Heater

Limited Warranty

What is covered?

What is not covered?