Rinnai . REU-VC2025FFU-US User Manual

Direct Vent Tankless Water Heater
Installaon and Operaon Manual
— Do not store or use gasoline or other ammable vapors and liquids in the vicinity of this or any other
appliance.
— WHAT TO DO IF YOU SMELL GAS
 Do not try to light any appliance.
 Do not touch any electrical switch; do not use any phone in your building.
 Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instrucons.
 If you cannot reach your gas supplier, call the re department.
— Installaon and service must be performed by a licensed professional.
This enre manual must be le for the consumer. The consumer must read and
refer to this manual for proper operaon and to maintain the water heater.
If the informaon in these instrucons is not followed exactly, a re or explosion
may result causing property damage, personal injury or death.
WARNING
READ ALL OF THE INSTRUCTIONS THOROUGHLY BEFORE INSTALLING OR OPERATING THIS WATER HEATER.
This manual provides informaon on the installaon, operaon, and maintenance of the water heater. For proper
operaon and safety, 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 on pages 4-27.
The consumer must read the enre manual to properly operate the water heater and to have regular maintenance
performed.
ANS Z21.10.3 ● CSA 4.3
FOR INDOOR APPLICATIONS ONLY
V94i ...................... REU-VC2837FFU-US
V94Xi .................... REU-VC2737FFU-US
V75i ...................... REU-VC2528FFU-US
V65i ...................... REU-VC2025FFU-US
FOR OUTDOOR APPLICATIONS ONLY
V94e ..................... REU-VC2837W-US
V75e ..................... REU-VC2528W-US
V65e ..................... REU-VC2025W-US
SANITATION
Low Lead Content
NSF/ANSI 372
C US

Rinnai . REU-VC2025FFU-US Specifications

General

Fuel Type	Natural Gas
Dimensions	14.2 x 24.1 x 29.5 inches
Weight	52 lbs
Gas Type	Natural Gas
Energy Factor	0.82
Venting	Direct Vent
Ignition System	Electronic Ignition
Heat Exchanger	Copper
Power Vent	Yes
Voltage	120V
Ignition Type	Electronic
Type	Tankless
Heating Capacity	199, 000 BTU/hr
Energy Efficiency	0.82
Minimum BTU Input	15, 000 BTU/h
Temperature Range	98°F - 140°F
Minimum BTU	15, 000 BTU/h
Warranty	12 years heat exchanger, 5 years parts

Summary

Safety Behaviors and Practices for the Consumer and Installer

General Safety Precautions

Essential safety rules for operating and maintaining the water heater, including gas detection.

Maintenance Safety

Steps to ensure personal safety before performing maintenance on the appliance.

Cautionary Notes

Installation Instructions (for the licensed professional)

Installer Qualifications

Skills required for professional installation, including gas sizing, connections, codes, and venting.

General Instructions

Determine Installation Location

Water Quality Considerations

Guidance on evaluating water quality to prevent heat exchanger damage.

Environmental Factors

Terminal Clearances

Clearance Requirements

Unit clearances

Clearances for Indoor Models

Clearances for Outdoor Models

Freeze Protection

Preventing Freezing Damage

Recommendations to protect the water heater and lines from freezing.

Condensate (indoor models only)

Condensate Drainage Requirements

Installation of Plumbing

Pressure Relief Valve Requirements

Requirements for installing an approved pressure relief valve according to codes.

Isolation Valves

Installation of Gas Supply

Gas Supply Installation Safety

Critical safety warnings and steps for professional gas supply installation.

Pipe Sizing Table - Natural Gas

Natural Gas Pipe Sizing Chart

Pipe Sizing Table - Propane Gas

Propane Gas Pipe Sizing Chart

Connect Electricity

Electrical Connection Safety

Guidelines for safe electrical connection, grounding, and power requirements.

Final Checklist

Pre-Operation Verification Checklist

Comprehensive checklist for ensuring all installation steps are complete and correct.

Specifications

Technical Data Summary

Ladder Diagram

Electrical Circuit Diagram

Operation Instructions

Gas Leak Safety

Critical steps to take if a gas leak is suspected.

Consumer Operation Guidelines for the Safe Operation of your Water Heater

Safety Before Operating

Critical safety warnings and gas leak procedures before initial operation.

Operating Instructions

Step-by-step guide for safely starting and operating the water heater.

Turning Off Gas to Appliance

Procedure for safely shutting off the gas supply to the appliance.

How to use the Temperature Controller

Controller Features and Operation

How to Set the Temperature

Temperature Setting Procedure

Steps for setting the desired water temperature using the controller.

Temperatures Available with a Controller

Available Temperature Settings

Diagnostic Codes

Displaying Diagnostic Information

Diagnostic Codes and Remedies

Code 10: Air Supply or Exhaust Blockage

Code 16: Over Temperature Warning

Code 11: No Ignition

Troubleshooting steps when the heater fails to ignite.

Code 12: No Flame

LC Codes: Scale Build-up

Guidance for dealing with scale build-up indicated by LC diagnostic codes.

Required Maintenance

Annual Inspection and Cleaning

Procedures for annual inspection and cleaning of the appliance components.

Lime/Scale Build-up and Water Quality

Addressing scale build-up and water quality impact on the heat exchanger.

Winterization Recommendations

Practices for winterizing the water heater, including gas, water, and electric steps.

Flushing the Heat Exchanger

Heat Exchanger Flushing Procedure

Step-by-step guide using vinegar to flush the heat exchanger.

Manual Draining of the Water Heater

Procedure for Manual Draining

Steps to manually drain the water heater for storage or freezing prevention.

State Regulations

Massachusetts Regulations

Consumer Warranty

Limited Warranty Coverage

Details on what the warranty covers and its duration for different components.

Warranty Exclusions

Lists items and conditions not covered by the warranty.

Rinnai's Responsibilities