Reznor UEZ User Manual

Revision: UEZ-IOM (07-23) 1034347-I
GAS-FIRED UNIT HEATER INSTALLATION, OPERATION,
AND MAINTENANCE
Supersedes: UEZ-IOM (05-23) 1034347-H
MODEL UEZ
⚠ DANGER ⚠
FIRE OR EXPLOSION HAZARD
• Failure to follow safety warnings exactly could result in serious injury, death, or property
damage.
• Improper installation, adjustment, alteration, service, or maintenance can cause serious injury,
death, or property damage.
• Installation and service must be performed by a qualified installer, service agency, or the
gas supplier.
• Be sure to read and understand the installation, operation, and service instructions in this
manual.
• Do not store or use gasoline or other flammable 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.
• Leave the building immediately.
• Immediately call your gas supplier from a phone remote from the building. Follow the gas
supplier’s instructions.
• If you cannot reach your gas supplier, call the fire department.
DO NOT DESTROY. PLEASE READ CAREFULLY. KEEP IN A SAFE PLACE FOR FUTURE REFERENCE.

Reznor UEZ Specifications

General

Brand	Reznor
Model	UEZ
Category	Gas Heater
Language	English

Summary

General Information

Important Safety Information

Safety warnings and definitions provided in the manual.

References and Approvals

Related manuals, product certifications, warranty, and installation codes.

Heater Location and Airflow

Guidelines for unit placement, throw patterns, and mounting height.

Unit Specifications and Hazards

Weights, dimensions, condensate requirements, and chlorine hazards.

Venting and Combustion Air Requirements

Vent/Combustion Air Piping

Specifications for vent and combustion air piping systems.

Piping Joints and Support

Methods for joining and supporting vent and air pipes.

Installation

Pre-Installation and Suspension

Unpacking, checklists, and methods for mounting the heater.

Piping and Vent Connections

Connecting gas supply, vent system, and terminals.

Vent Terminal Installation

Steps for installing vertical and horizontal vent terminals.

Drain and Electrical Setup

Installing condensate drains and making electrical connections.

Controls

Key Control Components

Thermostat, gas valve, pressure switch, and limit controls.

Ignition and Venter Motor Controls

Circuit board, venter motor, and flame rollout switch.

Operation

Startup and Pre-Operation Checks

Checklists and procedures for starting the heater.

Operating Sequences and Testing

Normal/abnormal cycles and vent system testing procedures.

Adjustments

Pressure Switch and Gas Pressure

Replacing pressure switch and adjusting gas pressure for elevation.

Propane Conversion

Steps for converting the unit for propane fuel.

Maintenance

Routine Service and Procedures

Annual inspection, burner, heat exchanger, and ignition system maintenance.

Motor, Valve, and Switch Maintenance

Servicing fan motor, venter motor, gas valve, and limit controls.

Vent System and Drain Checks

Inspecting vent system and condensate drain for proper function.

Troubleshooting

General Troubleshooting Guide

A guide to diagnosing common unit problems and their causes.

DSI Control Module Diagnostics

Using the DSI control module display codes for diagnostics.