Rheem Furnace Repair Manual

The Rheem Furnace is a high-efficiency heating system designed for residential and commercial applications, featuring advanced combustion technology, variable-speed blower motors, diagnostic LED systems, and multiple safety controls. Below are key sections for safety procedures, technical specifications, troubleshooting, maintenance, and repair instructions.

1. Safety Precautions 2. System Overview 3. Technical Specifications 4. Installation Guidelines 5. Operation Controls 6. Diagnostic Procedures 7. Common Repairs 8. Maintenance Schedule 9. Error Code Reference 10. Parts Replacement 11. Troubleshooting Guide

Safety Precautions

Critical safety measures must be followed before performing any service or repair work on the furnace.

HazardPrecaution
Electrical ShockDisconnect power at main breaker before servicing
Gas LeaksCheck for leaks with soap solution; never use open flame
Carbon MonoxideEnsure proper ventilation; install CO detectors
Hot SurfacesAllow furnace to cool completely before servicing
Moving PartsDisconnect power before accessing blower assembly

System Overview

Key components: Burner assembly, heat exchanger, blower motor, gas valve, control board, igniter, flame sensor, pressure switches, and venting system.

  1. Burner Assembly: Stainless steel construction for durability
  2. Heat Exchanger: Primary and secondary heat transfer surfaces
  3. Blower Motor: Variable-speed ECM for efficiency
  4. Control Board: Microprocessor with diagnostic capabilities
  5. Safety Controls: Multiple pressure and temperature switches

WARNING! Only qualified technicians should perform repairs. Improper installation or repair can cause fire, explosion, or carbon monoxide poisoning.

Technical Specifications

Installation Guidelines

Proper installation ensures safe and efficient operation.

  1. Location: Install in well-ventilated area with adequate clearance
  2. Venting: Follow manufacturer specifications for vent pipe size and length
  3. Gas Connection: Use approved pipe compound on male threads only
  4. Electrical: Follow local codes; provide dedicated circuit
  5. Ductwork: Ensure proper sizing and sealing
  6. Combustion Air: Provide adequate fresh air supply

CAUTION! Installation must comply with all local building codes and manufacturer specifications.

Operation Controls

Understanding furnace controls and settings for proper operation.

Thermostat: Heat/Cool/Auto settings, fan control, temperature setpoints

Control Board: LED diagnostic lights, dip switch settings, reset button

Gas Valve: Manual shutoff, pressure regulator, solenoid operation

Blower Control: Speed taps, delay settings, continuous fan operation

Sequence of Operation: Thermostat call for heat → inducer motor starts → pressure switch proves draft → hot surface igniter glows → gas valve opens → flame sensor confirms ignition → blower starts after heat exchanger warms

Diagnostic Procedures

Systematic approach to identifying furnace problems.

  1. Check power supply: Verify 120V at furnace and 24V at transformer
  2. Review error codes: Interpret LED flash patterns
  3. Test safety controls: Pressure switches, rollout switches, limit switches
  4. Check gas supply: Verify gas pressure and valve operation
  5. Test ignition system: Hot surface igniter and flame sensor
  6. Inspect venting: Check for obstructions and proper draft

Tip: Always start diagnostics with the simplest possibilities first.

Common Repairs

Frequently performed repairs and replacement procedures.

  1. Flame Sensor Cleaning: Remove, clean with emery cloth, reinstall
  2. Hot Surface Igniter Replacement: Disconnect power, remove wires, replace unit
  3. Pressure Switch Testing: Use manometer to verify proper operation
  4. Blower Motor Replacement: Disconnect power, remove blower assembly, replace motor
  5. Gas Valve Replacement: Shut off gas, disconnect wiring and piping, replace valve
  6. Control Board Replacement: Document wiring, take photos, transfer all connections
  7. Heat Exchanger Inspection: Visual check for cracks or corrosion

WARNING! Always verify repair with proper testing before returning unit to service.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

FrequencyMaintenance Task
MonthlyCheck air filter; replace if dirty
SeasonalInspect vent system; clean flame sensor
AnnualProfessional inspection and cleaning
Every 2-3 YearsComplete system cleaning and calibration

Error Code Reference

Common error codes and their meanings for Rheem furnaces.

LED Flash PatternError CodeDescription
1 FlashPressure Switch ErrorCheck venting and pressure switch
2 FlashesIgnition FailureCheck gas supply and igniter
3 FlashesFlame Loss ErrorClean flame sensor
4 FlashesLimit Switch LockoutCheck airflow and filters
5 FlashesRollout Switch ErrorInspect heat exchanger
7 FlashesBlower ErrorCheck blower motor and capacitor

Parts Replacement

Proper procedures for replacing critical furnace components.

Authorized Parts: Use only Rheem-approved replacement parts

Warranty: Unauthorized parts may void manufacturer warranty

Availability: Contact Rheem distributor or authorized dealer

Cross-Reference: Verify part numbers match original specifications

Troubleshooting Guide

SymptomPossible CauseCorrective Action
Furnace won't startPower loss, thermostat issueCheck circuit breaker, thermostat settings and wiring
No heatGas supply, igniter failureVerify gas valve open, check igniter for continuity
Short cyclingDirty filter, limit switchReplace air filter, check limit switch operation
Blower won't stopThermostat fan settingCheck thermostat fan setting (Auto/On)
Unusual noisesLoose components, bearing wearInspect blower assembly, tighten mounting hardware
Pilot outage (standing pilot)Draft, thermocoupleCheck draft hood, replace thermocouple if weak

Reset Procedure: Power off for 30 seconds, then restore power

Technical Support: 1-800-432-8373; www.rheem.com

Rheem Furnace Repair Manual © - All Rights Reserved 2025