Arcoaire Furnace Service Manual

The Arcoaire Furnace is a high-efficiency residential heating system designed for reliable performance and energy savings. This service manual covers installation, operation, maintenance, and troubleshooting procedures for certified HVAC technicians. The furnace features variable-speed blower motors, electronic ignition systems, advanced diagnostic controls, and multiple safety features including flame rollout switches and pressure switches.

1. Safety Precautions 2. Technical Specifications 3. Installation Procedures 4. Electrical Connections 5. Gas Line Connections 6. Venting Requirements 7. Startup and Commissioning 8. Operating Instructions 9. Maintenance Procedures 10. Diagnostic Codes 11. Troubleshooting Guide

Safety Precautions

Critical safety information for installation and service technicians.

HazardPrecaution
Electrical ShockDisconnect power before servicing; use lockout/tagout procedures
Gas LeaksUse leak detection solution; never use open flame to check for leaks
Carbon MonoxideEnsure proper venting; test with CO detector after installation
Hot SurfacesAllow unit to cool before servicing heat exchanger components
Moving PartsDisconnect power before working on blower assembly
Combustible MaterialsMaintain clearances per installation instructions

Technical Specifications

Installation Procedures

Proper installation ensures safe and efficient operation.

  1. Location Selection: Choose area with adequate combustion air and service clearance
  2. Unit Placement: Level unit on solid foundation; ensure proper clearances to combustibles
  3. Ductwork Connection: Seal all duct connections with approved mastic or tape
  4. Filter Installation: Install proper size filter; arrow indicating airflow direction
  5. Thermostat Wiring: Connect to R, W, G, C terminals as required

WARNING! Installation must comply with local codes and manufacturer specifications. Only qualified technicians should perform installation.

Electrical Connections

Proper electrical connections are critical for safe operation.

  1. Disconnect all power sources before making electrical connections
  2. Verify voltage matches unit requirements (115V or 208-230V)
  3. Connect line voltage to designated terminals in control box
  4. Route low voltage thermostat wires through separate knockout
  5. Install properly sized fuses or circuit breakers as required
  6. Ground unit according to local electrical codes

CAUTION! Reverse polarity can damage control board. Verify wiring before energizing.

Gas Line Connections

Gas piping must be properly sized and installed.

  1. Shut off gas supply at main valve before beginning work
  2. Install sediment trap ahead of gas valve
  3. Use approved pipe thread sealant suitable for gas service
  4. Pressure test gas line at 14" W.C. for 10 minutes (no drop)
  5. Connect flexible gas connector if local codes permit
  6. Check manifold pressure at gas valve (3.5" W.C. natural gas)

DANGER! Gas leaks can cause explosion or fire. Test all connections with leak detection solution.

Venting Requirements

Proper venting is essential for safe operation and efficiency.

Vent TypeRequirements
Category IVertical metal vent; minimum height above roof
Category IVPVC/CPVC pipe; specific slope requirements
Direct VentSeparate intake and exhaust; specific clearances

Ensure vent pipes are properly supported and sealed. Maintain clearances from windows, doors, and air intakes.

Startup and Commissioning

Follow this sequence for proper unit startup.

  1. Verify all connections are complete and secure
  2. Restore electrical power and gas supply
  3. Set thermostat to heating mode and raise temperature setting
  4. Observe ignition sequence: inducer motor, pressure switch, HSI, gas valve
  5. Check flame appearance (should be steady blue)
  6. Measure temperature rise across heat exchanger
  7. Verify proper airflow and duct temperatures
  8. Test safety controls and limit switches

Operating Instructions

Normal operating characteristics and user controls.

Thermostat Settings: Programmable thermostats should be set for energy efficiency. Recommended setback: 68°F daytime, 62°F nighttime.

Blower Operation: Variable speed blower adjusts airflow based on heating demand for optimal comfort and efficiency.

Pilot Light: Electronic ignition - no standing pilot. System ignites only when heat is called for.

Maintenance Procedures

Regular maintenance ensures longevity and efficiency.

  1. Monthly: Check and replace air filter as needed
  2. Annual: Professional inspection and cleaning
  3. Clean blower wheel and housing
  4. Inspect heat exchanger for cracks or corrosion
  5. Check burners for proper flame pattern
  6. Verify gas pressure and temperature rise
  7. Lubricate motors if required (most are permanently lubricated)
  8. Check condensate drain system on high-efficiency models

Diagnostic Codes

Control board LED flash codes for troubleshooting.

Flash PatternFault CodeDescription
1 FlashLockoutIgnition failure
2 FlashesPressure SwitchPressure switch stuck open
3 FlashesLimit CircuitHigh limit switch open
4 FlashesInducerInducer motor fault
5 FlashesFlame SenseFlame sensed with gas valve off
ContinuousNormalUnit operating normally

Troubleshooting Guide

SymptomPossible CauseCorrective Action
No heatThermostat, power, gas valveCheck thermostat setting; verify power; check gas valve operation
Blower won't runMotor, capacitor, control boardTest motor windings; check capacitor; verify control board output
Short cyclingDirty filter, limit switchReplace filter; check limit switch; verify airflow
Unusual noisesBlower wheel, inducer motorInspect for debris; check motor bearings; tighten components
Gas odorGas leak, improper combustionImmediately shut off gas; check for leaks; verify combustion
Pilot outageDraft, thermocoupleCheck venting; test thermocouple output; clean pilot assembly

Reset Procedure: Turn thermostat off, disconnect power for 30 seconds, restore power, reset thermostat.

Technical Support: 1-800-ARCOAIRE; www.arcoaire.com

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