Free Owners Manual for a Intertherm Furnace FEHA

The Intertherm FEHA furnace is a high-efficiency gas furnace designed for residential heating applications. This furnace features advanced combustion technology, multiple safety systems, variable-speed blower motor, electronic ignition, and compatibility with various thermostat systems. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation Requirements 3. First-Time Setup 4. Technical Specifications 5. Controls and Operation 6. Maintenance Schedule 7. Safety Systems 8. Troubleshooting Guide 9. Warranty Information 10. Regulatory Compliance 11. Professional Service

Features at a Glance

Key components: High-efficiency heat exchanger, variable-speed blower motor, electronic ignition system, multi-speed inducer motor, integrated control board, safety switches, and flue gas venting system.

FeatureDescription
Heat ExchangerStainless steel construction for maximum efficiency and durability
Blower MotorVariable-speed ECM motor for quiet operation and energy savings
Ignition SystemHot surface electronic ignition for reliable startup
Inducer MotorMulti-speed draft inducer for proper combustion air flow
Control BoardIntegrated microprocessor for system monitoring and control
Safety SwitchesPressure switches, rollout switches, and high-limit controls
Venting SystemPVC pipe compatible for sidewall or roof venting
Filter SystemStandard 1-inch or optional 4-inch media filter capability
Gas ValveModulating gas valve for precise temperature control
Thermostat CompatibilityWorks with conventional and programmable thermostats

Installation Requirements

Professional installation required. Ensure proper clearances and venting.

  1. Location: Install in well-ventilated area with proper clearances (minimum 1 inch from combustible materials).
  2. Venting: Use approved PVC piping for combustion air and flue gas venting.
  3. Gas Connection: Use black iron pipe with proper thread sealant; pressure test required.
  4. Electrical: 120V AC power supply with proper grounding; dedicated circuit recommended.
  5. Drain Line: Install condensate drain line with proper slope and trap.

WARNING! Installation must be performed by qualified HVAC technician. Improper installation can cause fire, explosion, or carbon monoxide poisoning.

First-Time Setup

Initial startup must be performed by qualified technician.

  1. System Check: Verify all connections are secure and proper.
  2. Gas Pressure: Adjust gas valve to manufacturer specifications.
  3. Venting: Confirm proper draft and combustion air flow.
  4. Electrical: Verify correct voltage and proper grounding.
  5. Test Operation: Run through complete heating cycle; check for proper operation and safety system function.

CAUTION! Never attempt to adjust gas pressure or electrical connections without proper training and equipment.

Technical Specifications

Controls and Operation

Integrated control board manages all furnace functions. Status lights indicate system operation and fault codes.

Normal Operation: Thermostat calls for heat → inducer motor starts → pressure switch closes → hot surface igniter heats → gas valve opens → main burner ignition → blower motor starts after heat exchanger warms.

LED Status Codes: Green (normal operation), Red (fault condition - blink pattern indicates specific issue).

Thermostat Settings: Set desired temperature; furnace will cycle automatically to maintain setting.

Maintenance Schedule

Regular maintenance ensures optimal performance and safety.

  1. Monthly: Check and replace air filter if dirty
  2. Seasonal: Visual inspection of vent pipes and drain lines
  3. Annual: Professional inspection and cleaning including:
    • Heat exchanger inspection
    • Burner cleaning and adjustment
    • Blower motor and wheel cleaning
    • Safety system testing
    • Gas pressure verification

Tip: Keep area around furnace clean and free of combustible materials.

Safety Systems

Multiple safety features protect against hazardous conditions.

Safety FeatureFunction
Flame Rollout SwitchDetects flame outside combustion chamber
High Limit SwitchPrevents overheating of heat exchanger
Pressure SwitchesVerify proper inducer operation and venting
Flame SensorConfirms burner ignition; shuts off gas if no flame
Gas ValveAutomatic shutoff if ignition fails
Condensate SafetyPrevents operation if drain is blocked

WARNING! Never bypass safety devices. If safety switch trips repeatedly, contact qualified service technician.

Troubleshooting Guide

SymptomPossible CauseCorrective Action
Furnace won't startPower, thermostat, door switchCheck circuit breaker; verify thermostat setting; ensure door properly closed
No heatGas supply, ignition, filterCheck gas valve; verify pilot/ignition; replace dirty filter
Short cyclingDirty filter, airflow, high limitReplace filter; check vents and registers; inspect high limit switch
Blower runs continuouslyThermostat setting, control boardCheck thermostat fan setting; inspect control board
Unusual noisesMotor bearings, ductwork, airflowLubricate if required; check for loose panels; verify proper airflow
Error code flashingVarious system faultsRefer to LED blink pattern in service manual; contact technician if unresolved

Warranty Information

Limited warranty coverage varies by model and installation date.

Warranty requires professional installation and annual maintenance by qualified technician. Keep original receipt and maintenance records.

Regulatory Compliance

UL certified; meets ANSI Z21.47 standards for gas-fired central furnaces. CSA certified for Canadian installations. Complies with Department of Energy efficiency standards. Manufactured to meet or exceed all applicable safety and performance requirements.

Professional Service

For service, contact qualified HVAC technician. Have model and serial numbers ready when calling for service.

Model Number: Located on rating plate inside furnace cabinet

Serial Number: Located on rating plate; required for warranty service

Technical Support: Available through manufacturer's website or authorized service centers

Emergency: If you smell gas, leave building immediately and call gas company from outside

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