Dependable Ninety Two Furnace Manual

The Dependable Ninety Two Furnace is a high-efficiency gas furnace with 92% AFUE rating, featuring variable-speed blower motor, electronic ignition, multi-speed operation, built-in diagnostics, safety controls, and compatibility with standard thermostats. Designed for residential heating applications with natural gas or propane capability. Below are key sections for safety, features, installation, setup, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Connecting Thermostat 7. Operation 8. Maintenance Procedures 9. Safety Features 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Stainless steel heat exchanger, variable-speed blower, electronic ignition system, pressure switches, flame sensor, gas valve, filter compartment, and diagnostic LED.

FeatureDescription
Heat ExchangerStainless steel primary and secondary
Blower MotorVariable-speed ECM for efficiency
Ignition SystemHot surface electronic ignition
Gas ValveModulating for precise temperature control
Filter SystemStandard 1-inch or 4-inch media filter
Diagnostic LEDFlashing codes for troubleshooting
Pressure SwitchesSafety verification of venting
Flame SensorMonitors burner operation
Limit SwitchesPrevents overheating
Drain SystemCondensate removal for high-efficiency operation

Installation

Unpack and inspect all components. Ensure proper clearances and venting requirements.

  1. Position furnace: Place on level surface with proper clearances (6 inches minimum from combustible materials).
  2. Install venting: Use approved PVC for intake and exhaust; maintain proper slope for condensate drainage.
  3. Connect gas supply: Use black iron pipe with drip leg; pressure test for leaks.
  4. Electrical connections: Connect 120V power and thermostat wiring.
  5. Install condensate drain: Route to suitable drain location.

WARNING! Gas appliances can be dangerous; only qualified technicians should perform installation. Follow all local codes.

First-Time Setup

After installation, perform initial startup procedure.

  1. Verify gas pressure: Check manifold pressure (3.5" WC natural gas / 10" WC propane).
  2. Check electrical: Verify proper voltage and grounding.
  3. Test safety controls: Verify operation of limit switches and pressure switches.
  4. Startup sequence: Turn on power and gas; observe ignition sequence.
  5. Adjust blower speeds: Set heating CFM according to duct system requirements.

CAUTION! Never bypass safety controls. Ensure proper ventilation during operation.

Specifications

Controls and Settings

Integrated control board with diagnostic capabilities. Access via control panel cover removal.

Control Board Features: Status LED, dip switches for configuration, terminal strip for thermostat connections.

Blower Speeds: Adjustable for heating and continuous fan operation. Gas Pressure: Field adjustable for altitude and gas type. Temperature Rise: Adjustable within 35-65°F range. Diagnostic Codes: LED flash patterns indicate specific faults.

Connecting Thermostat

Compatible with standard 24V thermostats. Wiring terminals: R, C, W, G, Y.

  1. Turn off power to furnace before wiring.
  2. Connect thermostat wires to control board terminals.
  3. Use 18-gauge thermostat wire for runs under 50 feet.
  4. Configure thermostat for single-stage heating.

Tip: For optimal performance, use programmable thermostat with temperature compensation.

Operation

Normal heating cycle operation and features.

  1. Thermostat call: Thermostat calls for heat, sending 24V signal.
  2. Inducer operation: Inducer motor starts and pressure switch verifies.
  3. Ignition sequence: Hot surface igniter glows, gas valve opens.
  4. Flame verification: Flame sensor confirms ignition.
  5. Blower operation: Blower starts after heat exchanger warm-up delay.
  6. Cycle completion: Thermostat satisfied, gas valve closes, blower continues for cool-down.

WARNING! Never operate furnace without filter. Keep combustion air openings clear.

Maintenance Procedures

Regular maintenance ensures optimal performance and safety.

CAUTION! Always turn off power and gas before performing maintenance.

Safety Features

Multiple safety systems protect against hazardous conditions.

Safety FeatureFunction
Flame Rollout SwitchesDetects improper burner combustion
High Limit SwitchesPrevents overheating of heat exchanger
Pressure SwitchesVerifies proper venting operation
Flame SensorConfirms burner ignition
Gas ValveAutomatic shutoff if ignition fails
Condensate OverflowShuts down furnace if drain blocked

Regulatory Information

UL listed and ANSI Z21.47 compliant. Certified for US and Canadian installation. Meets Department of Energy efficiency standards. Natural gas models certified for altitudes up to 2000 feet; propane models up to 4500 feet. For technical support, contact Dependable Heating Products at 1-800-555-HEAT or visit www.dependablefurnace.com.

Troubleshooting

SymptomPossible CauseCorrective Action
Furnace won't startPower, thermostat, door switchCheck circuit breaker; verify thermostat setting; ensure door switch engaged.
No heatGas supply, ignitionVerify gas valve on; check for ignition attempts; inspect flame sensor.
Short cyclingFilter, limit switchReplace dirty filter; check for blocked vents; verify proper airflow.
Blower won't stopThermostat fan settingCheck thermostat fan setting (auto/on); inspect control board.
Error codes flashingVarious faultsCount LED flashes and refer to diagnostic chart in service manual.
Condensate leakageDrain blockageClear condensate drain line; check trap for debris.

Reset: Power cycle furnace by turning off power for 30 seconds.

Service: 1-800-555-HEAT; www.dependablefurnace.com

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