Inter-City GNI Furnace Manual

The Inter-City GNI Furnace is a high-efficiency gas furnace designed for residential heating applications. This model features advanced combustion technology, multiple heating stages, variable-speed blower motor, smart thermostat compatibility, safety shut-off systems, and energy-saving modes. 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. Operating Modes 8. Safety Features 9. Maintenance & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Gas valve assembly, heat exchanger, blower motor, igniter, flame sensor, pressure switches, control board, air filter compartment.

Feature	Description
Gas valve	Precise gas flow control for efficient combustion
Heat exchanger	Stainless steel construction for durability and heat transfer
Blower motor	Variable-speed ECM motor for quiet operation
Igniter system	Hot surface igniter for reliable ignition
Flame sensor	Safety device to detect flame presence
Pressure switches	Monitor combustion air and venting
Control board	Microprocessor for system operation and diagnostics
Filter access	Easy-access panel for filter replacement
Diagnostic lights	LED indicators for troubleshooting
Safety shut-off	Automatic gas shut-off in case of malfunction

Installation

Unpack and inspect all components. Ensure proper location with adequate clearance.

Position furnace: Place on stable, level surface with proper clearances as specified.
Gas connection: Use approved gas piping; pressure test for leaks before operation.
Electrical connection: Connect to dedicated 120V circuit with proper grounding.
Vent system: Install approved vent piping according to local codes.
Air intake: Ensure proper combustion air supply as per installation manual.

WARNING! Installation must be performed by qualified HVAC technician. Gas leaks can cause explosion or fire.

First-Time Setup

Power on furnace; follow startup sequence.

Thermostat wiring: Connect compatible thermostat following wiring diagram.
Gas pressure adjustment: Verify and adjust gas pressure to specifications.
Blower speed settings: Set appropriate speeds for heating and continuous fan.
System check: Run through complete heating cycle to verify operation.
Safety testing: Test all safety controls and limit switches.

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

Specifications

Heating Capacity: 60,000 - 120,000 BTU/h (model dependent)
Efficiency: Up to 96% AFUE
Gas Type: Natural gas or LP (conversion kit required)
Electrical: 120V AC, 60Hz, 15A circuit
Stages: Single or two-stage heating (model dependent)
Blower Type: Variable-speed ECM
Vent Material: PVC or ABS (category IV)
Filter Size: Standard 16x25x1 inch or 20x25x1 inch
Sound Level: Less than 75 dB during operation
Warranty: 10-year heat exchanger, 5-year parts

Controls and Settings

Access control board via front service panel. Diagnostic lights indicate system status.

Thermostat Controls: HEAT/COOL/OFF mode, temperature setting, fan AUTO/ON, system programming.

Heating Stages: Single-stage or two-stage operation based on demand. Blower Settings: Multiple speed taps for heating and continuous fan. Diagnostic Codes: LED flash patterns indicate specific error conditions. Limit Controls: High-limit switch protects against overheating. Pressure Switches: Ensure proper venting and combustion air flow.

Connecting Thermostat

Compatible with most 24VAC thermostats. Follow wiring diagram for proper connections.

Turn off power to furnace before wiring thermostat.
Identify terminals: R (power), W (heat), G (fan), C (common), Y (cooling).
Connect thermostat wires to corresponding control board terminals.
Program thermostat for desired temperature settings and schedules.

Tip: Use programmable thermostat for maximum energy savings.

Operating Modes

Supports multiple operating modes for comfort and efficiency.

Heating Mode: Primary heating operation with single or two-stage capability.
Fan Only: Continuous or intermittent blower operation for air circulation.
Standby: System ready but not actively heating.
Diagnostic: Service mode for troubleshooting and testing.
Lockout: Safety mode when fault conditions are detected.

WARNING! Do not operate furnace with access panels removed. Keep combustibles away from furnace.

Safety Features

Flame Rollout Switch: Detects improper burner flames. High Limit Switch: Prevents overheating. Pressure Switches: Ensure proper vent operation. Ignition Control: Safe lighting sequence. Gas Valve: Automatic shut-off during faults.

Maintenance & Cleaning

Turn off power and gas supply before maintenance. Replace air filter monthly during heating season. Clean burners and heat exchanger annually. Inspect vent system for obstructions.

CAUTION! Carbon monoxide hazard - ensure proper venting. Only qualified technicians should service gas components.

Regulatory Information

ANSI Z21.47: Certified for gas-fired central furnaces. UL 1995: Standard for heating and cooling equipment. CSA International: Certified for Canadian standards. For support, visit www.inter-cityfurnace.com or contact 1-800-555-HEAT.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Furnace won't start	Power/thermostat	Check circuit breaker; verify thermostat settings; ensure gas valve open.
No heat	Ignition/pilot	Check for spark at igniter; verify gas supply; inspect flame sensor.
Short cycling	Filter/limits	Replace dirty air filter; check high-limit switch; verify proper airflow.
Blower not running	Motor/controls	Check blower capacitor; verify control board signals; inspect motor.
Unusual noises	Components/wear	Inspect blower wheel; check heat exchanger; lubricate motor if applicable.

Reset: Power cycle furnace to clear temporary lockouts.

Service: 1-800-555-HEAT; www.inter-cityfurnace.com