Coleman Furnace Model 7956A856 Manual

The Coleman Furnace Model 7956A856 is a high-efficiency gas furnace designed for residential heating applications. This model features advanced combustion technology, multiple heat stages, variable-speed blower motor, electronic ignition, built-in diagnostics, and compatibility with standard thermostat systems. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation Requirements 3. Initial Setup & Startup 4. Technical Specifications 5. Controls and Operation 6. Thermostat Connection 7. Maintenance Procedures 8. Safety Features 9. Cleaning & Care 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Heat exchanger, blower assembly, gas valve, control board, ignition system, pressure switches, flame sensor, and venting system.

Feature	Description
Heat Exchanger	Stainless steel primary and secondary heat exchangers
Blower Motor	Variable-speed ECM motor for efficient airflow
Gas Valve	Multi-stage gas valve for precise heating control
Control Board	Microprocessor-based with diagnostic LED indicators
Ignition System	Hot surface ignition for reliable startup
Pressure Switches	Safety switches for proper venting operation
Flame Sensor	Monitors burner flame during operation
Venting	PVC vent pipe compatible
Filter System	Standard 1-inch or 4-inch media filter compatible
Thermostat Connection	Standard 24VAC connection terminals

Installation Requirements

Professional installation required. Verify local codes and obtain necessary permits.

Location: Install in dry, well-ventilated area with proper clearances.
Gas Connection: Use approved gas piping; pressure test for leaks.
Electrical: 120VAC power supply with proper grounding.
Venting: Install PVC vent pipes according to manufacturer specifications.
Drainage: Connect condensate drain line to proper drainage.

WARNING! Gas appliances can be dangerous if improperly installed. Use qualified HVAC technician for installation.

Initial Setup & Startup

After installation, perform initial startup procedure.

Verify all connections: Gas, electrical, venting, and drainage.
Install air filter: Ensure proper size and orientation.
Power on: Turn on electrical power and gas supply.
Test operation: Set thermostat to heat mode and verify proper ignition.
Check airflow: Verify adequate airflow from all registers.
Monitor operation: Observe complete heating cycle for proper function.

CAUTION! Never bypass safety devices. If furnace fails to start, contact qualified technician.

Technical Specifications

Heating Capacity: 80,000 BTU/hr input
Efficiency: 95% AFUE
Gas Type: Natural Gas (convertible to LP with kit)
Gas Pressure: 3.5" WC natural gas, 10" WC propane
Electrical: 120VAC, 60Hz, 5 amps
Airflow: 1200-2000 CFM variable
Stages: Two-stage heating operation
Sound Level: < 65 dBA
Dimensions: 21" W x 56" H x 26" D
Weight: 125 lbs

Controls and Operation

Access control board via front panel. LED status lights indicate system operation.

Control Board Indicators: Power (green), Heat (yellow), Fan (blue), Fault (red).

Operation Modes: HEAT, COOL, FAN ONLY, OFF. Blower Speeds: Adjustable for heating and cooling modes. Temperature Control: Set via connected thermostat. Diagnostic Codes: Flash patterns indicate specific fault conditions.

Thermostat Connection

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

Turn off power to furnace before connecting thermostat.
Connect thermostat wires to corresponding terminals.
Use 18-gauge thermostat wire for proper connection.
Program thermostat according to manufacturer instructions.

Tip: For optimal performance, use programmable thermostat with multi-stage capability.

Maintenance Procedures

Regular maintenance ensures optimal performance and longevity.

Monthly: Check and replace air filter as needed.
Seasonal: Inspect burners and heat exchanger for debris.
Annual: Professional inspection and cleaning recommended.
Blower Maintenance: Clean blower wheel and motor annually.
Vent System: Inspect vent pipes for obstructions.
Drainage: Clear condensate drain line and trap.

WARNING! Turn off power and gas supply before performing any maintenance.

Safety Features

Multiple safety systems protect against hazardous conditions: High limit switch, flame rollout switch, pressure switches, flame sensor, ignition control lockout, condensate overflow switch.

Cleaning & Care

Keep furnace area clean and free of combustible materials. Use soft brush and vacuum for cleaning components.

CAUTION! Never use water or cleaning solvents on electrical components. Keep ventilation openings clear.

Regulatory Information

UL certified for safety standards. ANSI Z21.47 compliant. Meets DOE energy efficiency requirements. Manufactured to ISO 9001 quality standards. For technical support, contact Coleman HVAC at 1-800-445-8292 or visit www.colemanac.com.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Furnace won't start	Power, thermostat, safety switch	Check power supply; verify thermostat settings; reset door switch.
No heat	Gas supply, ignition, filter	Verify gas valve on; check for ignition; replace dirty filter.
Short cycling	Filter, thermostat, limit switch	Clean/replace filter; check thermostat location; verify proper airflow.
Blower not running	Power, motor, control board	Check electrical connections; test blower motor; inspect control board.
Unusual noises	Blower, motor, ductwork	Inspect blower wheel; check motor bearings; examine duct connections.

Reset: Turn power off for 30 seconds, then restore power.

Service: 1-800-445-8292; www.colemanac.com