Horizontal Furnace Installation Manual

The Horizontal Furnace is a high-efficiency heating system designed for horizontal installation in attics, crawl spaces, or other confined areas. This unit features variable-speed blower technology, electronic ignition, multi-speed operation, safety shut-off controls, and compatibility with various thermostat systems. Below are key sections for safety, installation procedures, electrical connections, startup, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Horizontal furnace unit, blower assembly, heat exchanger, gas valve, control board, limit switches, and access panels.

Safety Precautions

Critical safety information for proper installation and operation.

1. Turn off electrical power and gas supply before beginning installation.
2. Wear appropriate personal protective equipment (safety glasses, gloves).
3. Ensure adequate ventilation and combustion air supply.
4. Verify clearances to combustible materials as specified in manual.
5. Use only approved materials for gas line and electrical connections.

WARNING! Failure to follow safety precautions may result in fire, explosion, carbon monoxide poisoning, or personal injury. Installation must comply with all local codes and regulations.

Pre-Installation Requirements

Site preparation and verification before installation begins.

1. Verify installation location meets clearance requirements (minimum 1" sides, 6" top, 24" front).
2. Ensure structural support is adequate for furnace weight (typically 80-120 lbs).
3. Check that electrical service meets furnace requirements (typically 15-20 amp circuit).
4. Verify gas line size and pressure meet specifications (typically 1/2" to 3/4" pipe).
5. Confirm venting route meets code requirements for horizontal installation.

CAUTION! Improper site preparation may void warranty and create safety hazards.

Installation Procedures

Step-by-step installation instructions for horizontal furnace.

1. Position furnace: Place unit on approved mounting brackets or platform.
2. Level furnace: Ensure unit is level in both directions for proper drainage.
3. Secure mounting: Fasten furnace to structure using appropriate hardware.
4. Install filter rack: Mount filter access on return air side.
5. Connect ductwork: Attach supply and return ducts using approved methods.
6. Install venting: Connect flue pipes according to manufacturer specifications.
7. Connect gas line: Use approved pipe compound and test for leaks.
8. Make electrical connections: Follow wiring diagram precisely.
9. Install thermostat: Connect control wiring to appropriate terminals.
10. Final inspection: Verify all connections and clearances.

Electrical Connections

Wiring requirements and connection procedures.

• Power Supply: 120V/60Hz or 240V/60Hz as specified
• Circuit Protection: 15-20 amp circuit breaker
• Grounding: Proper equipment grounding required
• Thermostat Wiring: Standard 5-wire or 8-wire connection
• Blower Speeds: Multi-tap wiring for cooling/heating speeds

WARNING! Electrical work must be performed by qualified personnel. Turn off power before making connections.

Ductwork Installation

Proper duct connection for horizontal airflow.

1. Size ducts according to furnace capacity and system requirements.
2. Use rigid metal or approved flexible duct materials.
3. Ensure proper sealing at all connections to prevent air leakage.
4. Install balancing dampers if required for system balancing.
5. Verify adequate return air capacity for proper furnace operation.

Tip: Proper duct sizing and sealing are critical for system efficiency and performance.

Gas Line Connections

Natural gas or propane connection procedures.

1. Use black iron pipe or approved flexible gas connector.
2. Apply pipe compound only to male threads.
3. Install sediment trap before gas valve connection.
4. Use two wrenches to prevent twisting gas valve.
5. Pressure test entire gas line before connecting to furnace.
6. Verify gas pressure at manifold (typically 3.5" WC natural gas).

WARNING! Gas line installation must be performed by licensed professional. Leak test with soap solution.

Venting Requirements

Proper venting for horizontal furnace installation.

• Vent Material: Category I or III approved vent pipe
• Clearances: Maintain 1" clearance to combustibles
• Slope: 1/4" per foot upward toward termination
• Termination: Approved wall cap with proper clearance
• Length: Maximum vent run as specified in manual
• Combustion Air: Provide adequate makeup air

Startup and Commissioning

Final checks and system startup procedures.

1. Verify all electrical and gas connections are secure.
2. Check gas pressure at manifold port.
3. Set blower speeds for heating and cooling modes.
4. Test ignition sequence and flame verification.
5. Measure temperature rise across heat exchanger.
6. Check for proper condensate drainage (if applicable).
7. Verify thermostat operation and temperature calibration.
8. Complete startup checklist and record measurements.

CAUTION! Never bypass safety controls during startup. Follow all manufacturer procedures.

Maintenance Schedule

Recommended maintenance for optimal performance.

Troubleshooting

Reset Procedure: Turn power off for 30 seconds, then restore. Check error codes on control board.

Service: Contact qualified HVAC technician for complex issues. Refer to manufacturer warranty.