Guardian Furnace BCU05010A Manual

The Guardian Furnace BCU05010A is a high-efficiency gas furnace with 50,000 BTU output capacity, electronic ignition system, variable-speed blower motor, multi-speed operation, built-in diagnostic LED, safety shut-off features, and compatibility with standard thermostat systems. Designed for residential use with natural gas or propane conversion capability. 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. Specifications 5. Controls and Operation 6. Thermostat Connection 7. Maintenance Procedures 8. Safety Features 9. Care & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Gas valve assembly, heat exchanger, blower motor, igniter, flame sensor, pressure switches, diagnostic LED, filter compartment.

Feature	Description
Gas valve	For natural gas or propane operation
Heat exchanger	Stainless steel primary and secondary
Blower motor	Variable speed ECM motor
Ignition system	Hot surface igniter
Flame sensor	Safety flame detection
Pressure switches	Induced draft safety
Diagnostic LED	Error code display
Filter compartment	Standard 1-inch filter
Power switch	Unit on/off control
Gas connection	1/2" NPT gas inlet

Installation Requirements

Unpack and inspect all components. Ensure proper clearances and ventilation.

Location requirements: Minimum 1-inch clearance from combustible materials
Vent piping: Use approved PVC or ABS piping for intake and exhaust
Gas connection: Use approved gas pipe with drip leg and shut-off valve
Electrical: 120V AC, 60Hz dedicated circuit required
Thermostat wiring: Connect to standard 24V thermostat terminals

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.

Check gas supply: Ensure gas valve is open and pressure is correct
Verify electrical: Confirm 120V power and proper grounding
Test operation: Set thermostat to heat mode above room temperature
Check airflow: Verify proper airflow through registers
Monitor ignition: Observe startup sequence for proper operation

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

Specifications

Heating Capacity: 50,000 BTU/h
Efficiency: 95% AFUE
Gas Type: Natural gas (convertible to propane)
Electrical: 120V AC, 60Hz, 5 Amps
Blower Motor: Variable speed ECM
Vent Size: 2-inch PVC/ABS
Gas Connection: 1/2" NPT
Dimensions: Standard upflow configuration
Operating Temp Range: -30°F to 120°F

Controls and Operation

Access control board via front panel. LED indicator shows operational status.

Control Board: Power switch, diagnostic LED, thermostat terminals, gas valve connector.

Operation sequence: Thermostat call for heat, inducer motor starts, pressure switch confirms, igniter heats, gas valve opens, flame sensor confirms, blower starts after delay. Diagnostic codes: Steady green = normal operation, flashing codes indicate specific faults.

Thermostat Connection

Standard 24V thermostat connection with R, W, G, C terminals.

Turn off power before connecting thermostat wires
Match thermostat wires to control board terminals
Use 18-gauge thermostat wire for connections
Program thermostat for proper heating cycles

Tip: Ensure thermostat is located away from heat sources and drafts.

Maintenance Procedures

Regular maintenance ensures optimal performance and safety.

Monthly: Check and replace air filter as needed
Seasonal: Inspect vent system for obstructions
Annual: Professional inspection of heat exchanger, burners, and safety devices
Bi-annual: Clean flame sensor and inspect igniter
As needed: Check condensate drain for blockages

WARNING! Always turn off power and gas supply before performing maintenance.

Safety Features

Multiple safety systems: Flame rollout switch, high limit switch, pressure switches, flame sensor, igniter safety lockout.

Care & Cleaning

Turn off power before cleaning. Use soft brush and vacuum for dust removal.

CAUTION! Never use water or cleaning chemicals on electrical components. Keep area around furnace clear of combustible materials.

Regulatory Information

UL certified for safety standards. ANSI Z21.47 compliant for gas appliances. CSA certified for Canadian standards. Manufactured to meet DOE efficiency requirements. For technical support, contact Guardian Heating & Cooling at 1-800-555-HEAT or visit www.guardianheating.com.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Furnace won't start	Power/thermostat	Check circuit breaker; verify thermostat settings; ensure door switch engaged.
No heat	Gas supply/ignition	Verify gas valve open; check for ignition failure; inspect flame sensor.
Short cycling	Airflow/filter	Replace dirty filter; check for blocked vents; verify proper airflow.
Blower not running	Motor/control	Check blower motor operation; verify control board signals; inspect capacitor.
Error code flashing	System fault	Refer to diagnostic chart; count LED flashes for specific error code.

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

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