Ducane Model PGA100B4 Furnace Manual

The Ducane Model PGA100B4 is a high-efficiency gas furnace designed for residential heating applications. This 100,000 BTU unit features a multi-speed blower, electronic ignition, and safety controls. 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 Settings 6. Venting and Combustion Air 7. Operating Instructions 8. Maintenance Schedule 9. Safety Features 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Gas valve, heat exchanger, blower assembly, electronic ignition, pressure switches, limit controls.

Feature	Description
Input Capacity	100,000 BTU/h
Efficiency	80% AFUE
Blower Type	Multi-speed direct drive
Ignition System	Hot surface electronic ignition
Gas Type	Natural gas
Venting	Category I vertical or horizontal
Electrical	115V, 60Hz
Dimensions	See specifications section
Safety Controls	Flame rollout, limit switches, pressure switches
Warranty	20-year heat exchanger, 5-year parts

Installation Requirements

Professional installation required. Verify local codes and obtain permits.

Location: Install in approved locations with proper clearances to combustibles.
Gas Connection: Use black iron pipe; test for leaks with soap solution.
Electrical: Connect to dedicated 115V circuit with proper grounding.
Venting: Install approved vent pipe with proper slope and termination.
Combustion Air: Provide adequate fresh air supply per local codes.

WARNING! Gas furnaces produce carbon monoxide. Proper installation and venting are critical for safety.

First-Time Startup

After installation, perform initial startup procedure.

Verify all connections: Gas, electrical, venting, and air ducts.
Set thermostat to lowest setting.
Turn gas valve to ON position.
Turn on electrical power to furnace.
Set thermostat to call for heat and observe ignition sequence.
Check for proper flame and verify temperature rise within specifications.

CAUTION! Only qualified HVAC technicians should perform startup procedures.

Specifications

Model: PGA100B4
Input BTU: 100,000 BTU/h
Output BTU: 80,000 BTU/h
AFUE: 80%
Gas Pressure: 3.5" WC natural gas
Electrical: 115V, 60Hz, 6.5 amps
Blower Speeds: 4 speeds for heating/cooling
Dimensions (HxWxD): 44" x 17.5" x 25.5"
Vent Size: 5" diameter
Weight: 125 lbs

Controls and Settings

Integrated control board manages all furnace operations with LED status indicators.

Control Board: Monitors safety devices, controls ignition sequence, manages blower operation.

Thermostat Connections: R, W, G, Y, C terminals. Blower Speeds: Adjustable for heating and cooling modes. Limit Switches: High temperature protection. Pressure Switches: Verify proper venting. Gas Valve: Regulates gas flow with manual shutoff.

Venting and Combustion Air

Proper venting is essential for safe operation.

Vent Pipe: Use approved B-vent or listed vent material.
Vent Termination: Minimum 12" from building openings.
Combustion Air: Provide adequate fresh air per installation instructions.
Clearances: Maintain required clearances to combustibles.

Tip: Inspect vent system annually for obstructions or deterioration.

Operating Instructions

Normal operation controlled by thermostat.

Set thermostat to desired temperature.
Furnace will automatically cycle on and off to maintain temperature.
Blower will operate during heating cycle and continue for post-purge.
For continuous fan operation, set thermostat to FAN ON position.

WARNING! Never operate furnace with access panels removed.

Maintenance Schedule

Annual professional maintenance recommended.

Monthly: Check air filter, replace if dirty
Annual: Professional inspection and cleaning
Every 2 years: Inspect heat exchanger for cracks
As needed: Clean flame sensor, check gas pressure

CAUTION! Turn off power and gas before performing any maintenance.

Safety Features

Multiple safety devices protect against hazardous conditions.

Safety Device	Function
Flame Rollout Switch	Detects flame outside combustion chamber
High Limit Switch	Shuts off gas if temperatures exceed safe limits
Pressure Switch	Verifies proper venting before ignition
Flame Sensor	Confirms flame presence during operation
Gas Valve	Automatic shutoff if ignition fails

Regulatory Information

ANSI Z21.47: Certified for natural gas operation. UL Listed: Meets safety standards. Installation must comply with National Fuel Gas Code NFPA 54 and local building codes. For technical support, contact Ducane at 1-800-338-0070 or visit www.ducanehvac.com.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Furnace won't start	Power, thermostat, safety lockout	Check power switch, thermostat setting, reset furnace
No heat	Gas supply, ignition failure	Verify gas valve on, check for ignition attempts
Short cycling	Dirty filter, limit switch	Replace air filter, check for restricted airflow
Blower won't stop	Thermostat setting, control board	Check thermostat fan setting, inspect control board
Unusual noises	Loose components, airflow	Inspect blower wheel, check ductwork for restrictions

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

Service: 1-800-338-0070; www.ducanehvac.com