Coleman Furnace Manual DGAA070BDTA

The Coleman DGAA070BDTA is a 70,000 BTU gas furnace with upflow/horizontal airflow configuration, single-stage natural gas operation, multi-speed blower, electronic ignition, aluminized steel heat exchanger, and compatibility with standard thermostat controls. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Connecting Thermostat 7. Operation 8. Maintenance 9. Care & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

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

Feature	Description
Heat Exchanger	Aluminized steel construction for durability
Blower Motor	Multi-speed ECM motor for efficient airflow
Ignition System	Hot surface igniter with flame sensor
Gas Valve	Single-stage natural gas operation
Airflow Configuration	Upflow/Horizontal compatible
Control Board	Integrated furnace controller with LED status lights
Pressure Switches	Safety switches for combustion air proving
Filter Rack	Standard 1-inch filter compatibility
Venting	Category I venting for natural draft
Thermostat Connection	Standard 24VAC thermostat terminals

Installation

Unpack and inspect contents. Ensure proper location with adequate clearance.

Position furnace: Install in upflow or horizontal position with proper clearances.
Connect gas line: Use approved black iron pipe with drip leg and sediment trap.
Connect electrical: 120VAC power supply with proper grounding.
Connect thermostat: Use 18-gauge thermostat wire to control board.
Connect ductwork: Secure supply and return air ducts properly.
Connect venting: Install proper Category I vent pipe with upward slope.

WARNING! Gas appliances can be dangerous; installation must be performed by qualified technician. Ensure proper ventilation and combustion air.

First-Time Setup

Power on furnace; follow startup sequence.

Verify gas supply: Ensure gas valve is open and gas pressure is correct.
Check electrical: Confirm 120VAC power and proper thermostat wiring.
Startup sequence: Thermostat calls for heat, inducer motor starts, pressure switch closes, igniter glows, gas valve opens, flame sensor confirms ignition.
Adjust blower speed: Set appropriate CFM for heating application.
Check temperature rise: Verify within specified range (35-65°F).

CAUTION! Never bypass safety controls. Test all safety functions before regular operation.

Specifications

Model: DGAA070BDTA
Input BTU: 70,000 BTU/hr
Output BTU: 56,000 BTU/hr
Efficiency: 80% AFUE
Gas Type: Natural Gas
Blower Motor: Multi-speed ECM
Electrical: 120VAC, 60Hz
Maximum External Static Pressure: 0.5 inches w.c.
Temperature Rise: 35-65°F
Venting: Category I
Dimensions: Standard upflow furnace dimensions

Controls and Settings

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

Control Board: POWER ON/OFF switch, LED status indicator, thermostat terminals, pressure switch connections, gas valve control.

Blower Speed Settings: Adjust blower speed taps for proper airflow. Temperature Rise: Monitor and adjust to stay within 35-65°F range. Gas Pressure: Natural gas manifold pressure 3.5 inches w.c. Limit Controls: High limit switch for overheating protection. Pressure Switches: Prove inducer operation before gas valve opening.

Connecting Thermostat

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

Turn off power to furnace before wiring.
Connect thermostat wires: R (24VAC hot), W (heat), G (fan), C (common).
Secure connections at control board thermostat terminals.
Restore power and test thermostat operation.

Tip: Use proper thermostat wire and ensure tight connections to prevent system faults.

Operation

Normal heating cycle operation sequence.

Thermostat calls for heat sending 24VAC to W terminal.
Inducer motor starts and runs for pre-purge.
Pressure switch closes proving proper venting.
Hot surface igniter glows for approximately 30 seconds.
Gas valve opens allowing gas flow to burners.
Flame sensor confirms ignition within trial-for-ignition period.
Main blower starts after heat exchanger warm-up delay.
When thermostat satisfied, gas valve closes, inducer continues for post-purge.
Blower continues running during fan-off delay.

WARNING! Never operate furnace without proper venting and combustion air. Monitor for unusual noises or odors.

Maintenance

Regular maintenance ensures efficient and safe operation.

Monthly: Check and replace air filter as needed.
Annual: Professional inspection and cleaning.
Clean burners and heat exchanger surfaces.
Check and clean flame sensor.
Verify gas pressure and combustion.
Inspect vent system for obstructions.
Check blower wheel and motor.
Verify safety controls operation.

Care & Cleaning

Turn off power and gas supply before cleaning. Use soft brush and vacuum for heat exchanger and blower assembly.

CAUTION! Do not use water or liquid cleaners. Keep electrical components dry. Never operate with dirty or clogged filter.

Regulatory Information

ANSI Z21.47: Certified for natural gas operation. UL listed. Must be installed in accordance with National Fuel Gas Code and local codes. For technical support, contact Coleman HVAC at 1-888-263-0540 or visit www.colemanac.com. Manufactured for residential use in the United States and Canada.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Furnace won't start	Power/thermostat	Check circuit breaker; verify thermostat setting and wiring.
No heat	Gas supply/ignition	Verify gas valve open; check for ignition failure; inspect flame sensor.
Short cycling	Dirty filter/overheating	Replace air filter; check for restricted airflow; verify proper temperature rise.
Blower won't run	Motor/control	Check blower capacitor; verify control board signals; inspect motor.
Lockout condition	Safety tripped	Reset power; check LED error codes; inspect pressure switches and limits.
Unusual noises	Mechanical issues	Inspect blower wheel; check inducer motor; verify proper clearances.

Reset: Turn power off for 30 seconds then restore to reset control board.

Service: 1-888-263-0540; www.colemanac.com