Atwood Furnace 8940 Manual

The Atwood Furnace 8940 is a high-efficiency RV furnace designed for reliable heating in recreational vehicles. This forced-air furnace features electronic ignition, multiple heat settings, safety shut-off systems, and easy maintenance access. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.

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

Features at a Glance

Key components: Electronic ignition system, forced-air blower, heat exchanger, thermostat control, safety shut-off valve, exterior vent.

Feature	Description
Electronic Ignition	Automatic spark ignition for reliable startup
Forced-Air Blower	Distributes heated air throughout RV interior
Heat Exchanger	Stainless steel construction for efficient heat transfer
Thermostat Control	Adjustable temperature settings
Safety Shut-off	Automatic gas shut-off if flame is not detected
Exterior Vent	Combustion air intake and exhaust outlet
Multiple Heat Settings	Low, Medium, High heat output options
LED Status Indicator	Shows operational status and error codes
Easy Access Panel	Removable front panel for maintenance
Compact Design	Fits standard RV furnace compartments

Installation

Unpack and inspect contents. Ensure proper ventilation clearance.

Mount furnace: Secure in designated RV compartment with provided brackets.
Connect ductwork: Attach heating ducts to furnace outlet.
Gas line connection: Use approved gas line fittings; check for leaks.
Electrical connection: Connect to 12V DC RV power system.
Vent installation: Ensure exterior vent is clear of obstructions.

WARNING! Gas appliances require professional installation. Ensure all connections are secure and leak-free.

First-Time Setup

Power on furnace; follow startup procedure.

Check gas supply: Ensure propane tank has adequate fuel.
Power connection: Verify 12V DC power is available.
Thermostat setting: Set to desired temperature.
Initial startup: System will perform self-check and ignition sequence.
Test operation: Verify heat output and blower function.

CAUTION! Ensure proper ventilation; test for carbon monoxide after installation.

Specifications

Model: Atwood 8940
Fuel Type: Propane/LP Gas
BTU Output: 30,000 BTU
Power Requirement: 12V DC
Airflow: 120 CFM maximum
Dimensions: 15" x 10" x 7"
Weight: 12 lbs
Ignition: Electronic spark
Safety Features: Flame failure detection, overheat protection
Warranty: 2 years limited

Controls and Settings

Access controls via thermostat or furnace control board.

Thermostat: Temperature setting, fan control, system on/off.

Furnace Controls: Power switch, reset button, LED status indicator.

Heat Settings: Low (15,000 BTU), Medium (22,500 BTU), High (30,000 BTU). Fan Control: Automatic or manual operation. Safety Settings: Automatic shut-off, flame sensor monitoring.

Connecting to Power

12V DC connection required for operation.

Turn off all power before connecting.
Connect positive and negative wires to appropriate terminals.
Ensure proper fuse rating (15A recommended).
Verify ground connection.

Tip: Use marine-grade wiring for corrosion resistance in RV applications.

Operation

Standard operating procedure for heating.

Set thermostat to desired temperature.
System will automatically ignite when heat is needed.
Blower will start once heat exchanger reaches temperature.
Monitor LED indicator for normal operation (steady green).
To shut down: Turn thermostat to off position.

WARNING! Never operate with blocked vents. Ensure adequate combustion air.

Maintenance

Regular maintenance ensures optimal performance and safety.

Monthly: Check exterior vent for obstructions.
Seasonal: Inspect burner assembly and heat exchanger.
Annual: Professional inspection recommended.
As needed: Clean air intake filter.

Care & Cleaning

Turn off power and gas supply before cleaning.

Use soft brush for burner cleaning. Compressed air for dust removal. Mild detergent for exterior surfaces.

CAUTION! Do not use water or liquid cleaners on electrical components.

Regulatory Information

CSA certified for RV use. Complies with ANSI Z21.44 standards. Manufactured to meet RV industry requirements. For support, contact Atwood Customer Service at 1-800-555-HEAT or visit www.atwoodmobile.com.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Furnace won't start	Power/gas supply	Check 12V power; verify gas valve open; check thermostat setting.
No heat output	Ignition failure	Listen for spark; check gas supply; reset system.
Blower not working	Motor/electrical	Check fuse; verify power to blower motor; listen for motor hum.
LED flashing red	Error condition	Consult error code chart; reset system; check flame sensor.
Unusual odors	Dust/burnoff	Normal during first use; persistent odors indicate professional service needed.

Reset: Turn thermostat off for 30 seconds, then back on.

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