Atwood Hydro Flame 8900-111 RV Furnace Manual

The Atwood Hydro Flame 8900-111 is a high-efficiency RV furnace designed for recreational vehicles, featuring electronic ignition, variable-speed blower, and multiple safety systems. This forced-air furnace operates on propane/LP gas and provides reliable heating for RV interiors. Below are key sections covering safety, features, installation, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Operation 6. Gas Connection 7. Electrical Wiring 8. Maintenance Procedures 9. Safety Features 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Electronic ignition system, variable-speed blower motor, flame sensor, sail switch, limit switch, and thermal fuse.

Feature	Description
Electronic Ignition	No standing pilot light; energy efficient ignition
Variable-Speed Blower	Adjustable airflow for optimal heating
Flame Sensor	Monitors burner flame for safety shutdown
Sail Switch	Ensures proper airflow before ignition
Limit Switch	Prevents overheating by monitoring temperature
Thermal Fuse	Additional safety device for over-temperature protection
Propane Operation	Designed for LP gas fuel source
Wall Thermostat	Standard RV thermostat compatibility
Forced Air System	Distributes heat throughout RV interior
Compact Design	Fits standard RV furnace compartments

Installation

Proper installation is critical for safe operation. Follow all local codes and regulations.

Select location: Choose well-ventilated area with proper clearance from combustible materials.
Mount furnace: Secure in designated RV compartment using provided brackets.
Connect ductwork: Attach heat distribution ducts to furnace outlet.
Install exterior vent: Ensure proper sealing and weatherproofing.
Connect gas line: Use approved LP gas fittings and pipe thread sealant.
Wire electrical: Connect to 12V DC RV power system.

WARNING! Installation must be performed by qualified technician. Gas leaks can cause explosion or fire.

First-Time Setup

Initial startup and system verification procedures.

Gas system check: Verify all gas connections are tight and leak-free.
Electrical connection: Ensure proper 12V DC power supply.
Ventilation check: Confirm exterior vent is clear and unobstructed.
Thermostat setup: Install and calibrate RV thermostat.
Test ignition: Initiate heating cycle to verify proper operation.
Safety system verification: Confirm all safety switches function correctly.

CAUTION! Always test for gas leaks with soap solution before initial operation.

Specifications

Model: Hydro Flame 8900-111
Fuel Type: Propane/LP Gas
BTU Output: 25,000-30,000 BTU/hr (depending on model variant)
Electrical: 12V DC operation
Ignition: Electronic spark ignition
Blower Type: Variable-speed centrifugal
Dimensions: Compact design for RV installation
Vent Requirements: Direct vent system
Gas Pressure: 11" water column
Weight: Approximately 15-20 lbs

Controls and Operation

Operation via standard RV thermostat. No manual controls on furnace unit.

Thermostat Operation: Set desired temperature; furnace cycles automatically to maintain setting.

Startup Sequence: Thermostat call for heat → Blower starts → Sail switch confirms airflow → Ignition spark → Gas valve opens → Flame sensor confirms ignition → Heating cycle begins.

Shutdown Sequence: Thermostat satisfied → Gas valve closes → Blower continues for cool-down → System off.

Gas Connection

LP gas system requirements and connection procedures.

Use only approved LP gas fittings and black iron pipe.
Apply pipe thread sealant rated for LP gas service.
Connect to RV propane system with proper shutoff valve.
Test all connections with leak detection solution.
Verify gas pressure at furnace inlet (11" WC required).

Tip: Always turn off propane at main tank when not in use or during maintenance.

Electrical Wiring

12V DC electrical connection requirements.

Connect to RV 12V DC power system with proper fuse protection.
Use minimum 14-gauge wire for power connections.
Ensure proper grounding to RV chassis.
Connect thermostat wires according to RV wiring diagram.
Verify polarity; reverse polarity can damage control board.

WARNING! Disconnect battery power before performing any electrical work.

Maintenance Procedures

Regular maintenance ensures optimal performance and safety.

Annual inspection: Check all components before heating season.
Clean burner assembly: Remove debris and inspect flame pattern.
Check sail switch: Ensure free movement and proper operation.
Inspect vent system: Clear any obstructions from exterior vent.
Test safety devices: Verify limit switch and thermal fuse function.
Lubricate blower motor: If required by specific model.

CAUTION! Always disconnect power and gas supply before maintenance.

Safety Features

Multiple safety systems protect against hazardous conditions.

Safety Device	Function
Flame Sensor	Shuts off gas if flame not detected
Sail Switch	Prevents ignition without proper airflow
Limit Switch	Shuts down system if overheated
Thermal Fuse	One-time safety device for extreme over-temperature
Gas Valve	Automatic shutoff when system off

Regulatory Information

Complies with ANSI Z21.44 standards for recreational vehicle heaters. CSA certified for US and Canadian markets. Manufactured by Atwood Mobile Products. For technical support, contact Atwood Customer Service at 1-800-888-3370 or visit www.atwoodmobile.com.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No ignition	Gas supply, spark electrode	Check propane supply; inspect spark electrode and wire
Blower runs but no heat	Sail switch, gas valve	Test sail switch operation; check gas valve function
Short cycling	Limit switch, airflow	Check limit switch; ensure proper duct airflow
No blower operation	Power, motor, thermostat	Verify 12V power; test blower motor; check thermostat
Gas odor	Leaks, improper combustion	Immediately shut off gas; check for leaks; verify venting

Reset: Turn thermostat off for 5 minutes, then back on.

Service: 1-800-888-3370; www.atwoodmobile.com