atwood hydro flame furnace manual 7900 11

The Atwood Hydro Flame Furnace Model 7900-11 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 covering safety precautions, installation, operation, maintenance, troubleshooting, and technical specifications.

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

Features at a Glance

Key components: Electronic ignition system, forced-air blower, heat exchanger, gas valve, thermostat control, exhaust system, and safety shut-off devices.

Feature	Description
Electronic Ignition	Pilotless ignition for reliable startup
Forced-Air Blower	Distributes heated air throughout RV
Heat Exchanger	Stainless steel construction for efficiency
Gas Valve	Regulates propane flow to burner
Thermostat Control	Adjustable temperature settings
Safety Shut-off	Automatic shut-off if flame fails
Exhaust System	Vents combustion gases safely outside
Multiple Heat Settings	High/Low heat options
Easy Access Panel	Quick maintenance access
Compact Design	Fits standard RV furnace compartments

Installation

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

Mount furnace: Secure in designated RV compartment with proper clearances.
Connect gas line: Use approved propane gas line with proper fittings.
Electrical connection: Connect to 12V DC RV power system.
Vent installation: Install exterior vent cap and interior air return.
Test operation: Verify proper ignition and airflow.

WARNING! Gas appliances require professional installation. Ensure all connections are leak-tested before operation.

First-Time Setup

Initial startup and system verification.

Gas system check: Ensure propane tank is filled and valves are open.
Power connection: Verify 12V DC power is available.
Thermostat setting: Set thermostat to desired temperature.
Initial ignition: System will attempt ignition automatically.
Airflow verification: Check that warm air is circulating properly.

CAUTION! Never operate furnace without proper ventilation. Test carbon monoxide detector.

Specifications

Model: Hydro Flame 7900-11
Fuel Type: Liquid Propane (LP) Gas
BTU Output: 16,000-30,000 BTU (depending on setting)
Power Requirement: 12V DC
Ignition: Electronic direct spark
Airflow: Forced air with variable speed blower
Dimensions: Standard RV furnace size
Weight: Approximately 15 lbs
Vent Requirements: Outside venting mandatory
Operating Temp Range: -40°F to 120°F

Controls and Settings

Primary control via RV thermostat. Manual override available at furnace unit.

Thermostat Controls: Temperature setting, fan control (auto/on), system on/off.

Furnace Controls: Manual reset button, gas valve control, blower speed adjustment.

Operating Modes: High heat, Low heat, Fan only. Safety Features: Flame rollout switch, overheat protection, pressure switch, sail switch.

Connecting to Power & Gas

Proper connection to RV electrical and propane systems.

Turn off all power and gas before connecting.
Electrical: Connect to 12V DC system with proper fuse protection.
Gas line: Use approved flexible gas line with leak-tested connections.
Grounding: Ensure proper electrical grounding.
Final check: Verify all connections are secure and leak-free.

Tip: Use gas leak detector solution to test all gas connections.

Operating Procedures

Normal furnace operation and cycling.

Set thermostat: Adjust to desired temperature setting.
System startup: Blower starts first, then ignition sequence begins.
Flame verification: System confirms flame presence.
Heating cycle: Burner operates until thermostat setting is reached.
Post-purge: Blower continues briefly after burner shuts off.
Shutdown: Turn thermostat to off position when not needed.

WARNING! Never block air intake or exhaust vents. Ensure proper ventilation at all times.

Safety Features

Multiple safety systems protect against hazardous conditions.

Flame Rollout Switch: Shuts off gas if flame escapes burner area. Overheat Protection: Prevents furnace from overheating. Pressure Switch: Ensures proper venting before ignition. Sail Switch: Confirms airflow before gas valve opens. Automatic Shut-off: Activates if ignition fails after multiple attempts.

Maintenance & Cleaning

Regular maintenance ensures optimal performance and safety.

Annual inspection: Check all components before heating season.
Burner cleaning: Remove and clean burner assembly annually.
Blower maintenance: Clean blower wheel and motor.
Vent system: Inspect and clean exhaust vent and intake.
Filter replacement: Replace or clean air filters regularly.

CAUTION! Always disconnect power and gas before performing maintenance.

Regulatory Information

CSA/UL approved for RV use. Complies with ANSI Z21.44 standards for gas-fired recreational vehicle heating systems. Manufactured by Atwood Mobile Products. For technical support, contact Atwood Customer Service at 1-800-888-3378 or visit www.atwoodmobile.com.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Furnace won't start	Power/gas supply	Check 12V power; verify propane supply; check thermostat setting.
Blower runs but no heat	Ignition failure	Check gas valve; inspect igniter; verify flame sensor.
Short cycling	Overheating/airflow	Clean air filters; check vents for obstruction; verify proper clearance.
Unusual noises	Blower/motor issues	Inspect blower wheel; check motor bearings; clean debris.
Gas odor	Leaks/vent issues	Immediately shut off gas; check for leaks; verify proper venting.

Reset Procedure: Turn thermostat off, wait 5 minutes, then restart.

Service: 1-800-888-3378; www.atwoodmobile.com