Atwood Hydro Flame Furnace Repair Manual

The Atwood Hydro Flame Furnace is a high-efficiency heating system designed for RV and mobile applications, featuring electronic ignition, multiple heat settings, safety shut-off systems, and easy maintenance access. Below are key sections for safety procedures, technical specifications, troubleshooting, repair instructions, and maintenance guidelines.

Safety Precautions

Critical safety measures must be followed during all repair and maintenance procedures.

Model Identification

Locate model number on furnace label for proper parts identification and service procedures.

1. Model number format: HFxxxx (e.g., HF32121)
2. Serial number location: Right side of furnace housing
3. Manufacturing date: Encoded in serial number
4. BTU rating: Varies by model (16,000-40,000 BTU)

WARNING! Use only genuine Atwood replacement parts for your specific model.

Technical Specifications

• Fuel Type: Propane/LP Gas
• Input Range: 16,000-40,000 BTU/hr
• Voltage: 12V DC
• Current Draw: 3.5-10.5 amps (depending on model)
• Ignition System: Direct spark electronic ignition
• Airflow: 100-200 CFM (blower dependent)
• Dimensions: Varies by model (typically 14"L x 10"W x 9"H)
• Weight: 8-15 lbs

System Components

Major components: Control module, blower motor, sail switch, igniter, gas valve, thermostat, limit switches.

Control Module: Main brain of furnace; monitors all safety circuits and ignition sequence. Blower Motor: Provides combustion air and distributes heated air. Sail Switch: Ensures proper airflow before gas valve opens. Igniter: Creates spark for gas ignition. Gas Valve: Regulates gas flow to burner assembly.

Troubleshooting Guide

Diagnostic procedures for common furnace problems.

1. Check power supply: Verify 12V DC to furnace
2. Inspect thermostat: Set to heat mode, temperature above ambient
3. Test sail switch: Should close when blower reaches proper speed
4. Verify gas supply: Check propane tank level and valve position
5. Examine control module: Look for error codes or LED indicators

Tip: Always start with simplest solutions before complex diagnostics.

Common Repairs

Step-by-step repair procedures for frequent issues.

1. Blower motor replacement: Disconnect power, remove housing, replace motor
2. Igniter cleaning: Remove igniter, clean with emery cloth, reinstall
3. Sail switch adjustment: Test with multimeter, adjust or replace as needed
4. Gas valve replacement: Shut off gas, depressurize line, replace valve
5. Control module replacement: Note wiring positions, install new module
6. Thermostat wiring: Check for loose connections or damaged wires

WARNING! Always test furnace operation completely after any repair.

Parts Replacement

Genuine Atwood replacement parts and installation procedures.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

Monthly: Check air intake and exhaust for obstructions. Seasonal: Clean burner assembly and inspect igniter. Annual: Complete system inspection, verify all safety controls, check gas connections.

CAUTION! Only qualified technicians should perform complex maintenance procedures.

Testing Procedures

Comprehensive testing after repairs or maintenance.

1. Visual inspection: Check all components for proper installation
2. Gas leak test: Apply soap solution to all gas connections
3. Ignition test: Verify proper spark and flame establishment
4. Safety controls: Test limit switches and sail switch operation
5. Performance test: Run furnace through complete heating cycle

Warranty Information

Atwood Hydro Flame furnaces come with limited warranties covering materials and workmanship.

• Residential Use: 2-year limited warranty
• Commercial Use: 1-year limited warranty
• Parts Only: 90-day warranty on replacement parts
• Labor: Not covered under standard warranty

For warranty claims, contact authorized service centers with proof of purchase.

Contact Support

Emergency: For gas leaks or fire hazards, evacuate area and call emergency services immediately.

Documentation: Complete service manuals available at www.atwoodsupport.com