Atwood Hydro Flame 8500-IV Series Furnace Manual

The Atwood Hydro Flame 8500-IV Series is a high-efficiency RV furnace designed for reliable heating performance in recreational vehicles. This forced-air furnace features electronic ignition, multiple BTU output options, 12V DC operation, built-in safety controls, and easy installation/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 RV Systems 7. Operating Procedures 8. Maintenance Schedule 9. Care & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Combustion chamber, blower assembly, electronic control board, sail switch, limit switch, gas valve, exhaust system.

FeatureDescription
BTU OutputMultiple settings from 8,500 to 16,000 BTU
Ignition SystemElectronic spark ignition
Power Source12V DC RV electrical system
Fuel TypePropane/LP gas
Air FlowForced-air blower system
Safety ControlsLimit switch, sail switch, overheat protection
Exhaust SystemSealed combustion with exterior venting
Thermostat ControlCompatible with standard RV thermostats
MountingFloor or wall mount options
Access PanelRemovable for service access

Installation

Unpack and inspect all components. Ensure proper ventilation clearance.

  1. Select mounting location: Choose area with adequate combustion air and exhaust clearance.
  2. Cut opening: Follow template for exhaust/intake vents and mounting holes.
  3. Connect gas line: Use approved LP gas fittings and leak test all connections.
  4. Wire electrical: Connect 12V DC power following wiring diagram.
  5. Install thermostat: Connect to control wires for temperature regulation.
  6. Secure furnace: Mount firmly using provided hardware.

WARNING! Installation must comply with RVIA standards and local codes. Gas connections require professional installation.

First-Time Setup

Complete installation checks before initial operation.

  1. Gas system check: Verify all connections are tight and leak-free.
  2. Electrical check: Confirm proper 12V DC polarity and voltage.
  3. Ventilation check: Ensure exhaust and intake are unobstructed.
  4. Initial startup: Follow lighting procedure in operation section.
  5. Test safety controls: Verify limit switch and sail switch function.

CAUTION! Never operate without proper ventilation. Test for gas leaks with soap solution.

Specifications

Controls and Settings

Operation controlled via RV thermostat. Internal safety controls include limit switch, sail switch, and ignition control module.

Thermostat Settings: HEAT/COOL/OFF modes, temperature setpoint, fan control (AUTO/ON).

Internal Controls: Electronic ignition module, gas valve control, blower motor relay, safety limit switch, sail switch (proves air flow).

LED Indicators: Green (normal operation), Red (lockout/fault condition), Yellow (ignition sequence).

Connecting to RV Systems

Integrates with RV propane system, 12V electrical, and thermostat control.

  1. Gas connection: 3/8" flare fitting to RV propane system.
  2. Electrical: 12V DC positive and negative connections.
  3. Thermostat: 2-4 wire connection depending on thermostat type.
  4. Venting: 3-4" exhaust and intake pipes to exterior.

Tip: Use thread sealant rated for LP gas on all gas connections.

Operating Procedures

Normal operation through RV thermostat.

  1. Set thermostat to desired temperature and HEAT mode.
  2. Furnace initiates: Blower starts for pre-purge cycle.
  3. Ignition sequence: Spark igniter activates, gas valve opens.
  4. Flame detection: If flame established, continues operation.
  5. Safety monitoring: Continuous monitoring of flame, temperature, and air flow.
  6. Shutdown: Thermostat satisfied - gas valve closes, blower continues for post-purge.

WARNING! Never bypass safety controls. If furnace locks out, wait 5 minutes before resetting.

Maintenance Schedule

Regular maintenance ensures optimal performance and safety.

IntervalMaintenance Task
MonthlyCheck vent system for obstructions
SeasonalInspect burner and combustion chamber
AnnualProfessional inspection and cleaning
Every 2 yearsReplace sail switch if worn
As neededClean air filter and blower wheel

Care & Cleaning

Disconnect power and gas before servicing.

  1. Exterior: Wipe with damp cloth, mild detergent if needed.
  2. Vent system: Inspect for nests, debris, or blockages.
  3. Burner assembly: Clean with soft brush, compressed air.
  4. Blower wheel: Remove dust and debris buildup.
  5. Air filter: Clean or replace as needed.

CAUTION! Never use water or liquid cleaners on electrical components or burner assembly.

Regulatory Information

Certified to ANSI Z21.44/CSA 2.3 for recreational vehicle heaters. Complies with RVIA standards. Manufactured by Atwood Mobile Products. For technical support, contact 1-800-888-3370 or visit www.atwoodmobile.com. This product must be installed by qualified personnel in accordance with all local codes and regulations.

Troubleshooting

SymptomPossible CauseCorrective Action
No ignitionGas supply, spark gapCheck propane supply; verify spark electrode gap and condition.
Blower runs, no heatGas valve, ignitionCheck gas valve operation; verify spark ignition sequence.
Short cyclingDirty filter, limit switchClean/replace air filter; check limit switch operation.
Lockout conditionSafety shutdownWait 5 minutes; reset thermostat; check error codes.
Poor air flowBlocked vents, blowerClear obstructions; check blower wheel and motor.
Gas odorLeaks, combustionImmediately shut off gas; check for leaks; verify proper combustion.

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

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

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