miller propane furnace manual

The Miller Propane Furnace is a high-efficiency heating system designed for residential and light commercial applications. This furnace features advanced combustion technology, multiple safety controls, variable-speed blower motor, electronic ignition, and compatibility with standard thermostat systems. Below are key sections for safety, features, installation, setup, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Heat exchanger, burner assembly, blower motor, gas valve, control board, pressure switches, flame sensor, and venting system.

Installation Requirements

Professional installation required. Verify local codes and obtain permits.

1. Location: Install in approved locations with proper clearances to combustibles.
2. Gas Supply: Connect to propane gas supply with proper gas line sizing.
3. Electrical: Connect to 120V AC power with proper grounding.
4. Venting: Install PVC vent pipes according to manufacturer specifications.
5. Combustion Air: Provide adequate combustion and ventilation air.

WARNING! Gas furnaces produce carbon monoxide. Proper installation and venting are critical for safety. Use qualified HVAC technician.

First-Time Setup

Initial startup must be performed by qualified technician.

1. Gas pressure adjustment: Set manifold pressure to 10" WC for propane.
2. Venting verification: Check for proper draft and vent pipe installation.
3. Electrical connections: Verify proper voltage and polarity.
4. Thermostat wiring: Connect R, W, G, C terminals as required.
5. System checkout: Perform complete safety and operation testing.

CAUTION! Never operate furnace without proper venting. Test for gas leaks before operation.

Technical Specifications

• Input Capacity: 40,000 - 120,000 BTU/h (model dependent)
• Efficiency: 90%+ AFUE rating
• Gas Type: Propane (LP gas)
• Gas Pressure: 10" WC manifold pressure
• Electrical: 120V AC, 60Hz, 15 amp circuit
• Blower Motor: ECM variable speed
• Airflow: 800 - 2000 CFM
• Venting: 2" or 3" PVC pipe
• Operating Temp Range: -30°F to 120°F ambient
• Warranty: 20-year heat exchanger, 5-year parts

Controls and Settings

Access control board via front panel. Diagnostic LEDs indicate system status.

Control Board: POWER LED (steady green), STATUS LED (flashing codes), HEAT LED (on during heating).

DIP Switch Settings: Heat staging, blower delays, accessory configuration. Gas Valve: Multi-stage operation with pressure regulation. Blower Control: Variable speed settings for different heating stages. Limit Controls: Manual reset high limit switches. Pressure Switches: Prove venting operation before gas valve opens.

Venting and Combustion Air

PVC vent system required. Follow local codes for vent termination.

1. Vent Pipe: Use only approved PVC pipe and fittings.
2. Termination: Minimum clearances from windows, doors, and air intakes.
3. Slope: Horizontal runs must slope upward toward termination.
4. Combustion Air: Provide adequate fresh air for proper combustion.
5. Concentric Vent Kits: Available for simplified installation.

Tip: Always verify proper vent operation with manometer during startup.

Operating Instructions

Normal operation controlled by thermostat.

1. Thermostat Call: Set thermostat above room temperature for heat.
2. Startup Sequence: Inducer motor starts, pressure switches prove, igniter heats, gas valve opens.
3. Flame Proving: Flame sensor confirms ignition, main burner operates.
4. Blower Operation: Blower starts after heat exchanger warms up.
5. Shutdown: Gas valve closes first, inducer continues for purge cycle.
6. Multi-stage Operation: Second stage engages for higher heating demand.
7. Continuous Fan: G terminal from thermostat operates blower without heat.

WARNING! Never block air intakes or exhaust vents. Maintain clearances around furnace.

Maintenance Procedures

Annual maintenance required for safe and efficient operation.

1. Air Filter: Replace or clean filter monthly during heating season.
2. Burner Inspection: Clean burners and check for proper flame pattern.
3. Heat Exchanger: Inspect for cracks or corrosion annually.
4. Blower Assembly: Clean blower wheel and housing annually.
5. Vent System: Inspect for obstructions and proper connections.
6. Drain System: Clear condensate drain lines and trap.
7. Electrical: Check all connections and component operation.

CAUTION! Turn off power and gas supply before performing maintenance.

Safety Features

Multiple safety systems protect against hazardous conditions.

Regulatory Information

UL listed and ANSI Z21.47 compliant. Certified for residential installation. CSA design certified. Installation must comply with National Fuel Gas Code NFPA 54 and local building codes. For technical support, contact Miller Heating & Cooling at 1-800-645-3676 or visit www.millerfurnace.com.

Troubleshooting

LED Error Codes: 1 flash - pressure switch, 2 flashes - limit switch, 3 flashes - flame rollout, 4 flashes - igniter failure, 5 flashes - flame sense

Service: 1-800-645-3676; www.millerfurnace.com