Mellen Furnace Manual

The Mellen Furnace is a high-efficiency residential heating system designed for reliable performance and energy savings. This furnace features advanced combustion technology, multiple heat stages, variable-speed blower motor, smart thermostat compatibility, safety shut-off systems, and easy maintenance access. Rated for natural gas or propane operation with AFUE ratings up to 98%. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: Heat exchanger, burners, blower assembly, gas valve, control board, filter compartment, flue outlet, drain connections.

Feature	Description
Heat exchanger	Stainless steel primary and secondary heat exchangers
Burner assembly	Multi-port inshot burners for efficient combustion
Blower motor	Variable-speed ECM motor for quiet operation
Control board	Microprocessor-based with diagnostic LEDs
Filter compartment	Standard 1-inch or 4-inch media filter compatible
Gas valve	Multi-stage gas control with pressure regulation
Flue outlet	PVC venting compatible for sidewall or roof termination
Drain connections	Condensate drain ports with trap assembly
Safety switches	Pressure switch, rollout switch, high-limit switch
Ignition system	Hot surface igniter with flame sensor

Installation

Unpack and inspect all components. Ensure proper clearances and venting requirements.

1. Position furnace: Place on level surface in approved location with proper clearances.
2. Connect gas line: Use black iron pipe with proper thread sealant; pressure test required.
3. Install venting: Use approved PVC pipe for intake and exhaust; maintain proper slope.
4. Connect electrical: 120V AC power supply with dedicated circuit; proper grounding.
5. Connect thermostat: Use 18-gauge thermostat wire; follow wiring diagram.
6. Install condensate drain: Route to floor drain with proper trap and slope.

WARNING! Gas furnaces produce carbon monoxide; proper venting is critical. Installation must comply with local codes.

First-Time Setup

Power on furnace; follow startup sequence and verify proper operation.

1. Verify gas supply: Ensure gas valve is open; check for leaks with soap solution.
2. Set thermostat: Install batteries; configure heating mode and temperature settings.
3. Test operation: Set thermostat above room temperature; verify ignition sequence.
4. Check airflow: Verify proper airflow from all registers; adjust dampers if needed.
5. Monitor operation: Observe complete heating cycle; check for proper shutdown.

CAUTION! Never bypass safety controls. If furnace fails to start properly, shut off power and gas immediately.

Specifications

• Heating Capacity: 40,000 to 120,000 BTU/h models available
• AFUE Rating: Up to 98% efficiency
• Fuel Type: Natural gas or propane (conversion kit required)
• Electrical: 120V AC, 60Hz, 5-15 Amp circuit
• Blower Motor: Variable-speed ECM, ½ to ¾ HP
• Stages: Single-stage, two-stage, or modulating models
• Venting: PVC, CPVC, or ABS 2-inch to 3-inch diameter
• Sound Rating: As low as 65 dBA
• Warranty: 20-year heat exchanger, 10-year parts

Controls and Settings

Access control board via front panel. LED status lights indicate system operation and error codes.

Thermostat Controls: HEAT/COOL/OFF mode, FAN AUTO/ON, temperature setpoints, program schedules.

Furnace Settings: Blower speed adjustments, gas pressure settings, timing delays, diagnostic mode. Control Board: Status LED flash codes, reset button, dip switch settings for staging and timing. Safety Systems: Pressure switch monitoring, flame rollout protection, high-limit temperature control, igniter lockout.

Connecting Thermostat

Compatible with most 24V thermostats including programmable and smart models.

1. Turn off furnace power at circuit breaker or disconnect switch.
2. Remove old thermostat and note wire connections.
3. Connect wires to new thermostat: R (power), W (heat), G (fan), C (common), Y (cooling if applicable).
4. Mount thermostat on wall and restore power.
5. Configure thermostat settings for furnace operation.

Tip: Use thermostat compatible with your furnace staging (single-stage, two-stage, modulating).

Operating Modes

Multiple operating modes for efficiency and comfort control.

1. Heating Mode: Primary operation; maintains set temperature with staged heating.
2. Fan Only: Circulates air without heating; improves air filtration and distribution.
3. Standby Mode: System ready but not actively heating; maintains system monitoring.
4. Diagnostic Mode: Service mode for troubleshooting and system testing.
5. Smart Recovery: Learns heating cycle times to reach set temperature at scheduled times.
6. Humidity Control: Works with humidifier to maintain optimal indoor humidity levels.

WARNING! Do not operate furnace without proper venting and combustion air. Ensure filters are clean.

Maintenance Features

Self-diagnostic system with LED error codes. Easy access panels for routine maintenance.

Filter Replacement: Slide-out filter rack; recommended every 1-3 months. Annual Maintenance: Professional inspection recommended before each heating season. Diagnostic Codes: LED flash patterns indicate specific issues for troubleshooting.

Care & Cleaning

Regular maintenance ensures optimal performance and longevity.

1. Monthly: Check and replace air filter as needed.
2. Seasonal: Inspect vent pipes for obstructions; clean flame sensor.
3. Annual: Professional cleaning of burners, heat exchanger, and blower assembly.
4. As needed: Clean condensate drain line and trap.

CAUTION! Always turn off power and gas supply before performing any maintenance. Use only approved replacement parts.

Regulatory Information

UL certified for safety standards. ANSI Z21.47 compliant for gas-fired central furnaces. Meets DOE energy efficiency requirements. CSA International certified for Canadian standards. For technical support, visit www.mellenfurnace.com or contact 1-800-555-HEAT. Installation must comply with National Fuel Gas Code (NFPA 54) and local building codes.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Furnace won't start	Power, thermostat, safety lockout	Check circuit breaker; verify thermostat settings; reset furnace.
No heat	Gas supply, igniter, flame sensor	Verify gas valve open; check for spark/flame; clean flame sensor.
Short cycling	Dirty filter, airflow, overheating	Replace filter; check registers; verify proper venting.
Blower not working	Motor, capacitor, control board	Check power to motor; test capacitor; verify control signals.
Unusual noises	Motor bearings, ductwork, heat exchanger	Lubricate motor if applicable; check for loose panels; inspect heat exchanger.

Reset: Power cycle furnace at disconnect switch or circuit breaker.

Service: 1-800-555-HEAT; www.mellenfurnace.com