Dettson Furnace Manual

The Dettson Furnace is a high-efficiency residential heating system designed for reliable performance and energy savings. This manual covers installation, operation, maintenance, and troubleshooting for various Dettson furnace models. Below are key sections for safety, features, installation, setup, operation, and maintenance procedures.

Features at a Glance

Key components: High-efficiency heat exchanger, electronic ignition system, variable-speed blower motor, multi-speed settings, diagnostic LED system, and built-in safety controls.

Installation Requirements

Proper installation is critical for safe and efficient operation. Follow all local codes and manufacturer guidelines.

1. Location: Install in dry, well-ventilated area with adequate clearance for service access.
2. Venting: Use approved PVC piping for combustion air and exhaust venting.
3. Gas Connection: Use approved gas pipe and fittings; pressure test before operation.
4. Electrical: Connect to dedicated 120V circuit with proper grounding.
5. Ductwork: Ensure proper sizing and sealing of supply and return ducts.

WARNING! Installation must be performed by qualified HVAC technician. Improper installation can cause fire, explosion, or carbon monoxide poisoning.

Initial Setup & Startup

Follow these steps for proper furnace commissioning and initial operation.

1. Verify all connections: Gas, electrical, and venting properly installed and secured.
2. Check gas pressure: Adjust manifold pressure to specifications on rating plate.
3. Set blower speeds: Configure cooling and heating speeds according to duct design.
4. Test safety controls: Verify limit switches, pressure switches, and flame sensor operation.
5. Program thermostat: Set heating setpoints, fan operation, and system mode.

CAUTION! Never bypass safety controls. Always test carbon monoxide detectors after installation.

Technical Specifications

• Heating Capacity: 40,000 to 120,000 BTU/H depending on model
• Efficiency Rating: 80% to 96% AFUE
• Gas Type: Natural gas or propane (conversion kit required)
• Electrical: 120V AC, 60Hz, 5-15 amp circuit
• Blower Motor: ECM variable speed, 3/4 to 1-1/2 HP
• Air Flow: 800 to 2000 CFM depending on model
• Static Pressure: 0.1 to 0.8 inches water column
• Venting: 2-inch to 3-inch PVC pipe
• Dimensions: Varies by model (check specific model data)
• Weight: 80 to 150 pounds depending on model

Controls and Operation

Furnace operation is controlled by integrated control board and external thermostat.

Control Board: POWER switch, diagnostic LED, mode selection, blower control, safety circuit monitoring.

Thermostat Settings: HEAT/COOL/OFF mode, temperature setpoint, fan AUTO/ON, system programming. LED Codes: Green - normal operation, Red flash codes - error conditions (refer to troubleshooting chart). Blower Operation: AUTO - cycles with heat call, ON - continuous operation. Gas Valve: Modulating or multi-stage for precise temperature control.

Maintenance Procedures

Regular maintenance ensures optimal performance and extends furnace lifespan.

1. Monthly: Check and replace air filter if dirty.
2. Seasonal: Inspect burners, heat exchanger, and venting system.
3. Annual: Professional inspection and cleaning of all components.
4. As needed: Clean blower wheel and housing, check electrical connections.

Tip: Keep area around furnace clean and free of combustible materials.

Thermostat Configuration

Compatible with standard 24V thermostats and programmable models.

1. Wiring: Connect R (power), W (heat), G (fan), C (common) terminals.
2. Programming: Set heating schedule, temperature setbacks, fan operation.
3. Calibration: Verify temperature accuracy and system response.
4. Advanced: Configure staging, fan delays, and system timing if applicable.

WARNING! Turn off power before wiring thermostat. Follow manufacturer wiring diagram.

Safety Features

Multiple safety systems protect against hazardous conditions. Flame Rollout Switch: Detects improper burner operation. High Limit Switch: Prevents overheating. Pressure Switch: Ensures proper venting. Flame Sensor: Confirms burner ignition. Gas Valve: Automatic shutoff if ignition fails.

Cleaning & Service

Regular cleaning maintains efficiency and prevents breakdowns.

CAUTION! Turn off power and gas supply before servicing. Use approved cleaning methods only.

Warranty Information

Dettson furnaces include limited warranties: Heat exchanger - 20 years, Parts - 5 years, Labor - 1 year. Registration required within 60 days of installation. Warranty void if installed by unqualified personnel or improper maintenance. For claims, contact Dettson customer service with model and serial numbers.

Troubleshooting Guide

Reset: Power cycle furnace or press reset button if equipped.

Service: 1-800-DETTSON; www.dettson.com