Gaffers & Sattler U100 Furnace Manual

The Gaffers & Sattler U100 Furnace is a high-efficiency residential heating unit with advanced combustion technology, electronic ignition system, variable-speed blower motor, and integrated smart thermostat compatibility. Designed for natural gas operation with 95% AFUE rating, this furnace features multiple heat stages, quiet operation, durable heat exchanger construction, and comprehensive safety controls. Below are key sections for safety, features, installation, setup, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Stainless steel heat exchanger, electronic control board, inducer motor, blower assembly, gas valve, flame sensor, pressure switches, and diagnostic LED.

Installation Requirements

Professional installation recommended. Verify local codes and obtain permits.

1. Location: Install in dry, clean area with adequate combustion air and service clearance.
2. Gas Connection: Use black iron pipe with proper thread sealant; pressure test required.
3. Electrical: 120VAC dedicated circuit; proper grounding essential.
4. Venting: PVC vent pipes per manufacturer specifications; maintain proper slope.
5. Ductwork: Size appropriately for CFM requirements; seal all connections.

WARNING! Gas appliances can be dangerous if improperly installed. Only qualified technicians should perform installation.

First-Time Setup

Complete installation verification before initial startup.

1. Gas pressure adjustment: Set manifold pressure to 3.5" WC for natural gas.
2. Blower speed settings: Adjust dip switches for proper airflow (CFM).
3. Thermostat configuration: Connect compatible thermostat; set heating mode.
4. System checkout: Verify all safety controls function properly.
5. Combustion analysis: Measure flue gases for proper CO2 and O2 levels.

CAUTION! Never bypass safety controls. Test all safety functions before placing in service.

Technical Specifications

• Model: U100 Series
• Fuel Type: Natural Gas
• Input Capacity: 60,000 - 120,000 BTU/H (depending on model)
• AFUE Rating: 95%
• Electrical: 120VAC, 60Hz, 5 Amps
• Gas Connection: 1/2" NPT
• Vent Size: 2" or 3" PVC
• Static Pressure: 0.1" to 0.8" WC
• Sound Rating: < 65 dBA
• Dimensions: 44" H x 21" W x 26" D
• Warranty: 20-year heat exchanger, 5-year parts

Controls and Settings

Integrated control board with dip switch settings and status LED. Access panel must be properly installed for unit operation.

Control Board Features: Power indicator, status LED, diagnostic code display, dip switches for blower speed and timing.

Operating Modes: HEAT, OFF, FAN ON. Blower Settings: Adjustable delay-on and delay-off timers. Temperature Control: Compatible with single-stage and multi-stage thermostats. Diagnostic Codes: Flashing LED indicates specific error conditions for troubleshooting.

Venting and Ductwork

Direct vent system using PVC pipe for intake and exhaust.

1. Vent Pipe: Use only manufacturer-approved PVC materials.
2. Clearances: Maintain required clearances to combustible materials.
3. Terminations: Locate vent terminals per local code requirements.
4. Duct Sizing: Calculate proper duct size based on CFM requirements.
5. Airflow: Verify static pressure within acceptable range.

Tip: Ensure vent pipes are properly supported and sealed to prevent condensation issues.

Operating Procedures

Normal operation controlled by wall thermostat.

1. Thermostat Setting: Set to desired temperature in HEAT mode.
2. Startup Sequence: Inducer motor starts, pressure switch verifies, igniter heats, gas valve opens.
3. Flame Verification: Flame sensor confirms ignition, main burner operates.
4. Blower Operation: Blower starts after heat exchanger warm-up delay.
5. Shutdown: Gas valve closes first, inducer continues for post-purge, blower runs cool-down cycle.

WARNING! Never operate furnace without access panels properly installed. Keep combustible materials away from furnace.

Maintenance Schedule

Regular maintenance essential for safe and efficient operation.

Safety Features

Multiple safety systems protect against hazardous conditions.

• Flame Rollout Switches: Detect improper burner flames
• High Limit Switches: Prevent overheating
• Pressure Switches: Verify proper venting operation
• Flame Sensor: Ensures gas valve only operates with flame
• Door Safety Switch: Prevents operation with panels removed
• Ignition Lockout: Prevents repeated ignition attempts

CAUTION! If safety device trips repeatedly, discontinue use and contact qualified technician.

Regulatory Information

ANSI Z21.47/CSA 2.3: Certified for natural gas operation. UL Listed: Electrical components meet safety standards. Installation must comply with National Fuel Gas Code (NFPA 54) and local building codes. For technical support, contact Gaffers & Sattler at 1-800-555-HEAT or visit www.gaffers-sattler.com.

Troubleshooting Guide

Reset Procedure: Turn power off for 30 seconds, then restore. Check diagnostic codes.

Service: 1-800-555-HEAT; www.gaffers-sattler.com