Heat Exchanger Experts Residential Furnace Inspection Manual

The Heat Exchanger Experts Residential Furnace Inspection Manual provides comprehensive guidelines for professional furnace inspection, maintenance, and safety procedures. This manual covers visual inspection techniques, combustion analysis, heat exchanger evaluation, airflow measurement, safety controls testing, and maintenance protocols for residential heating systems. Below are key sections for safety procedures, inspection protocols, diagnostic methods, maintenance requirements, and troubleshooting guidelines.

1. Safety Procedures 2. Inspection Equipment 3. Visual Inspection Protocol 4. Combustion Analysis 5. Heat Exchanger Evaluation 6. Airflow Measurement 7. Safety Controls Testing 8. Maintenance Requirements 9. Diagnostic Procedures 10. Regulatory Compliance 11. Troubleshooting Guide

Safety Procedures

Essential safety protocols for furnace inspection and maintenance operations.

Procedure	Description
Electrical Safety	Disconnect power at breaker before inspection
Gas Line Safety	Check for leaks with gas detector; shut off gas if detected
Carbon Monoxide	Use CO detector; ensure proper ventilation
Personal Protective Equipment	Wear safety glasses, gloves, and respirator as needed
Fire Safety	Keep flammable materials away from furnace area
Lockout/Tagout	Secure electrical and gas sources during work
Ventilation Check	Ensure adequate combustion air and exhaust
Hot Surface Warning	Allow furnace to cool before internal inspection

Inspection Equipment

Required tools and instruments for comprehensive furnace inspection.

Combustion Analyzer: Measures CO, CO2, O2, and efficiency
Digital Manometer: Tests gas pressure and draft
CO Detector: Monitors carbon monoxide levels
Inspection Camera: Visual examination of heat exchanger
Thermometer: Temperature differential measurement
Multimeter: Electrical system testing
Smoke Pencil: Airflow pattern visualization
Gas Leak Detector: Identifies fuel gas leaks

WARNING! Use calibrated equipment only; verify instrument accuracy before use.

Visual Inspection Protocol

Systematic visual examination of furnace components and condition.

Exterior Inspection: Check cabinet, panels, and clearances
Vent System: Examine flue pipes, connections, and terminations
Burner Assembly: Inspect for corrosion, damage, or blockages
Heat Exchanger: Look for cracks, rust, or deterioration
Electrical Components: Check wiring, connections, and condition
Drain System: Verify condensate drain operation
Air Filters: Inspect cleanliness and proper installation
Gas Connections: Check for leaks and proper fittings

CAUTION! Document all findings with photos and detailed notes.

Combustion Analysis

Oxygen Levels: 3-9% for natural gas; 4-11% for propane
Carbon Monoxide: Maximum 100 ppm in flue gases
Carbon Dioxide: 8-10% for natural gas; 9-11% for propane
Stack Temperature: 300-500°F above supply air temperature
Combustion Efficiency: Minimum 80% for standard furnaces
Draft Pressure: -0.01 to -0.05 inches WC for natural draft
Gas Pressure: 3.5" WC natural gas; 11" WC propane
Temperature Rise: 35-65°F for most residential furnaces

Heat Exchanger Evaluation

Comprehensive assessment of heat exchanger integrity and performance.

Inspection Methods: Visual examination, combustion gas analysis, pressure testing, borescope inspection.

Primary Cell Inspection: Check for cracks, holes, corrosion, or separation. Secondary Heat Exchanger: Examine for blockage, corrosion, or leakage. Crack Detection: Use bright light method or electronic crack detector. Pressure Test: Apply negative pressure to detect combustion gas leakage. Performance Indicators: Elevated CO levels, condensation in burners, sooting patterns.

Airflow Measurement

Assessment of air delivery system performance and efficiency.

Turn on furnace and allow to reach operating temperature
Measure temperature rise across heat exchanger
Calculate CFM using manufacturer's specifications
Check static pressure at filter and evaporator coil
Verify blower operation and speed settings
Inspect ductwork for restrictions or leaks

Tip: Compare measured airflow to manufacturer's specifications for optimal performance.

Safety Controls Testing

Verification of furnace safety system operation and reliability.

High Limit Control: Test manual reset and automatic functions
Flame Rollout Switch: Verify proper shutoff during flame rollout
Pressure Switch: Test for proper operation and timing
Flame Sensor: Check for proper current and cleanliness
Ignition System: Verify spark or hot surface igniter operation
Gas Valve: Test for proper opening and closing sequences
Blower Door Switch: Ensure safety interlock function
Vent Safety Switches: Confirm draft and pressure safety

WARNING! Never bypass safety controls; replace faulty components immediately.

Maintenance Requirements

Scheduled maintenance procedures for optimal furnace performance and longevity.

Diagnostic Procedures

Systematic troubleshooting approach for common furnace problems.

Follow diagnostic flow charts for specific symptoms. Use manufacturer error codes when available. Verify power supply and thermostat signals first. Test safety controls in sequence. Check gas supply and ignition system. Verify flame establishment and sensor operation. Monitor system pressures and temperatures.

CAUTION! Document diagnostic process and findings for reference.

Regulatory Compliance

Adherence to industry standards, codes, and manufacturer requirements.

NFPA 54: National Fuel Gas Code compliance. UL Standards: Component certification requirements. Local Building Codes: Installation and clearance specifications. Manufacturer Specifications: Warranty and performance guidelines. EPA Regulations: Venting and efficiency standards. ASHRAE Guidelines: Air quality and ventilation requirements. For technical support, contact Heat Exchanger Experts at 1-800-HEAT-EXP or visit www.heatexchangerexperts.com.

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
No heat	Thermostat, power, gas valve	Check thermostat setting; verify power; test gas valve operation
Insufficient heat	Airflow, filter, heat exchanger	Check filter; measure airflow; inspect heat exchanger
Frequent cycling	Filter, limit switch, airflow	Replace filter; test limit switch; verify proper airflow
Unusual noises	Blower, motor, heat exchanger	Inspect blower wheel; check motor bearings; examine heat exchanger
Burner won't ignite	Ignition, gas supply, safety	Test igniter; verify gas pressure; check safety controls
High CO readings	Heat exchanger, combustion	Inspect heat exchanger; adjust air-fuel mixture; check venting

Reset Procedure: Power cycle furnace; reset safety controls as needed.

Technical Support: 1-800-HEAT-EXP; www.heatexchangerexperts.com