What You’ll Learn:

Heat Strip Wiring Safety

• Undersized wire dangers and fire hazards
• Proper wire gauge sizing for heat kits
• Correct breaker and wire combinations
• Common retrofit issues when replacing furnaces with heat pumps

Heat Pump Defrost Cycle Explained

• Thermostat vs thermistor defrost systems
• Standard carrier defrost boards
• Demand defrost boards with coil and ambient sensors
• How to test defrost operation in the field

Troubleshooting Defrost Issues

• Testing defrost sensors and thermistors
• Identifying ice buildup vs normal frost
• Diagnosing premature or stuck defrost cycles
• Manual defrost testing procedures

Setting Customer Expectations

• Explaining normal defrost sounds and cold air
• When defrost is working properly vs system failure
• Why units make “horrible sounds” during defrost switching

Key Safety Reminders:

• Undersized wiring causes wire melt and potential house fires
• Always verify wire gauge matches heat kit requirements
• Check for rodent damage on defrost sensor wiring
• Maximum 10-minute defrost cycles on standard boards