NATE Heat Pump Service Practice Tests

This practice test covers the O-type and B-type reversing valve conventions, how to diagnose reversed heating/cooling operation, and basic solenoid coil electrical testing. You will also see questions on thermostat wiring mistakes and how defrost interacts with the O/B convention.

This practice test covers how and why a heat pump defrost cycle happens: why frost forms on the outdoor coil, what triggers and ends a defrost cycle, and why auxiliary heat often runs at the same time. Several scenario questions cover diagnosing defrost control problems.

This practice test covers the difference between automatic auxiliary heat and manual emergency heat, when each one is used, and how to recognize when a system is relying on backup heat more than it should. You will also see a few questions connecting this topic to COP and defrost.

This practice test focuses on balance point and how a heat pump's heating capacity changes with outdoor temperature. You will review how heat loss, equipment sizing, and climate affect when auxiliary heat is needed. A few questions on emergency heat and dual-fuel systems are mixed in for review.

This practice test covers COP, HSPF, and SEER, the main efficiency ratings used for heat pumps. You will practice simple COP calculations and review why heat pumps carry both a heating and a cooling efficiency rating. A few questions on balance point and refrigerant basics are mixed in for review.

This practice test focuses on the compressor crankcase heater and cold-weather startup risks. You will review refrigerant migration, oil dilution, and oil slugging, plus how to field-check crankcase heater operation. A few questions on COP and dual-fuel systems are mixed in for review.

This test covers dual-fuel (hybrid) heat pump systems — how a heat pump pairs with a gas furnace as backup instead of electric strips, and how the control strategy decides which one runs.

This test covers refrigerant circuit diagnostics specific to heat pumps — how superheat and subcooling measurement points swap roles between heating and cooling mode, and low-ambient cooling controls.

A mixed scenario-based review combining reversing valves, defrost, auxiliary/emergency heat, balance point, efficiency, and refrigerant circuit diagnostics into realistic troubleshooting calls.