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Error code reference

Goodman Heat Pump Error Code 05

Open circuit

Goodman codesGoodman heat pump codes

Open circuit - power disconnected, failed compressor protector, or compressor not properly wired to control.

First step from the service manual

Check circuit breakers and fuses. Check wiring to unit.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What 05 means on a Goodman heat pump

Goodman heat pump error code 05 indicates an open circuit condition in the compressor circuit. This means the control board is detecting that electrical continuity to the compressor is broken or absent. The control board monitors the compressor circuit and flags this fault when it cannot confirm a complete, functioning electrical path through the compressor and its associated protective components. This is a hard fault that will prevent the compressor from operating, leaving the system unable to provide heating or cooling.

The three primary causes align with the three conditions listed in the fault definition. First, power may be disconnected or interrupted, which includes tripped circuit breakers, blown fuses in the disconnect box, or a disconnected power supply to the outdoor unit. Second, the compressor protector, which typically includes the internal overload and sometimes an external klixon-style thermal overload device, may have failed open or tripped due to overheating. Third, the compressor wiring may be improperly connected or damaged, creating an open condition in the circuit between the control board and the compressor terminals.

Diagnosis should begin at the circuit breakers and fuse block, confirming the outdoor unit is receiving proper voltage. From there, inspect all wiring connections at the compressor terminals and the control board. If power and wiring check out, the compressor protector should be tested for continuity. A failed or tripped protector will show infinite resistance across its terminals. Allow the compressor to cool before retesting the protector, as thermal overloads will reset once the compressor temperature drops to a safe level.

Source: manufacturer service documentation.

Common causes of 05

  1. 01

    Tripped circuit breaker or blown fuse

    Wiring / connection

    A tripped breaker at the main panel or a blown fuse in the outdoor disconnect box will cut power to the compressor circuit and trigger this fault. Check both the main panel breaker and the fuse block in the outdoor disconnect for continuity or proper position.

  2. 02

    Loose or disconnected compressor wiring

    Wiring / connection

    Vibration over time can loosen terminal connections at the compressor or at the control board, creating an open circuit. Inspect all wiring at the compressor run, start, and common terminals as well as the wiring harness connections at the control board.

  3. 03

    Tripped or failed compressor protector

    Part replacement

    The compressor protector, an internal or external thermal overload device, opens the circuit when the compressor overheats. If tripped, allow the unit to cool and retest for continuity across the protector terminals. A failed protector will show no continuity even after cooling and will need to be replaced.

  4. 04

    Damaged or burned compressor wiring

    Part replacement

    Wiring insulation can crack, burn, or be damaged by rodents, causing an open or broken conductor in the compressor circuit. Visually inspect all wiring in the outdoor unit for signs of burning, fraying, or physical damage.

  5. 05

    Failed compressor with open winding

    Part replacement

    An internally failed compressor may have an open winding, which presents as an open circuit to the control board. Use a multimeter to check resistance between the compressor terminals. An open reading between any two terminals indicates a failed compressor.

See the test procedure for each cause

Frequently asked questions about 05

What does 05 mean on a Goodman heat_pump?
Error code 05 on a Goodman heat pump indicates an open circuit condition in the compressor circuit. The control board cannot detect a complete electrical path to the compressor, which may be caused by a disconnected power supply, a failed compressor protector, or improper wiring between the compressor and the control board. The compressor will not run while this fault is active.
Can I fix Goodman heat pump error code 05 myself?
Some causes of error code 05 are within reach of a knowledgeable DIYer. Checking and resetting a tripped circuit breaker or replacing a blown fuse in the outdoor disconnect are straightforward tasks. Inspecting wiring connections at the compressor terminals is also possible with basic electrical knowledge and the power disconnected. However, testing the compressor protector and compressor windings with a multimeter, or replacing any of these components, is best handled by a certified HVAC technician.
Is it safe to keep running my Goodman heat pump with error code 05?
Error code 05 will prevent the compressor from operating, so the system is essentially protecting itself by not running. There is no immediate safety risk in the sense of fire or explosion from this fault alone, but you should not attempt to bypass or ignore the fault. Continuing to attempt system restarts without diagnosing the root cause could cause further damage to the compressor or wiring.
How much does it cost to repair Goodman heat pump error code 05?
Repair costs depend heavily on what is causing the open circuit. Replacing a blown fuse or resetting a breaker costs little to nothing beyond a service call fee, which typically ranges from $75 to $150. Replacing a compressor protector or repairing damaged wiring may run $150 to $400 including parts and labor. A failed compressor is the most expensive outcome, with replacement costs ranging from $800 to $2,500 or more depending on the unit size and refrigerant type.
Will resetting my Goodman heat pump clear error code 05?
Resetting the unit by cycling the power may temporarily clear the fault code, but the error will return if the underlying cause has not been corrected. If the compressor protector tripped due to overheating, allowing the unit to cool before resetting may restore operation temporarily. However, a persistent open circuit caused by failed wiring, a damaged protector, or a failed compressor will continue to trigger code 05 until the defective component is repaired or replaced.

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