mypros+
Error code reference

Goodman Heat Pump Error Code 04

Locked rotor

Goodman codesGoodman heat pump codes

Locked rotor - compressor bearings seized, failed run capacitor, faulty run capacitor wiring, or low line voltage.

First step from the service manual

Check compressor operation; repair/replace as needed. Check run capacitor.

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

MyPros+ Max

Get the full diagnostic procedure for 04.

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

What 04 means on a Goodman heat pump

Error code 04 on a Goodman heat pump indicates a locked rotor condition, which means the compressor motor has failed to start or rotate properly. The control board detects this fault when the compressor draws abnormally high current during a start attempt without successfully spinning up. A locked rotor condition places extreme stress on the electrical system and can trip internal protectors within the compressor itself.

The most common causes fall into four categories: seized compressor bearings, a failed run capacitor, faulty wiring to the run capacitor, or insufficient line voltage at the unit. Seized bearings inside the compressor prevent the motor shaft from turning, resulting in a stalled rotor and a high-current fault. A failed run capacitor removes the phase shift needed to generate starting torque, leaving the compressor unable to overcome initial inertia. Low line voltage, typically below the unit's rated operating range, similarly reduces available torque and can cause repeated failed start attempts.

Diagnosis should begin with measuring line voltage at the disconnect to confirm it is within the acceptable operating range for the unit. The run capacitor should then be tested with a capacitance meter and compared against its rated microfarad value printed on the label. A capacitor reading significantly outside tolerance requires replacement. If the capacitor and voltage check out, the compressor itself should be evaluated for winding resistance, continuity to ground, and the ability to rotate freely. A compressor with seized bearings typically cannot be repaired in the field and requires full compressor replacement.

Source: manufacturer service documentation.

Common causes of 04

  1. 01

    Failed run capacitor

    Part replacement

    A run capacitor that has lost capacitance or failed completely cannot provide the phase shift required for the compressor motor to start. Test the capacitor with a capacitance meter; a reading significantly outside the rated microfarad value confirms failure.

  2. 02

    Seized compressor bearings

    Part replacement

    Internal bearing failure locks the compressor rotor in place, preventing the motor from spinning. This typically produces a loud humming sound during the failed start attempt and cannot be repaired without full compressor replacement.

  3. 03

    Low line voltage

    Wiring / connection

    Insufficient voltage at the unit reduces available motor torque and can prevent the compressor from starting under load. Measure voltage at the disconnect and at the contactor while the unit attempts to start to confirm voltage does not sag below acceptable levels.

  4. 04

    Faulty run capacitor wiring

    Wiring / connection

    Loose, corroded, or broken wiring connections to the run capacitor can interrupt the capacitor circuit even when the capacitor itself is good. Inspect all terminals and wire connections at the capacitor for damage or poor contact.

See the test procedure for each cause

Frequently asked questions about 04

What does 04 mean on a Goodman heat_pump?
Error code 04 on a Goodman heat pump indicates a locked rotor fault, meaning the compressor failed to start or spin up properly. The control board detects abnormally high current during a start attempt and shuts down the system to prevent damage. The cause is typically a failed run capacitor, low incoming voltage, faulty capacitor wiring, or seized compressor bearings.
Can I fix error code 04 on my Goodman heat pump myself?
Some causes of error code 04 are within reach of an experienced DIYer. Checking line voltage at the disconnect and inspecting capacitor wiring connections are straightforward steps. However, testing and replacing a run capacitor involves working near components that can hold a dangerous electrical charge even when power is off, and a seized compressor requires professional replacement. Use extreme caution or call a licensed technician if you are not comfortable working with high-voltage components.
Is it safe to keep running my Goodman heat pump with error code 04?
No, you should not continue attempting to operate the system with an active locked rotor fault. Repeated failed start attempts can overheat the compressor motor windings, cause the internal overload protector to fail, and potentially damage the contactor or other electrical components. Address the fault before resuming normal operation.
How much does it cost to repair error code 04 on a Goodman heat pump?
Repair cost depends heavily on the root cause. A run capacitor replacement is typically a lower-cost repair, often ranging from $80 to $250 including labor. If low line voltage is caused by a utility or wiring issue, electrical service work may add additional cost. A seized compressor is the most expensive outcome, with compressor replacement on a heat pump generally ranging from $1,200 to $2,800 or more depending on the unit size and refrigerant type.
Will resetting my Goodman heat pump clear error code 04?
Resetting the system by cycling power may temporarily clear the fault code and allow another start attempt, but it will not resolve the underlying problem. If the root cause such as a failed capacitor or seized compressor has not been corrected, the unit will fault again, often immediately. Repeated reset attempts without diagnosis can accelerate damage to the compressor and electrical components.

Related Goodman heat pump codes

All Goodman heat pump codes
View all 28 Goodman heat pump codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass