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Goodman AC Unit Will Not Turn On Causes

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Quick answer

If your Goodman AC won't turn on, first check the power supply, thermostat settings, and circuit breaker. A tripped breaker or faulty thermostat is often the cause. Reset the breaker and ensure the thermostat is set correctly.

Confirm the symptom

Tools and prep

Step-by-step troubleshooting

  1. Check Power Supply
    Do: Verify the AC unit is receiving power from the electrical panel.
    Observe: Confirm the circuit breaker is in the 'ON' position and not tripped.
    Means: The unit has no power due to a tripped breaker or blown fuse.
    Next: Reset the breaker or replace the fuse if necessary.
  2. Inspect Thermostat
    Do: Check the thermostat settings and battery.
    Observe: Ensure the thermostat is set to 'COOL' and the temperature is lower than room temperature. Replace batteries if low.
    Means: Incorrect settings or dead batteries prevent the AC from starting.
    Next: If the thermostat is functioning, move to the next step.
  3. Test Emergency Switch
    Do: Locate and check the emergency shutoff switch near the outdoor unit.
    Observe: The switch may be in the 'OFF' position or tripped.
    Means: The emergency switch is manually turned off or tripped due to an overload.
    Next: Turn the switch back to 'ON' and attempt to restart the AC.
  4. Examine Contactor Relay
    Do: Inspect the contactor relay inside the outdoor unit's electrical panel.
    Observe: The relay may be burnt, stuck, or not engaging when the thermostat calls for cooling.
    Means: A faulty contactor relay prevents power from reaching the compressor.
    Next: Replace the contactor relay if it's damaged or not functioning.
  5. Check Capacitor
    Do: Look at the capacitor in the outdoor unit for signs of damage or bulging.
    Observe: A swollen or leaking capacitor indicates failure.
    Means: A bad capacitor can prevent the motor from starting.
    Next: Replace the capacitor with a compatible model.
  6. Test Motor and Compressor
    Do: Use a voltage tester to check for power at the motor and compressor terminals.
    Observe: If power is present but the motor/compressor does not run, there may be an internal failure.
    Means: A failed motor or compressor requires professional diagnosis.
    Next: Contact a licensed HVAC technician for further inspection.

Common causes

CauseLikelihoodDifficultyPart often needed
Tripped Circuit Breaker
The circuit breaker trips to protect against electrical overload.
CommonEasyCircuit breaker
Dead Thermostat Battery
Low battery power can prevent the thermostat from sending signals to the AC unit.
CommonEasyThermostat batteries
Faulty Contactor Relay
A damaged or worn-out contactor relay cannot send power to the compressor.
SometimesEasy–MediumContactor relay
Failed Capacitor
A capacitor stores electrical charge to start the motor; failure prevents startup.
SometimesMediumCapacitor
Motor or Compressor Failure
Internal damage or wear can cause the motor or compressor to stop working.
RareHardMotor or compressor replacement
Emergency Shutoff Switch Off
The emergency switch is manually turned off or tripped for safety.
SometimesEasyNone

Parts matching

Common parts needed for Goodman AC units include:

Always refer to your Goodman AC unit's owner's manual for exact part specifications and compatibility.

When to call a professional

FAQ

How do I know if my Goodman AC capacitor is bad?

Look for physical signs like bulging, leaking, or a humming noise from the capacitor. If it's swollen or shows visible damage, it likely needs replacement.

Can a bad thermostat prevent my Goodman AC from turning on?

Yes, a dead or faulty thermostat can prevent the AC from receiving signals. Replace the batteries or test the thermostat with a multimeter to confirm.

Why did my Goodman AC stop working suddenly?

Sudden failure can be due to a tripped breaker, blown fuse, or a component like the capacitor or contactor relay failing. Check these components first.

Is it safe to reset the circuit breaker for my Goodman AC?

Yes, resetting the breaker is safe if done carefully. Turn off the unit first, then reset the breaker. If it trips again, consult a professional.