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HomeRepair HelpGoodman Central A/C RepairGoodman Central air conditioner won't turn on Repair
Goodman Central air conditioner won't turn on
If your Goodman central air conditioner won't turn on, the most likely cause is a failed transformer, which supplies the 24-volt signal that lets the thermostat energize the contactor and start the condensing unit. A defective furnace control board is another highly likely cause, especially when the contactor receives no 24 volts or the furnace blower motor has no power. Next, check for dead wall thermostat batteries, a tripped circuit breaker, blown fuse, or a turned-off power switch at the furnace or air handler. If those checks are good, a faulty Goodman wall thermostat or thermostat wiring may not be sending the cooling signal through the thermostat wire to the control board. This troubleshooting applies when the air conditioner is not turning on, the AC won't turn on, or the central air conditioner won't start. Enter your model number to find the exact Goodman transformer, control board, thermostat, fuse, or other replacement part for your specific system. Checking batteries and thermostat settings is generally DIY-friendly, but testing or replacing components inside the furnace, air handler, disconnect box, or condensing unit can involve 240V line voltage. Turn off power first, and hire a qualified HVAC technician for electrical work beyond your skill level.
01 - Goodman Central Air Conditioner Transformer
The furnace control board sends a low voltage signal of 24 volts to the thermostat. When the themostat cooling contacts close, a 24 volt signal is sent to the contactor coil, closing the high voltage circuit and sending power to the condensing unit components. Some furnaces have a separate transformer for the 24 volt circuit, so if the contactor is not receiving the proper voltage when the thermostat cooling contacts are closed, it's likely this transformer has failed and the component will need to be replaced.
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Highly Likely
02 - Goodman Central Air Conditioner Control Board
If the central air condensing unit contactor is not receiving 24 volts or power is not getting to the furnace blower motor, a possible cause is a defective furnace control board. While this is not a common problem, if all other potentially faulty components are working properly, the control board should be replaced.
Highly Likely
03 - Wall Thermostat Batteries
Most wall thermostats are either powered by an enclosed battery or by the furnace or air handler transformer. If the thermostat display is dead, you can remove the thermostat cover and look for replaceable batteries. Replace the batteries if needed and check operation.
Common
04 - Incoming Power Problem
Check to see if there is power to the furnace or air handler. One or more indicator lights on the control board should be illuminated. If there is no power to the furnace or air handler, check to see if a circuit breaker has tripped or a fuse has blown. Confirm the power switch on the side of the unit is turned on.
Common
05 - Goodman Central Air Conditioner Wall Thermostat
The furnace control board sends a low voltage signal of 24 volts to the contactor through the wall thermostat. When the contactor receives the signal from the wall thermostat, it closes the circuit, sending voltage to the condensing unit components. There should be 24 volts between the common (“C”) and yellow (“Y”) thermostat wire terminals on the furnace control board when the wall thermostat is in the cooling mode. You can check for this voltage with a multimeter. If voltage is not reaching the contactor, it's likely the wall thermostat is defective and will need to be replaced.
Less Common
06 - Goodman Central Air Conditioner Wifi Thermostat
The furnace control board sends a low voltage signal of 24 volts to the contactor through the WiFi thermostat. When the contactor receives the signal from the WiFi thermostat, it closes the circuit, sending voltage to the condensing unit components. There should be 24 volts between the common (“C”) and yellow (“Y”) thermostat wire terminals on the furnace control board when the WiFi thermostat is in the cooling mode. You can check for this voltage with a multimeter. If voltage is not reaching the contactor, it's likely the WiFi thermostat is defective and will need to be replaced.
Less Common
Frequently Asked Questions
Why is my Goodman central air conditioner not turning on?
What should I check when my Goodman AC won't turn on and the thermostat is blank?
How do I know if the Goodman AC transformer, thermostat, or contactor is bad?
Could a Goodman control board keep the central AC from starting?
How do I find the correct replacement part for my Goodman central air conditioner?
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