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HomeRepair HelpGibson Central A/C RepairGibson Central air conditioner won't turn on Repair
Gibson Central air conditioner won't turn on
Is your Gibson central air conditioner not turning on, or is the air conditioner not starting when the thermostat calls for cooling? The most likely cause is a failed transformer, which supplies the 24-volt signal from the furnace or air handler to the contactor. A defective control board is another possibility if the contactor is not receiving 24 volts or the blower motor is not getting power. Next, check the wall thermostat batteries if the display is blank, then check for an incoming power problem, such as a tripped circuit breaker, blown fuse, or turned-off service switch. A faulty Gibson wall thermostat or thermostat wiring can also prevent the condensing unit from starting if the cooling signal cannot travel through the thermostat wire. You can enter your model number to find the exact replacement transformer, control board, thermostat, or other part for your Gibson central air conditioner. Checking low-voltage components may be suitable for a capable DIYer, but testing or replacing parts inside the furnace, air handler, disconnect box, or condensing unit can involve 240-volt line voltage. Turn off power before inspection, and have a qualified HVAC technician handle line-voltage diagnosis or repairs beyond your comfort level.
01 - Gibson 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 - Gibson 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 - Gibson 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 - Gibson 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 Gibson central air conditioner not turning on?
What should I check if my AC thermostat is not working or is blank?
Why is my outdoor AC unit not turning on when the thermostat is calling for cooling?
How do I test the Gibson AC transformer or control board?
How do I find the correct replacement part for my Gibson central air conditioner?
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