Unlock the Right Part
for Your Repair
Find the exact part you need
Enter your model number to see parts that fit your machine.
Price Match Guarantee
In-stock parts ship the same day
365-Day Return Policy
Price Match GuaranteeChoose Product
Identify Problem
03
Find Solutions
HomeRepair HelpMedallion Central A/C RepairMedallion Central air conditioner won't turn on Repair
Medallion Central air conditioner won't turn on
If your Medallion central air conditioner won't turn on, start with the low-voltage control circuit and work through the most likely causes in order. A failed transformer may not send the 24-volt signal needed to energize the contactor and start the condensing unit. Next, a defective furnace control board can prevent power from reaching the contactor or blower motor. If the thermostat display is blank, replace its batteries, then check for an incoming power problem, such as a tripped circuit breaker, blown fuse, or power switch turned off at the furnace or air handler. A faulty wall thermostat or thermostat wiring is less common but can stop the cooling signal from reaching the control board through the thermostat wire. You can check basic settings, batteries, switches, and visible fuses yourself, but testing 24-volt circuits and working around 240V wiring, the disconnect box, contactor, or other line-voltage components should be handled by a qualified HVAC technician. Refrigerant work is not indicated for this symptom, but any sealed-system repair requires EPA 608 certification. Enter your model number to find the exact Medallion replacement transformer, control board, thermostat, or related part for your central air conditioner.
01 - Medallion 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.
Enter model number to search for the required part specific to your product
Highly Likely
02 - Medallion 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 - Medallion 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 - Medallion 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 Medallion central air conditioner not turning on?
What should I check if my Medallion AC thermostat is not turning on the air conditioner?
Why is my Medallion AC condenser not turning on even though the thermostat works?
How do I find the correct Medallion central air conditioner replacement part?
When should I call a licensed HVAC technician for a Medallion AC that will not start?
Shop by Medallion Central Air Conditioner Parts
Our Story
Family-owned and operated since 1912, Burke America Parts Group is the longest-running genuine appliance, HVAC, and outdoor power equipment parts solution in North America. At Repair Clinic, we're proud to be an international brand trusted by the pros as well as the DIY community.
About Repair Clinic
© 2026 RepairClinic.com