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HomeRepair HelpPhilco Central A/C RepairPhilco Central air conditioner won't turn on Repair
Philco Central air conditioner won't turn on
If your Philco central air conditioner won't turn on, the problem is usually in the low-voltage control circuit rather than the refrigerant system. The most likely cause is a failed transformer, which should supply 24 volts from the furnace or air handler to the thermostat and contactor. Next, a defective furnace control board may prevent the contactor from receiving the signal needed to start the outdoor condensing unit. If the thermostat display is blank, check and replace its batteries. Then check for an incoming power problem, including 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 either can fail to send the cooling signal through the thermostat wire. You can inspect batteries, switches, and visible wiring yourself, but testing 24-volt circuits requires care. The furnace, air handler, disconnect box, and condensing unit also contain hazardous 240V line voltage, so have a qualified technician handle live electrical testing or repairs beyond basic checks. Enter your Philco model number to find the exact replacement transformer, control board, thermostat, fuse, or other part for your central air conditioner.
01 - Philco 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 - Philco 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 - Philco 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 - Philco 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 won't my Philco central air conditioner turn on?
What should I check if my AC thermostat is not working or not turning on the air conditioner?
Why is my AC condenser not turning on when the thermostat calls for cooling?
Could a failed transformer cause my central air conditioner not to start?
How do I find the correct Philco central air conditioner replacement part?
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