Price Match GuaranteeAir Conditioner Repair FAQs: Troubleshooting, Parts & Fixes
Start with airflow, power, and the temperature setting before replacing parts. A clogged filter, dirty condenser coils, failed capacitor, faulty thermistor, bad thermostat, weak fan motor, or compressor issue can all keep an air conditioner from cooling. Clean or replace the filter, inspect the coils, confirm the fan runs, and use a multimeter to test electrical parts before ordering replacements. Use air conditioner not cooling troubleshooting for the full symptom path and Air Conditioner Parts to find model-specific replacement parts.
Yes. A clogged filter restricts airflow through the unit, reduces cooling capacity, and can cause evaporator coils to frost over. Many standalone air conditioner filters can be cleaned with soap and water, but filters that are damaged or heavily clogged should be replaced. Find matching replacement AC filters on our air conditioner filter parts page.
Frozen coils usually point to restricted airflow, a dirty evaporator coil, a clogged or damaged filter, a weak fan motor, a failed blower motor, or a sealed system problem. Check the filter first, then inspect the evaporator coil and blower wheel. If the coils freeze in only one area or a refrigerant issue is suspected, a licensed technician should handle the sealed system repair. See air conditioner coils freezing troubleshooting for additional problems, solutions, and replacement parts for the fix.
A bad fan motor may hum without spinning, stop after running briefly, spin only when pushed by hand, make grinding noises, or fail even when voltage is reaching the motor. Check that the fan blade turns freely and test incoming voltage with a multimeter. Replace the fan motor if it receives proper power but will not run. See air conditioner fan not working troubleshooting and shop air conditioner motor parts for matching replacements.
The compressor may not run because of a faulty temperature control thermostat, temperature control board, thermistor, overload, run capacitor, dual run capacitor, start relay, selector switch, relay board, main control board, incoming power issue, or the compressor itself. Check more common electrical parts before assuming the compressor has failed. If the compressor is defective, replacement should be handled by a licensed technician. See air conditioner compressor will not run troubleshooting for all common problems and solutions when your AC compressor is not turning on.
First replace the remote batteries and confirm the unit can still be controlled manually. If the control panel works but the remote does not, the remote may be defective. If multiple remotes fail or the unit does not receive signals, the infrared receiver on the main control board may be the issue. See air conditioner remote control troubleshooting and browse air conditioner remote control parts by model number for replacement AC remote control options.
Yes. A run capacitor can keep the compressor or fan motor from starting, while a dual run capacitor can affect both the compressor and fan motor. Look for bulging, leaking, or a burnt odor, then test the capacitor with a multimeter that can measure capacitance or continuity as appropriate. Replace the capacitor if it cannot hold and release a charge. If you know it’s a bad capacitor, shop air conditioner capacitor parts by model number.
A humming sound with no cooling can point to a failed capacitor, stuck fan blade, bad fan motor, compressor overload, start relay, or compressor problem. Turn the unit off if the fan or compressor is not starting because continued operation can overheat electrical parts. Test the capacitor and inspect the fan blade before moving to control or compressor-related parts.
Confirm the unit is plugged in, the outlet has power, the LCDI power cord has not tripped, and the breaker or fuse is not open. If the unit has power but will not run, check the control board, main control board, user control and display board, selector switch, and incoming power path. See air conditioner will not run troubleshooting for additional guidance on troubleshooting and repairing air conditioners that will not turn on.
A tripping breaker can be caused by a damaged LCDI power cord, shorted condenser fan motor, shorted dual shaft fan motor, bad blower motor, damaged wire harness, shorted control board, or weak household breaker. If you smell burning or see damaged wiring, stop using the unit. Electrical testing should be done carefully, and household breaker issues should be handled by a licensed technician. See air conditioner breaker troubleshooting for additional troubleshooting guidance.
If the air conditioner runs continuously, the condenser coils may be dirty, the air filter may be clogged, the thermostat may be shorted, the thermistor may be defective, or the control board may be sending continuous voltage. A sealed system problem can also prevent the unit from reaching the set temperature. See air conditioner will not turn off troubleshooting to narrow the cause, and check AC sensor and thermistor parts if the unit is not sensing temperature correctly.
Short cycling can happen when a control board, main control board, user control and display board, thermistor, temperature sensor, or temperature control thermostat is malfunctioning. It can also happen when the air conditioner is oversized for the room or outdoor temperatures are mild. See air conditioner short cycling troubleshooting and review common problems, solutions, and replacement parts if the unit cycles before the room is comfortable.
Low airflow can be caused by a clogged air filter, dirty evaporator coil, dirty condenser coil, weak fan motor, bad dual shaft fan motor, bad condenser fan motor, or blower restriction. Clean or replace the filter first, then inspect the coils and fan motor operation. See air conditioner not blowing enough troubleshooting for all common problems and solutions when your AC is not blowing enough air.
Depending on the model, a thermostat, thermistor, temperature sensor, user control and display board, temperature control board, or main control board may control temperature. The thermostat or thermistor senses air temperature, while the board uses that signal to cycle the fan and compressor. Use air conditioner poor temperature control troubleshooting for common problems and solutions related to AC temperature control.
A thermistor changes resistance as air temperature changes. Disconnect power, access the thermistor, and use a multimeter to test continuity or resistance. Compare the reading to the temperature and resistance values in the owner’s manual or wiring documentation. If you need to replace your thermistor enter your model number on our AC thermistor replacement page to find the exact part for your model.
Replace a control board only after checking more common parts such as the filter, capacitor, fan motor, thermostat, thermistor, overload, selector switch, and incoming power. Control boards are often misdiagnosed. Signs of board failure can include burnt components, no output voltage to a working part, or controls that will not respond after power and sensors test correctly. If you know you need to replace the AC control board enter your model number on air conditioner circuit board replacement parts to find the right part for the fix.
Noise can come from a worn compressor, failing dual shaft fan motor, damaged fan blade, condenser fan motor, fan motor, blower wheel, loose brace, blower motor, or bearing. Inspect both front and rear fan blades for rubbing or damage, check for loose braces, and listen for motor bearing noise. See air conditioner loud or noisy troubleshooting and related air conditioner bearing parts if the sound points to a rotating part.
Yes. A loose or damaged blower wheel can wobble on the motor shaft, scrape the housing, or create vibration. Tighten or replace the set screw if the wheel uses one. If the wheel is cracked, out of round, or still unstable, replace the blower wheel. Use air conditioner loud or noisy troubleshooting for additional guidance on problems, solutions, and shop blower wheel and fan blade parts for related replacement parts.
High humidity can result from a clogged filter, dirty condenser coils, dirty evaporator coil, poor airflow, thermostat issue, thermistor issue, control board issue, oversized air conditioner, or sealed system problem. The unit needs proper airflow and enough run time to remove moisture from the air. See air conditioner humidity troubleshooting to determine the cause and related solution.
Yes. Dirty condenser coils cannot release heat efficiently, so the air conditioner works harder and may run continuously while trying to cool the room. Clean the condenser coils according to the owner’s manual before replacing parts.
The sealed system includes refrigerant-related components such as the compressor and coils. A leak or restriction can cause poor cooling, frozen coils in one area, high humidity, or continuous operation. Because sealed system diagnosis and repair require specialized tools and certification, a licensed technician should perform this work.
Use a licensed technician for sealed system repairs, refrigerant leaks, compressor replacement, household electrical breaker replacement, and any repair where local code requires certified service. DIYers can often handle filters, remote controls, knobs, covers, side curtains, fan blades, and certain model-specific electrical parts when proper safety steps are followed. Start with the air conditioner repair help hub to determine the problem before ordering parts.
Use the model number from your air conditioner’s rating plate and enter it on RepairClinic.com to filter parts that fit your unit. You can also search by part number if you already have it. Start from Air Conditioner Parts or the air conditioner repair help page to narrow by symptom, brand, model, or part category.
Common DIY replacement parts include filters, remote controls, knobs, buttons, side curtains, covers, grilles, fan blades, blower wheels, brackets, power cords, and some capacitors or switches for users comfortable with safe electrical testing. Always disconnect power before opening the unit and match parts by model number. Start with air conditioner repair help and shop air conditioner capacitor parts when the symptom points to a starting problem.
For systems controlled by a wall thermostat, check the wall thermostat, WiFi thermostat, thermostat batteries, control board, incoming power, transformer, and thermostat wiring. If the thermostat display is dead, check replaceable batteries first. If the thermostat has power but does not send signals correctly, it may need replacement. See air conditioner wall thermostat troubleshooting for additional guidance on common problems and solutions when your wall thermostat is not working correctly or will not turn on.
Yes. Damaged thermostat wiring can stop the thermostat from sending signals to indoor or outdoor components. Inspect for loose connections, damaged insulation, or broken wires. Thermostat wiring can be checked for power or continuity with a multimeter, but wiring repairs should follow the unit’s diagram and applicable electrical codes. It may be best for electrical wiring work to be completed by a professional HVAC technician or electrician.
The fan motor should run when the compressor is on. If the compressor runs but the fan does not, check the fan motor, fan motor capacitor, dual run capacitor, condenser fan motor, blower motor, or selector switch. A non-running fan can cause overheating, poor cooling, and frozen coils.
If the fan runs but the compressor does not, check the temperature control thermostat, temperature control board, compressor overload, run capacitor, dual run capacitor, start relay, selector switch, thermistor, relay board, main control board, and compressor. Test the more common electrical parts before assuming the compressor itself has failed.
Yes. A selector switch directs voltage to components such as the fan motor or compressor. If the fan or compressor works intermittently when you press buttons or rotate the switch, or if you see arcing or smoke from the switch, replace the selector switch with the correct model-specific part. See air conditioner switch parts for replacement parts related to this issue.
The air conditioner model number is usually on a rating plate or label on the side of the unit, behind the front grille, near the control panel, on the frame, or on the exterior cabinet. The exact location varies by brand and model, so check the owner’s manual if the label is not visible. Use Repair Clinic’s air conditioner model number help page to find the label before ordering replacement parts.
Start with airflow, power, and the temperature setting before replacing parts. A clogged filter, dirty condenser coils, failed capacitor, faulty thermistor, bad thermostat, weak fan motor, or compressor issue can all keep an air conditioner from cooling. Clean or replace the filter, inspect the coils, confirm the fan runs, and use a multimeter to test electrical parts before ordering replacements. Use air conditioner not cooling troubleshooting for the full symptom path and Air Conditioner Parts to find model-specific replacement parts.
Yes. A clogged filter restricts airflow through the unit, reduces cooling capacity, and can cause evaporator coils to frost over. Many standalone air conditioner filters can be cleaned with soap and water, but filters that are damaged or heavily clogged should be replaced. Find matching replacement AC filters on our air conditioner filter parts page.
Frozen coils usually point to restricted airflow, a dirty evaporator coil, a clogged or damaged filter, a weak fan motor, a failed blower motor, or a sealed system problem. Check the filter first, then inspect the evaporator coil and blower wheel. If the coils freeze in only one area or a refrigerant issue is suspected, a licensed technician should handle the sealed system repair. See air conditioner coils freezing troubleshooting for additional problems, solutions, and replacement parts for the fix.
A bad fan motor may hum without spinning, stop after running briefly, spin only when pushed by hand, make grinding noises, or fail even when voltage is reaching the motor. Check that the fan blade turns freely and test incoming voltage with a multimeter. Replace the fan motor if it receives proper power but will not run. See air conditioner fan not working troubleshooting and shop air conditioner motor parts for matching replacements.
The compressor may not run because of a faulty temperature control thermostat, temperature control board, thermistor, overload, run capacitor, dual run capacitor, start relay, selector switch, relay board, main control board, incoming power issue, or the compressor itself. Check more common electrical parts before assuming the compressor has failed. If the compressor is defective, replacement should be handled by a licensed technician. See air conditioner compressor will not run troubleshooting for all common problems and solutions when your AC compressor is not turning on.
First replace the remote batteries and confirm the unit can still be controlled manually. If the control panel works but the remote does not, the remote may be defective. If multiple remotes fail or the unit does not receive signals, the infrared receiver on the main control board may be the issue. See air conditioner remote control troubleshooting and browse air conditioner remote control parts by model number for replacement AC remote control options.
Yes. A run capacitor can keep the compressor or fan motor from starting, while a dual run capacitor can affect both the compressor and fan motor. Look for bulging, leaking, or a burnt odor, then test the capacitor with a multimeter that can measure capacitance or continuity as appropriate. Replace the capacitor if it cannot hold and release a charge. If you know it’s a bad capacitor, shop air conditioner capacitor parts by model number.
A humming sound with no cooling can point to a failed capacitor, stuck fan blade, bad fan motor, compressor overload, start relay, or compressor problem. Turn the unit off if the fan or compressor is not starting because continued operation can overheat electrical parts. Test the capacitor and inspect the fan blade before moving to control or compressor-related parts.
Confirm the unit is plugged in, the outlet has power, the LCDI power cord has not tripped, and the breaker or fuse is not open. If the unit has power but will not run, check the control board, main control board, user control and display board, selector switch, and incoming power path. See air conditioner will not run troubleshooting for additional guidance on troubleshooting and repairing air conditioners that will not turn on.
A tripping breaker can be caused by a damaged LCDI power cord, shorted condenser fan motor, shorted dual shaft fan motor, bad blower motor, damaged wire harness, shorted control board, or weak household breaker. If you smell burning or see damaged wiring, stop using the unit. Electrical testing should be done carefully, and household breaker issues should be handled by a licensed technician. See air conditioner breaker troubleshooting for additional troubleshooting guidance.
If the air conditioner runs continuously, the condenser coils may be dirty, the air filter may be clogged, the thermostat may be shorted, the thermistor may be defective, or the control board may be sending continuous voltage. A sealed system problem can also prevent the unit from reaching the set temperature. See air conditioner will not turn off troubleshooting to narrow the cause, and check AC sensor and thermistor parts if the unit is not sensing temperature correctly.
Short cycling can happen when a control board, main control board, user control and display board, thermistor, temperature sensor, or temperature control thermostat is malfunctioning. It can also happen when the air conditioner is oversized for the room or outdoor temperatures are mild. See air conditioner short cycling troubleshooting and review common problems, solutions, and replacement parts if the unit cycles before the room is comfortable.
Low airflow can be caused by a clogged air filter, dirty evaporator coil, dirty condenser coil, weak fan motor, bad dual shaft fan motor, bad condenser fan motor, or blower restriction. Clean or replace the filter first, then inspect the coils and fan motor operation. See air conditioner not blowing enough troubleshooting for all common problems and solutions when your AC is not blowing enough air.
Depending on the model, a thermostat, thermistor, temperature sensor, user control and display board, temperature control board, or main control board may control temperature. The thermostat or thermistor senses air temperature, while the board uses that signal to cycle the fan and compressor. Use air conditioner poor temperature control troubleshooting for common problems and solutions related to AC temperature control.
A thermistor changes resistance as air temperature changes. Disconnect power, access the thermistor, and use a multimeter to test continuity or resistance. Compare the reading to the temperature and resistance values in the owner’s manual or wiring documentation. If you need to replace your thermistor enter your model number on our AC thermistor replacement page to find the exact part for your model.
Replace a control board only after checking more common parts such as the filter, capacitor, fan motor, thermostat, thermistor, overload, selector switch, and incoming power. Control boards are often misdiagnosed. Signs of board failure can include burnt components, no output voltage to a working part, or controls that will not respond after power and sensors test correctly. If you know you need to replace the AC control board enter your model number on air conditioner circuit board replacement parts to find the right part for the fix.
Noise can come from a worn compressor, failing dual shaft fan motor, damaged fan blade, condenser fan motor, fan motor, blower wheel, loose brace, blower motor, or bearing. Inspect both front and rear fan blades for rubbing or damage, check for loose braces, and listen for motor bearing noise. See air conditioner loud or noisy troubleshooting and related air conditioner bearing parts if the sound points to a rotating part.
Yes. A loose or damaged blower wheel can wobble on the motor shaft, scrape the housing, or create vibration. Tighten or replace the set screw if the wheel uses one. If the wheel is cracked, out of round, or still unstable, replace the blower wheel. Use air conditioner loud or noisy troubleshooting for additional guidance on problems, solutions, and shop blower wheel and fan blade parts for related replacement parts.
High humidity can result from a clogged filter, dirty condenser coils, dirty evaporator coil, poor airflow, thermostat issue, thermistor issue, control board issue, oversized air conditioner, or sealed system problem. The unit needs proper airflow and enough run time to remove moisture from the air. See air conditioner humidity troubleshooting to determine the cause and related solution.
Yes. Dirty condenser coils cannot release heat efficiently, so the air conditioner works harder and may run continuously while trying to cool the room. Clean the condenser coils according to the owner’s manual before replacing parts.
The sealed system includes refrigerant-related components such as the compressor and coils. A leak or restriction can cause poor cooling, frozen coils in one area, high humidity, or continuous operation. Because sealed system diagnosis and repair require specialized tools and certification, a licensed technician should perform this work.
Use a licensed technician for sealed system repairs, refrigerant leaks, compressor replacement, household electrical breaker replacement, and any repair where local code requires certified service. DIYers can often handle filters, remote controls, knobs, covers, side curtains, fan blades, and certain model-specific electrical parts when proper safety steps are followed. Start with the air conditioner repair help hub to determine the problem before ordering parts.
Use the model number from your air conditioner’s rating plate and enter it on RepairClinic.com to filter parts that fit your unit. You can also search by part number if you already have it. Start from Air Conditioner Parts or the air conditioner repair help page to narrow by symptom, brand, model, or part category.
Common DIY replacement parts include filters, remote controls, knobs, buttons, side curtains, covers, grilles, fan blades, blower wheels, brackets, power cords, and some capacitors or switches for users comfortable with safe electrical testing. Always disconnect power before opening the unit and match parts by model number. Start with air conditioner repair help and shop air conditioner capacitor parts when the symptom points to a starting problem.
For systems controlled by a wall thermostat, check the wall thermostat, WiFi thermostat, thermostat batteries, control board, incoming power, transformer, and thermostat wiring. If the thermostat display is dead, check replaceable batteries first. If the thermostat has power but does not send signals correctly, it may need replacement. See air conditioner wall thermostat troubleshooting for additional guidance on common problems and solutions when your wall thermostat is not working correctly or will not turn on.
Yes. Damaged thermostat wiring can stop the thermostat from sending signals to indoor or outdoor components. Inspect for loose connections, damaged insulation, or broken wires. Thermostat wiring can be checked for power or continuity with a multimeter, but wiring repairs should follow the unit’s diagram and applicable electrical codes. It may be best for electrical wiring work to be completed by a professional HVAC technician or electrician.
The fan motor should run when the compressor is on. If the compressor runs but the fan does not, check the fan motor, fan motor capacitor, dual run capacitor, condenser fan motor, blower motor, or selector switch. A non-running fan can cause overheating, poor cooling, and frozen coils.
If the fan runs but the compressor does not, check the temperature control thermostat, temperature control board, compressor overload, run capacitor, dual run capacitor, start relay, selector switch, thermistor, relay board, main control board, and compressor. Test the more common electrical parts before assuming the compressor itself has failed.
Yes. A selector switch directs voltage to components such as the fan motor or compressor. If the fan or compressor works intermittently when you press buttons or rotate the switch, or if you see arcing or smoke from the switch, replace the selector switch with the correct model-specific part. See air conditioner switch parts for replacement parts related to this issue.
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