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Multiple models matched. Select your model to confirm fit.

Defrost control board

Fan relay board

Control Board Kit

Furnace control board. The control board regulates the supply of power to the furnace components. Be sure to check more commonly defective parts before replacing the control board.

Temp/Fan control board

User interface board

Control-electrical

Defrost control

Furnace fan/electric heat control board.

Main control board

Control board. The control board regulates the supply of power to the furnace components. Be sure to check more commonly defective parts before replacing the control board.

Power control board

User Interface Board Kit

Defrost board

Main board
Your AC's control board is the brain of the system—when it fails, your unit won't cycle, won't respond to temperature changes, or won't power on at all. We stock genuine replacement circuit boards and timer boards for many major brands. A faulty board often shows no obvious damage, but telltale signs include the compressor not running, the fan staying on constantly, or the system ignoring thermostat commands.
Finding the exact board match matters because control boards are model-specific. That's why we make it easy to identify your part by entering your air conditioner model number—it takes 30 seconds and ensures you get the right board the first time. Browse our Air Conditioner Circuit Board Timer Parts selection or use our parts finder.
A dead or failing circuit board is one of the toughest AC problems to diagnose yourself—there are no obvious leaks or strange sounds, just silence or erratic behavior. Below are real scenarios Repair Clinic customers face and how to tell if your board needs replacement.
If your unit's indoor blower runs but the compressor never kicks in, and you hear a steady hum from the outdoor unit, the problem is usually a bad contactor or relay on the control board. The board is sending voltage to energize the compressor, but the relay contact is stuck open. Test by listening for a audible click from the outdoor disconnect when the thermostat calls for cooling. No click = board issue. Our genuine boards come with all relays and contactors pre-installed, ready to swap in.
Your model number is on the rating plate, typically found on the back or side of the outdoor condenser unit (for central AC) or on the back panel of a window or portable unit. Write down the full model number and serial number. Enter both into our parts finder, and we'll show you the exact control board your unit needs. Don't guess—one digit off and you'll get the wrong board.
Yes. A board with failing capacitors or a malfunctioning thermistor (temperature sensor) often causes short-cycling: the AC cools for 2–3 minutes, shuts off, waits 30 seconds, then starts again. This strains the compressor and wastes energy. A replacement board with factory-fresh timing and sensor calibration will restore normal 15–20 minute cooling cycles.
They're often the same part. Your "control board" or "circuit board" handles timing, relay logic, and sensor input. Some boards have a dedicated timer chip, others integrate timing into the main logic. Repair Clinic stocks boards labeled as either—just enter your model and we'll match the exact part your AC needs.


Ordering your air conditioner circuit board timer replacement parts online is quick and easy with Repair Clinic. You can search by model number or part number to find the exact air conditioning circuit board parts you need. We offer a reliable shopping experience to make your repairs more efficient.
Take advantage of our No-Hassle 365-Day Returns, which allows you to return any uninstalled air conditioner board replacement parts within one year of purchase. Plus, our Price Match Guarantee ensures you're always getting competitive pricing on genuine, high-quality OEM parts for your AC system.
Need your parts fast? We offer same-day shipping on orders placed by 9:00 PM ET, so you'll receive your air conditioner circuit board replacement parts promptly and can get back to maintaining your unit with minimal delay.
Whether you're a homeowner handling DIY repairs or a professional HVAC technician, Repair Clinic is here to support you. Our extensive resources, including expert guides and customer service, are available to assist you in troubleshooting and replacing your air conditioner control board or other parts.
Check the exterior nameplate on your central air conditioner's condenser, or look behind the front grille of a window unit for its model number. Portable models usually list it on the side or back cabinet, while some units place the label inside an access panel. Copy the complete model number exactly, including letters and numbers, then enter it in the search bar to filter the full air conditioner parts catalog to parts that fit your unit. This model-based lookup applies across every associated part category, not just circuit boards and timers. It is the quickest way to be sure the part fits before you order.

Repair Clinic's online repair library is where Air Conditioner owners and technicians go to diagnose the problem and complete the fix. Video walkthroughs, symptom articles, part testing tutorials, and exploded-view diagrams cover the most common repairs from start to finish. Model number lookup confirms the exact OEM part before you order.

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