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You need Contactor HN51KC024 if you're having trouble with the compressor or fan motor on your air conditioner, furnace, heat pump, or air handler. This genuine OEM single-pole, 24-volt coil contactor has a full load amps (FLA) rating of 30 amps and a locked rotor amps (LRA) rating of 150 amps.

Contactor, 2 pole, 30 amp, 24 vac **Special Note** This may replace single pole contactor and require a technican to install (based on model #)

Contactor, 25 amp, 1-pole, 24 vac 60/50 hz coil

Contactor with shunt, 1 pole, 30 amps, 24 volts

Fan relay, 24v coil, 50-60hz, spst-no/nc

Contactor 24 volt coil, 30 FLA, Two Pole

Contactor, 24 volts, 30 amps, 1pole

Safety float switch

Pressure Switch, 2 stage

Pressure Switch

Rollout switch, 210f

Switch-interlock

Contactor, 24V, 2 pole, 40 Amp

Fan rly dpdt, 24 vac coil

Pressure switch -.65" wc spst 1/4" barb connection
Air conditioner switches—including contactors, thermostats, selector switches, and power switches—are the backbone of your cooling system's electrical control. When your unit won't power on, won't respond to thermostat changes, or cycles erratically, a faulty switch is often the problem. These switches handle high electrical loads and wear out over time, especially in units running during peak summer heat.
We stock genuine replacement switches for, and every other major brand in our catalog. Browse our air conditioner switch parts to find the exact contactor, selector, or thermostat switch your model requires.
Find your part: Enter your air conditioner model number above to locate the correct switch assembly.
Switches control everything from power delivery to temperature sensing. Here's what you need to know.
A contactor is an electrical relay that turns the compressor and condenser fan motor on and off based on signals from your thermostat. A selector switch lets you choose between cooling, heating (if available), and off modes. Both can fail independently, but a faulty contactor is more likely to prevent your AC from starting entirely.
Listen for a clicking sound when you adjust the thermostat—this indicates the contactor is trying to engage. If you hear repeated clicking with no compressor start, the contactor coil is weak or the contacts are burned. A humming unit that won't cool suggests a stuck selector switch preventing the compressor from receiving power. Visual inspection may show pitting or burned contacts inside the switch housing.
While some switches share similar specifications across brands, most air conditioners use model-specific or brand-specific switch assemblies with unique mounting brackets, voltage ratings, and connector types. Installing a wrong switch can cause electrical damage or complete system failure. Always match your replacement to your exact model number and part specification.
Switch replacement often involves working with high-voltage circuits, which carries real electrical hazard. If you're experienced with AC repair and comfortable working with 240V systems, you can attempt it—but most homeowners should hire a licensed HVAC technician. The cost of professional service is worth the safety and model-specific fit and performance you gain.


Ensure your air conditioner's reliable operation with genuine switch replacement parts. Whether you're a homeowner or a professional technician, ordering air conditioner switch parts online is simple and convenient. Use our model number or part number lookup to quickly find the exact replacement you need. Plus, Our same-day shipping ensures you get your parts fast, minimizing any downtime. For more repair guidance, visit our Air Conditioner Repair Help page. Find reliable switch replacements and other Air Conditioner parts to keep your cooling system running smoothly.
Skip the guesswork on fit by starting with your air conditioner's model number, usually printed on the exterior nameplate on the condenser. If it's not there, check the side of the cabinet or look inside the access panel, where the equipment label may also list the model and serial numbers. Record the model number exactly, including letters, numbers, and dashes. Enter it in the search bar to filter this page to the parts that fit your model. The model number applies to the entire air conditioner, so it narrows the catalog across all associated part categories. That means fewer wrong orders and a faster repair.

Whether you are new to appliance repair or a seasoned technician, Air Conditioner repairs go smoother with the right online resources. Troubleshooting videos, common-symptom articles, part testing guides, and wiring diagrams cover the diagnostic and installation steps. Use the model number lookup to confirm the exact OEM part for your unit, then follow the matching video from start to finish.

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