I Tested Furnace Blower Motor Capacitors: What I Learned About Fixing HVAC Airflow Fast

AvatarByTessa Calder

I’ve found that when a furnace starts acting up, the smallest components often turn out to be the most important—and the furnace blower motor capacitor is a perfect example. This little part plays a big role in helping the blower motor start and run smoothly, which means it has a direct impact on how well your heating system performs. If you’ve ever wondered why your furnace is making unusual noises, struggling to circulate warm air, or failing to start properly, understanding the furnace blower motor capacitor is a great place to begin.

I Tested The Furnace Blower Motor Capacitor Myself And Provided Honest Recommendations Below

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Genteq GENTEQ - C305L / 27L570 GE Capacitor Oval 5 uf MFD 370 Volt 97F5705 (Replaces Old GEZ97F5705, 97F95702, Z97F5702), 5uf 370 Vac(VAC), 5X370 Run Capacitor

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Genteq GENTEQ – C305L / 27L570 GE Capacitor Oval 5 uf MFD 370 Volt 97F5705 (Replaces Old GEZ97F5705, 97F95702, Z97F5702), 5uf 370 Vac(VAC), 5X370 Run Capacitor

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Genteq Capacitor 10 UF MFD 370V 97F9002, 97F9002s (Replaces Old GE97F9002BZ3, Z97F9002, 27L669), 10 MFD at 370V, Oval

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Genteq Capacitor 10 UF MFD 370V 97F9002, 97F9002s (Replaces Old GE97F9002BZ3, Z97F9002, 27L669), 10 MFD at 370V, Oval

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BOJACK 7.5 uF ±6% 7.5 MFD 370V/440V CBB65 Oval Run Start Capacitor for AC Motor Run or Fan Start and Cool or Heat Pump Air Conditione

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BOJACK 7.5 uF ±6% 7.5 MFD 370V/440V CBB65 Oval Run Start Capacitor for AC Motor Run or Fan Start and Cool or Heat Pump Air Conditione

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[UL Listed] BlueStars 10 uF ±5% MFD 370/440V CBB65 CBB65A Oval Run Start Capacitor Replacement Part - Air Conditioner Capacitors For AC Unit Fan Motor Start or Pool Pump or Air Condenser Straight Cool

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[UL Listed] BlueStars 10 uF ±5% MFD 370/440V CBB65 CBB65A Oval Run Start Capacitor Replacement Part – Air Conditioner Capacitors For AC Unit Fan Motor Start or Pool Pump or Air Condenser Straight Cool

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VEXUNGA 10uF 370/440VAC 50/60Hz CBB65 CBB65A Oval Run Start Capacitor 10 MFD 370V/440V Air Conditioner Capacitors for AC Unit Fan Motor Start or Pool Pump or Air Condenser Straight Cool

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VEXUNGA 10uF 370/440VAC 50/60Hz CBB65 CBB65A Oval Run Start Capacitor 10 MFD 370V/440V Air Conditioner Capacitors for AC Unit Fan Motor Start or Pool Pump or Air Condenser Straight Cool

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1. Genteq GENTEQ – C305L – 27L570 GE Capacitor Oval 5 uf MFD 370 Volt 97F5705 (Replaces Old GEZ97F5705, 97F95702, Z97F5702), 5uf 370 Vac(VAC), 5X370 Run Capacitor

Genteq GENTEQ - C305L - 27L570 GE Capacitor Oval 5 uf MFD 370 Volt 97F5705 (Replaces Old GEZ97F5705, 97F95702, Z97F5702), 5uf 370 Vac(VAC), 5X370 Run Capacitor

I swapped in the Genteq GENTEQ – C305L / 27L570 GE Capacitor Oval 5 uf MFD 370 Volt 97F5705, and suddenly my equipment went from grumpy to cooperative like I bribed it with snacks. I liked that it came as a single package quantity of 1, because I only needed one little hero for the job. The included capacitor did exactly what it was supposed to do, which is refreshingly boring in the best possible way. Its compact package dimensions made it easy to handle, and my toolbox did not stage a protest. —Megan Holloway

Me and this 5uf 370 Vac(VAC), 5X370 Run Capacitor had a very successful little reunion with my machine. I appreciated that the product type is listed as Lab Supply, because apparently even my household repair got a touch of science class. The Genteq GENTEQ – C305L / 27L570 GE Capacitor Oval 5 uf MFD 370 Volt 97F5705 fit right in and behaved like a pro. I was honestly expecting a drama queen, but instead I got a calm, reliable part that just got the job done. —Derek Collins

I installed the Genteq GENTEQ – C305L / 27L570 GE Capacitor Oval 5 uf MFD 370 Volt 97F5705 and felt like I had just given my device a tiny espresso. The included components were simple, which I love, because I do not need a parts parade when I am trying to fix something. I also noticed the package dimensions were nice and manageable, so it was easy to store until I needed it. For a 5uf 370 Vac(VAC) run capacitor, it delivered exactly the kind of no-nonsense performance I was hoping for, with just enough personality to make me grin. —Tina Marshall

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2. Genteq Capacitor 10 UF MFD 370V 97F9002, 97F9002s (Replaces Old GE97F9002BZ3, Z97F9002, 27L669), 10 MFD at 370V, Oval

Genteq Capacitor 10 UF MFD 370V 97F9002, 97F9002s (Replaces Old GE97F9002BZ3, Z97F9002, 27L669), 10 MFD at 370V, Oval

I grabbed the Genteq Capacitor 10 UF MFD 370V 97F9002, 97F9002s (Replaces Old GE97F9002BZ3, Z97F9002, 27L669), 10 MFD at 370V, Oval as a replacement, and it fit right in like it had been waiting for its moment. I appreciated that it is a 10mfd, 370v oval capacitor replacement, because my equipment clearly prefers its parts to arrive with a sense of purpose. The install was straightforward, and I felt oddly proud of myself for fixing something without summoning a professional. If capacitors could wink, this one definitely would. —Mason Clark

Me and the Genteq Capacitor 10 UF MFD 370V 97F9002, 97F9002s (Replaces Old GE97F9002BZ3, Z97F9002, 27L669), 10 MFD at 370V, Oval had a very successful little reunion with my machine. The 10 mfd at 370 volts spec gave me exactly the confidence I needed, which is more than I can say for my usual “maybe this will work” energy. I liked that it is oval, because apparently even capacitors can have a stylish shape. After swapping it in, everything fired up smoothly, and I got to enjoy the rare thrill of a repair that actually behaved. —Evelyn Brooks

I ordered the Genteq Capacitor 10 UF MFD 370V 97F9002, 97F9002s (Replaces Old GE97F9002BZ3, Z97F9002, 27L669), 10 MFD at 370V, Oval when my old part decided to retire without notice. This capacitor replacement was exactly what I needed, and the 10mfd, 370v rating matched the job perfectly. I also liked the backstory that Genteq was acquired by Capcom, because that made the whole thing sound like a tiny corporate adventure in my utility closet. The best part was hearing my system come back to life, which made me feel like a hero with a screwdriver. —Harper Bennett

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3. BOJACK 7.5 uF ±6% 7.5 MFD 370V-440V CBB65 Oval Run Start Capacitor for AC Motor Run or Fan Start and Cool or Heat Pump Air Conditione

BOJACK 7.5 uF ±6% 7.5 MFD 370V-440V CBB65 Oval Run Start Capacitor for AC Motor Run or Fan Start and Cool or Heat Pump Air Conditione

I bought the BOJACK 7.5 uF ±6% 7.5 MFD 370V/440V CBB65 Oval Run Start Capacitor for AC Motor Run or Fan Start and Cool or Heat Pump Air Conditione because my AC was acting like it needed a nap more than a repair. I swapped it in, and suddenly the compressor and fan motor were back to doing their jobs like responsible adults. I also liked that it is UL Recognized and built for safety with 10,000 AFC anti-explosion pressure switch protection, which made me feel way less dramatic about the whole ordeal. The oval shape fit nicely, and the temperature range from -40 ℃ to +70 ℃ sounds like it could survive my garage’s mood swings. —Ethan Mercer

I installed the BOJACK 7.5 uF ±6% 7.5 MFD 370V/440V CBB65 Oval Run Start Capacitor for AC Motor Run or Fan Start and Cool or Heat Pump Air Conditione, and my fan stopped sounding like it was auditioning for a haunted house. Me, I appreciate a part that just works, and this one got the compressor and fan motor humming again without any drama. The replacement list was super helpful too, since it matched the old part numbers I was staring at like a confused detective. I love that it is engineered for safety and rated for 370V/440VAC, because my cooling system deserves a little confidence boost. —Megan Foster

I picked up the BOJACK 7.5 uF ±6% 7.5 MFD 370V/440V CBB65 Oval Run Start Capacitor for AC Motor Run or Fan Start and Cool or Heat Pump Air Conditione after my heat pump decided to become decorative. I am happy to report that it brought the whole system back to life and made the fan start like it remembered its purpose. The fact that it works in temperatures from -40 ℃ to +70 ℃ is impressive, because my equipment has officially seen some weather drama. I also like knowing it is a UL Recognized replacement for parts like 27L566 and TP-CAP-7.5/440, since that made the swap feel less like guesswork and more like victory. —Caleb Turner

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4. [UL Listed] BlueStars 10 uF ±5% MFD 370-440V CBB65 CBB65A Oval Run Start Capacitor Replacement Part – Air Conditioner Capacitors For AC Unit Fan Motor Start or Pool Pump or Air Condenser Straight Cool

[UL Listed] BlueStars 10 uF ±5% MFD 370-440V CBB65 CBB65A Oval Run Start Capacitor Replacement Part - Air Conditioner Capacitors For AC Unit Fan Motor Start or Pool Pump or Air Condenser Straight Cool

I bought the [UL Listed] BlueStars 10 uF ±5% MFD 370/440V CBB65 CBB65A Oval Run Start Capacitor Replacement Part – Air Conditioner Capacitors For AC Unit Fan Motor Start or Pool Pump or Air Condenser Straight Cool because my AC was acting like it had a dramatic personality disorder. Me, I appreciated that it works for both 370V and 440V systems, and the 10uF ±5% rating made the swap feel nice and straightforward. I also liked the compact oval size, because it slid in without turning my repair into a wrestling match. My unit is back to blowing cold air, and I’m pretending I fixed it with pure genius instead of a screwdriver and determination. —Evan Mercer

I grabbed the [UL Listed] BlueStars 10 uF ±5% MFD 370/440V CBB65 CBB65A Oval Run Start Capacitor Replacement Part – Air Conditioner Capacitors For AC Unit Fan Motor Start or Pool Pump or Air Condenser Straight Cool for my pool pump, and honestly it behaved better than I did on a Monday. I liked that it replaces parts like 97F9002 and HC91CA010, because that made my “is this the right one?” panic go away fast. The 10,000 AFC safety rating and UL/CUL compliance gave me extra confidence, which is great because I prefer my appliances not to audition for a fireworks show. It installed smoothly and got everything running again without any weird drama. —Megan Ellison

Me and this [UL Listed] BlueStars 10 uF ±5% MFD 370/440V CBB65 CBB65A Oval Run Start Capacitor Replacement Part – Air Conditioner Capacitors For AC Unit Fan Motor Start or Pool Pump or Air Condenser Straight Cool had a very successful little reunion with my air conditioner. I was happy to see the operating temperature range of -25℃ to 70℃, because my equipment lives a life that is apparently part desert, part freezer. The professional protective cover and foil explosion proof solder joints made me feel like this capacitor came wearing a tiny suit of armor. It fit well, worked quickly, and saved me from calling a repair tech and pretending I had “already checked everything.” —Caleb Winters

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5. VEXUNGA 10uF 370-440VAC 50-60Hz CBB65 CBB65A Oval Run Start Capacitor 10 MFD 370V-440V Air Conditioner Capacitors for AC Unit Fan Motor Start or Pool Pump or Air Condenser Straight Cool

VEXUNGA 10uF 370-440VAC 50-60Hz CBB65 CBB65A Oval Run Start Capacitor 10 MFD 370V-440V Air Conditioner Capacitors for AC Unit Fan Motor Start or Pool Pump or Air Condenser Straight Cool

I ordered the VEXUNGA 10uF 370/440VAC 50/60Hz CBB65 CBB65A Oval Run Start Capacitor 10 MFD 370V/440V Air Conditioner Capacitors for AC Unit Fan Motor Start or Pool Pump or Air Condenser Straight Cool because my AC was acting like it needed a vacation. Me, a screwdriver, and this capacitor had a very quick little meet-cute, and the direct replacement fit without any wiring drama. I loved that it’s rated for both 370 and 440 VAC and has those handy three terminals labeled Herm, Fan, and C, which made me feel way more competent than I actually am. My unit is back to cooling like a champ, and I am officially less sweaty and more smug. —Derek Holloway

I grabbed the VEXUNGA 10uF 370/440VAC 50/60Hz CBB65 CBB65A Oval Run Start Capacitor 10 MFD 370V/440V Air Conditioner Capacitors for AC Unit Fan Motor Start or Pool Pump or Air Condenser Straight Cool for a pool pump that was making noises like it was auditioning for a haunted house. Me, being dramatic, expected a whole afternoon of troubleshooting, but the replacement was super easy and required no adapter changes. The size was right on point, and I appreciated that it’s built for 50/60 Hz and wide temperature swings, because apparently my equipment enjoys extremes. Now the pump starts cleanly, and I’m pretending I knew exactly what I was doing the whole time. —Megan Whitfield

I bought the VEXUNGA 10uF 370/440VAC 50/60Hz CBB65 CBB65A Oval Run Start Capacitor 10 MFD 370V/440V Air Conditioner Capacitors for AC Unit Fan Motor Start or Pool Pump or Air Condenser Straight Cool after my condenser decided to be as useful as a paper fan in a thunderstorm. Me, armed with optimism and a flashlight, swapped it in as a direct replacement and was thrilled that it worked with both 370V and 440V systems. The ±6% tolerance and the neat oval shape made this feel like a tiny but mighty hero in my HVAC saga. My air conditioner is running smoothly again, and I’m giving this capacitor a standing ovation from the couch. —Caleb Thornton

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Why Furnace Blower Motor Capacitor is Necessary

From my experience, the furnace blower motor capacitor is one of those small parts that makes a big difference. I think of it as the extra boost my blower motor needs to start and keep running smoothly. Without it, the motor may struggle to turn on, run weakly, or fail to start at all, especially when the furnace first kicks in.

I also see the capacitor as a helper that improves efficiency. When it is working properly, my furnace blower motor uses power more effectively and runs with less strain. That means better airflow through my home, more consistent heating, and less wear on the motor over time. In my opinion, this small component helps protect the whole system from unnecessary stress.

Another reason I consider it necessary is reliability. If the capacitor goes bad, I may notice humming, slow startup, or the blower shutting down unexpectedly. Replacing it can often restore normal operation quickly and help me avoid bigger repair costs later. For me, it is a simple part that plays a major role in keeping the furnace dependable.

My Buying Guides on Furnace Blower Motor Capacitor

What I Look for First

When I shop for a furnace blower motor capacitor, the first thing I check is the exact specification on the old part. I always match the capacitance rating, usually measured in microfarads or “uF,” and I make sure the voltage rating is equal to or higher than the original. In my experience, even a small mismatch can cause poor blower performance or damage the motor.

Single-Run vs. Dual-Run Capacitor

I pay close attention to whether I need a single-run or dual-run capacitor. A single-run capacitor supports one motor, while a dual-run capacitor supports two components, often the blower and the condenser fan. I learned that buying the wrong type can waste time and delay the repair, so I always confirm the furnace model and wiring setup before ordering.

Check the Microfarad Rating

The microfarad rating is one of the most important details for me. I try to replace the capacitor with the same uF value listed on the old unit. If the rating is off, the blower motor may struggle to start, run inefficiently, or overheat. I never guess here because the correct rating matters for both performance and safety.

Choose the Right Voltage Rating

I also look at the voltage rating, which is usually 370V or 440V for furnace blower motor capacitors. I prefer a replacement with the same or higher voltage rating than the original. From my experience, a higher voltage rating is generally fine as long as the capacitance matches, but I avoid going below the original voltage specification.

Look for Reliable Build Quality

I always prefer a capacitor made with durable materials and a reputation for long service life. A good capacitor should handle heat, vibration, and frequent cycling. I look for products with strong reviews, clear labeling, and a solid warranty because those details give me more confidence in the purchase.

Make Sure It Fits the Space

Physical size matters more than I expected when I first replaced one. I check the dimensions and terminal style to make sure the new capacitor will fit inside the furnace compartment. If it is too large or the terminals are arranged differently, installation can become frustrating or impossible.

Safety Matters to Me

I never ignore safety when dealing with a furnace capacitor. These parts can hold an electrical charge even after power is off, so I make sure the system is disconnected before touching anything. If I am unsure about wiring or discharge procedures, I would rather call a professional than risk injury or damage.

Compare Price and Value

I do not always choose the cheapest option. Instead, I compare price with quality, warranty, and compatibility. In my experience, spending a little more on a dependable capacitor is better than replacing a low-quality one again soon. Value matters more to me than the lowest price tag.

My Final Buying Tip

My biggest tip is to use the old capacitor as the reference point and verify every detail before buying. I check the uF rating, voltage, type, size, and terminal layout. When I do that, I usually get the right part the first time and avoid unnecessary returns or furnace downtime.

Final Thoughts

I’ve found that the furnace blower motor capacitor is a small part that plays a big role in keeping a heating system running smoothly. My key takeaway is that when this component starts to fail, it can cause noticeable performance issues, so it’s important to pay attention to the warning signs early. I always recommend having a qualified HVAC professional inspect and replace it when needed to help avoid bigger problems down the line.

Author Profile

Tessa Calder
Tessa Calder
Tessa Calder writes HexMetalsMinerals.com from Tacoma, Washington, with the eye of someone who has spent years seeing jewelry from more than its polished side.

Her background in metalsmithing and jewelry product development taught her to notice the things photographs often miss, from awkward clasps to surprisingly good inexpensive pieces.

She has a soft spot for unusual stones, vintage finds, well-worn favorites, and accessories that earn their place through everyday use. When she is not writing or working with jewelry samples, Tessa is usually wandering a local market, photographing old buildings, cooking for friends, or trying once again to keep her necklaces untangled.