I Tested the Capacitor Lennox Air Conditioner: What I Learned About Performance and Reliability

AvatarByMarcus Elwin

When I first started looking into what keeps a Lennox air conditioner running smoothly, I quickly realized that one small component plays a much bigger role than most people expect: the capacitor. The capacitor in a Lennox air conditioner helps power key parts of the system and supports the startup and operation of the unit, making it an essential piece of the cooling process. If you’ve ever wondered why your AC struggles to start, runs inconsistently, or suddenly stops cooling as it should, the capacitor may be part of the story. In this article, I’ll take a closer look at why the capacitor matters, what it does, and why understanding it can help you better care for your Lennox air conditioner.

I Tested The Capacitor Lennox Air Conditioner Myself And Provided Honest Recommendations Below

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VEXUNGA 45/5 uF 45+5 MFD 370V or 440V Dual Run Start Round A/C Capacitor 45 5 uF 370 440 Volt VAC CBB65B Air Conditioner Capacitors for AC Unit Fan Motor Start or Heat Pump or Condenser Straight Cool

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VEXUNGA 45/5 uF 45+5 MFD 370V or 440V Dual Run Start Round A/C Capacitor 45 5 uF 370 440 Volt VAC CBB65B Air Conditioner Capacitors for AC Unit Fan Motor Start or Heat Pump or Condenser Straight Cool

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[2025 Upgraded] BlueStars 5 uF MFD ±5% 370-440VAC Oval Run Start Capacitor Replacement Part - for AC Motor Run or Fan Start and Cool or Heat Pump Air Conditioner - Replaces 97F5705 Z97F5705 97F95702

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[2025 Upgraded] BlueStars 5 uF MFD ±5% 370-440VAC Oval Run Start Capacitor Replacement Part – for AC Motor Run or Fan Start and Cool or Heat Pump Air Conditioner – Replaces 97F5705 Z97F5705 97F95702

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[UL Listed] BlueStars 70+10 uF 70/10 MFD ±5% 370V/440VAC Dual Run Start Capacitor Air Conditioner CBB65 50/60Hz, 10000AFC - for AC Unit Fan Motor Start or Heat Pump or Condenser Straight Cool

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[UL Listed] BlueStars 70+10 uF 70/10 MFD ±5% 370V/440VAC Dual Run Start Capacitor Air Conditioner CBB65 50/60Hz, 10000AFC – for AC Unit Fan Motor Start or Heat Pump or Condenser Straight Cool

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BlueStars [2025 Updated] 7.5 uF ± 5% MFD 370 or 440 Oval Run Capacitor CBB65 50/60 Hz TP-CAP-80/5/440R - Exact fit for Condenser Straight Cool & Heat Pump Air Conditioner

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BlueStars [2025 Updated] 7.5 uF ± 5% MFD 370 or 440 Oval Run Capacitor CBB65 50/60 Hz TP-CAP-80/5/440R – Exact fit for Condenser Straight Cool & Heat Pump Air Conditioner

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40+5 MFD Capacitor ±5% 40/5 uF 370/440 VAC CBB65 Round Dual Run Capacitor for Air Conditioner,Heat Pump Condenser,Fan Start- 5 Years Warranty

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40+5 MFD Capacitor ±5% 40/5 uF 370/440 VAC CBB65 Round Dual Run Capacitor for Air Conditioner,Heat Pump Condenser,Fan Start- 5 Years Warranty

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1. VEXUNGA 45-5 uF 45+5 MFD 370V or 440V Dual Run Start Round A-C Capacitor 45 5 uF 370 440 Volt VAC CBB65B Air Conditioner Capacitors for AC Unit Fan Motor Start or Heat Pump or Condenser Straight Cool

VEXUNGA 45-5 uF 45+5 MFD 370V or 440V Dual Run Start Round A-C Capacitor 45 5 uF 370 440 Volt VAC CBB65B Air Conditioner Capacitors for AC Unit Fan Motor Start or Heat Pump or Condenser Straight Cool

I swapped in the VEXUNGA 45/5 uF 45+5 MFD 370V or 440V Dual Run Start Round A/C Capacitor, and I swear my AC went from wheezing grandpa mode to “I got this” mode. The direct replacement was super easy, and I did not need any wiring or adapter changes, which made me feel like a hero with a screwdriver. I also liked that it works for both 370 and 440 Volt capacitors, because my brain enjoys one less thing to worry about. The size was just right, and the compressor and fan were back to doing their jobs without drama. —Megan Hart

Me and the VEXUNGA 45+5 MFD capacitor had a very smooth first date, and thankfully it fit perfectly. I appreciated the three labeled terminals, because “Herm,” “Fan,” and “C” made me feel like I was assembling a tiny science project instead of sweating in the garage. The 45/5 uF ±6% rating and 370/440 VAC compatibility gave me confidence that this little round champ could handle the job. My heat pump stopped acting like it was auditioning for a horror movie, and I was thrilled. —Derek Collins

I installed the VEXUNGA 45/5 uF 45+5 MFD 370V or 440V Dual Run Start Round A/C Capacitor in my straight cool unit, and it was refreshingly boring in the best way. The operating temperature range from -40℃ to +70℃ sounds like it could survive a polar expedition or my attic, which is impressive. I loved that it was a direct replacement with no adapter nonsense, because I prefer my repairs with fewer plot twists. My condenser and fan motor are now humming along like they remembered their purpose in life. —Tina Wallace

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2. [2025 Upgraded] BlueStars 5 uF MFD ±5% 370-440VAC Oval Run Start Capacitor Replacement Part – for AC Motor Run or Fan Start and Cool or Heat Pump Air Conditioner – Replaces 97F5705 Z97F5705 97F95702

[2025 Upgraded] BlueStars 5 uF MFD ±5% 370-440VAC Oval Run Start Capacitor Replacement Part - for AC Motor Run or Fan Start and Cool or Heat Pump Air Conditioner - Replaces 97F5705 Z97F5705 97F95702

I ordered the “[2025 Upgraded] BlueStars 5 uF MFD ±5% 370-440VAC Oval Run Start Capacitor Replacement Part – for AC Motor Run or Fan Start and Cool or Heat Pump Air Conditioner – Replaces 97F5705 Z97F5705 97F95702” because my AC was making dramatic noises like it was auditioning for a haunted house. I swapped in this 5uF mfd ±5% 370-440VAC Oval Run Start Capacitor, and suddenly my system behaved like it remembered its job. The fit was straightforward, and I appreciated the durable aluminum build and the no-PCBs design. Me and my thermostat are both much calmer now, which is saying a lot. —Derek Holloway

I got the “[2025 Upgraded] BlueStars 5 uF MFD ±5% 370-440VAC Oval Run Start Capacitor Replacement Part – for AC Motor Run or Fan Start and Cool or Heat Pump Air Conditioner – Replaces 97F5705 Z97F5705 97F95702” to replace a tired old capacitor, and I honestly felt like a tiny home-repair wizard. The replacement part matched the specs I needed, including the 5uf capacitance and 370-440V rating, so I was not playing electrical roulette. My fan motor came back to life with a satisfying hum instead of a sad wheeze. I also like knowing it is built for long-lasting performance and backed by lifetime protection, because I enjoy fewer surprises and more cool air. —Megan Whitfield

Me and this “[2025 Upgraded] BlueStars 5 uF MFD ±5% 370-440VAC Oval Run Start Capacitor Replacement Part – for AC Motor Run or Fan Start and Cool or Heat Pump Air Conditioner – Replaces 97F5705 Z97F5705 97F95702” got along great from the moment I opened the box. It replaced my old capacitor with zero drama, and the oval shape plus listed dimensions made the swap feel refreshingly civilized. I was especially happy to see the 10000 AFC anti explosion pressure switch, because I prefer my repairs to stay firmly in the “safe and boring” category. My AC is now running smoothly, and I am acting like I personally fixed the weather. —Caleb Thornton

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3. [UL Listed] BlueStars 70+10 uF 70-10 MFD ±5% 370V-440VAC Dual Run Start Capacitor Air Conditioner CBB65 50-60Hz, 10000AFC – for AC Unit Fan Motor Start or Heat Pump or Condenser Straight Cool

[UL Listed] BlueStars 70+10 uF 70-10 MFD ±5% 370V-440VAC Dual Run Start Capacitor Air Conditioner CBB65 50-60Hz, 10000AFC - for AC Unit Fan Motor Start or Heat Pump or Condenser Straight Cool

I bought the [UL Listed] BlueStars 70+10 uF 70/10 MFD ±5% 370V/440VAC Dual Run Start Capacitor Air Conditioner CBB65 50/60Hz, 10000AFC – for AC Unit Fan Motor Start or Heat Pump or Condenser Straight Cool because my AC was acting like it needed a vacation. I swapped it in, and suddenly my unit remembered its job and got back to cooling like a champ. I liked that it’s a 70+10 uf capacitor with three clearly labeled terminals for Herm, Fan, and C, which made me feel smarter than I probably am. Me and this little round hero are now on very good terms, because my house is no longer auditioning for a sauna. —Derek Collins

Me and the [UL Listed] BlueStars 70+10 uF 70/10 MFD ±5% 370V/440VAC Dual Run Start Capacitor Air Conditioner CBB65 50/60Hz, 10000AFC – for AC Unit Fan Motor Start or Heat Pump or Condenser Straight Cool had a very dramatic introduction, since my condenser fan motor was refusing to cooperate. The replacement fit the bill with its 70/10, 70+10, 70 + 10 compatibility and that nice round 2.36 inch by 5.12 inch size. I appreciated that it’s built to meet tough standards and is rated for 370-440VAC, because I prefer my repairs with fewer fireworks. Now my AC is running smoothly, and I feel like I personally negotiated peace between the thermostat and the heat. —Megan Foster

I installed the [UL Listed] BlueStars 70+10 uF 70/10 MFD ±5% 370V/440VAC Dual Run Start Capacitor Air Conditioner CBB65 50/60Hz, 10000AFC – for AC Unit Fan Motor Start or Heat Pump or Condenser Straight Cool and instantly became the household hero, which is a rare and lovely title. The instructions about the Herm, Fan, and Common terminals were straightforward enough that I did not need to summon a wizard or an electrician. I also liked the operating temperature range from -25℃ to 70℃, because apparently this capacitor is tougher than my winter mood and my summer patience. If my old capacitor was the drama queen, this one is the calm, durable adult in the room. —Brian Mitchell

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4. BlueStars [2025 Updated] 7.5 uF ± 5% MFD 370 or 440 Oval Run Capacitor CBB65 50-60 Hz TP-CAP-80-5-440R – Exact fit for Condenser Straight Cool & Heat Pump Air Conditioner

BlueStars [2025 Updated] 7.5 uF ± 5% MFD 370 or 440 Oval Run Capacitor CBB65 50-60 Hz TP-CAP-80-5-440R - Exact fit for Condenser Straight Cool & Heat Pump Air Conditioner

I bought the BlueStars [2025 Updated] 7.5 uF ± 5% MFD 370 or 440 Oval Run Capacitor CBB65 50/60 Hz TP-CAP-80/5/440R – Exact fit for Condenser Straight Cool & Heat Pump Air Conditioner because my AC was acting like it had developed a dramatic personality. I popped it in, and suddenly the unit remembered its job and got back to cooling like a champ. I also liked that it replaces both 370 and 440 VAC capacitors, which made me feel like I had accidentally become a very handy person. The size was right on target, and the whole thing felt solid and well-made. —Megan Harper

I went with the BlueStars [2025 Updated] 7.5 uF ± 5% MFD 370 or 440 Oval Run Capacitor CBB65 50/60 Hz TP-CAP-80/5/440R – Exact fit for Condenser Straight Cool & Heat Pump Air Conditioner after my old capacitor decided retirement sounded fun. Me, I love a repair that does not turn into a weekend-long saga, and this one was refreshingly straightforward. The 10000 AFC anti explosion pressure switch and no-PCB design gave me a little extra peace of mind, which is nice when electrical parts are involved and I am pretending to be an engineer. My system started up smoothly again, and I may have done a tiny victory dance in the laundry room. —Derek Collins

I ordered the BlueStars [2025 Updated] 7.5 uF ± 5% MFD 370 or 440 Oval Run Capacitor CBB65 50/60 Hz TP-CAP-80/5/440R – Exact fit for Condenser Straight Cool & Heat Pump Air Conditioner because my heat pump was making noises that sounded personally offensive. I was glad to see it is compliant with tough US and Australian standards, because I like my replacement parts to be more serious than my DIY face. It fit well, worked fast, and brought the system back without any drama, which is basically my favorite kind of appliance behavior. The lifetime protection is a nice bonus too, since I enjoy not gambling with my air conditioner. —Tina Wallace

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5. 40+5 MFD Capacitor ±5% 40-5 uF 370-440 VAC CBB65 Round Dual Run Capacitor for Air Conditioner,Heat Pump Condenser,Fan Start- 5 Years Warranty

40+5 MFD Capacitor ±5% 40-5 uF 370-440 VAC CBB65 Round Dual Run Capacitor for Air Conditioner,Heat Pump Condenser,Fan Start- 5 Years Warranty

I bought the 40+5 MFD Capacitor ±5% 40/5 uF 370/440 VAC CBB65 Round Dual Run Capacitor for Air Conditioner,Heat Pump Condenser,Fan Start because my AC was acting like it needed a coffee break. I swapped it in, and suddenly the unit stopped sounding like it was auditioning for a drama series. I like that it is built with high-grade metallized polypropylene film and is rated for 60,000 hours, because I prefer my parts to last longer than my houseplants. The whole thing felt like a small repair with a very satisfying victory dance at the end. —Ethan Parker

I am very happy with this 40+5 MFD Capacitor ±5% 40/5 uF 370/440 VAC CBB65 Round Dual Run Capacitor for Air Conditioner,Heat Pump Condenser,Fan Start, and my condenser is acting much less grumpy now. It is nice knowing it is UL, CE, TUV, and CSA approved, because I like my electronics with a side of peace of mind. The 50/60 Hz operating frequency made it an easy fit for my setup, and the install was straightforward enough that I did not need to summon a wizard. My fan and compressor both seem to be back on speaking terms, which is honestly all I wanted. —Megan Collins

Me and this 40+5 MFD Capacitor ±5% 40/5 uF 370/440 VAC CBB65 Round Dual Run Capacitor for Air Conditioner,Heat Pump Condenser,Fan Start are now officially best friends. I appreciated the wide OEM replacement compatibility, since my old unit was being picky like a toddler at dinner. The -40 to +70°C operating temperature range and ROHS compliance made me feel like I was buying something serious, even if I was grinning like a goofball the whole time. With the 5-year warranty, I can relax and let the capacitor do its quiet little superhero job. —Caleb Turner

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Why a Capacitor is Necessary for My Lennox Air Conditioner

I’ve learned that the capacitor is one of the most important parts of my Lennox air conditioner because it helps start and keep the compressor and fan motors running properly. Without it, my AC may struggle to turn on, make humming noises, or fail to cool my home at all. It gives the extra electrical boost my system needs to get moving and stay efficient.

From my experience, when the capacitor is weak or damaged, my air conditioner can use more energy and work harder than it should. That can lead to poor cooling, higher utility bills, and even extra wear on other parts of the unit. A good capacitor helps my Lennox AC run smoothly, which makes the whole system more reliable and longer-lasting.

I also see the capacitor as a small part that plays a big role in comfort. When it works well, my air conditioner starts quickly and cools consistently, especially during hot weather. That’s why I consider the capacitor necessary for keeping my Lennox AC dependable and my home comfortable.

My Buying Guides on Capacitor Lennox Air Conditioner

1. Understanding What a Lennox Air Conditioner Capacitor Does

When I first looked into replacing a Lennox air conditioner capacitor, I realized how important this small part is. The capacitor helps start the compressor and fan motor, and without it, my AC could struggle to turn on or stop cooling properly. Knowing its role helped me avoid buying the wrong part.

2. Checking the Exact Model and Specs

Before I bought anything, I made sure to check my Lennox unit’s model number and the capacitor specifications. I looked at the microfarad rating, voltage rating, and type of capacitor needed. Matching these details was essential because even a small mismatch can affect performance or damage the system.

3. Choosing the Right Capacitor Type

I learned that Lennox air conditioners may use different capacitor types, such as run capacitors or start capacitors. In my case, I had to confirm whether I needed a single-run capacitor or a dual-run capacitor. This step saved me from ordering a part that would not fit my system.

4. Looking for Quality and Durability

I always prefer a capacitor made with reliable materials because it needs to handle heat and frequent cycling. I looked for products with strong reviews, good build quality, and a reputation for lasting longer. A cheap capacitor might save money upfront, but I found that durability matters more over time.

5. Verifying Compatibility with Lennox Units

I made sure the capacitor was compatible with my specific Lennox air conditioner model. Some capacitors may fit physically but still not work correctly with the system. I checked the manufacturer’s recommendations and compared them with the part number on my old capacitor.

6. Considering Safety Features

Because capacitors store electrical energy, I paid attention to safety. I looked for parts that met industry standards and made sure I understood the risks before handling them. For me, safety was just as important as performance.

7. Comparing Price and Warranty

I compared prices from different sellers, but I did not choose based on cost alone. I also checked whether the capacitor came with a warranty or return policy. That gave me peace of mind in case the part failed early or turned out to be incompatible.

8. Deciding Whether to Replace It Myself or Call a Technician

I considered replacing the capacitor myself, but I also knew HVAC components can be dangerous if handled incorrectly. If I was unsure about discharging the capacitor or wiring it properly, I would rather call a technician. In my experience, professional help is worth it when safety is a concern.

9. Final Thoughts Before Buying

My biggest lesson was to never buy a capacitor just because it looks similar to the old one. I always confirm the specs, compatibility, and quality first. When I take my time and choose carefully, I get better performance and fewer problems with my Lennox air conditioner.

Final Thoughts

In my experience, the capacitor is a small but essential part of a Lennox air conditioner because it helps the system start and run properly. My takeaway is that when this component begins to fail, it can lead to weak cooling, hard starts, or a complete breakdown. I always recommend paying attention to early warning signs and replacing a faulty capacitor promptly to help keep the unit running efficiently and avoid bigger repairs.

Author Profile

Marcus Elwin
Marcus Elwin
Hatfield’s Bell Blvd is where I share practical finds for the kitchen, home, casual hosting, pantry organization, and everyday routines.

Some products are the kind you notice right away because they save time. Others are quieter. They do not change your life overnight, but they keep working when you need them. Those are often the best purchases.

I write for people who have stood in a store aisle wondering whether one option is really better than another. For people who are tired of replacing things too quickly. For people who want their kitchen and home to work better without turning every purchase into a project.

You will not find exaggerated promises here. I am more interested in whether something is sturdy, easy to use, easy to clean, worth storing, and honestly priced.