Are BOJACK capacitors any good for AC repairs?
Worth it, if the numbers match
Why your AC quits right when you need it most
You flip the outside AC switch back on after a breaker trip and the compressor just hums. No spin, no cold air, just a low buzz coming from the condenser box while the house gets hotter behind you. That hum is usually one dead twenty dollar part, not a dead unit, which is exactly why people start asking are bojack capacitors any good before they spend money on something bigger.
How a dual run capacitor actually starts your compressor and fan
A dual run capacitor does one specific job: it stores a jolt of electrical charge and releases it to kick both your compressor and your condenser fan motor into motion, then keeps feeding the compressor a steady phase shift so it runs smooth once it's spinning. That's why this one part carries two ratings instead of one, 45 microfarad for the compressor side marked Herm, 5 microfarad for the fan side marked F, with the third terminal C tying both back to the common line. Get those three wires on the wrong post and nothing spins, so match the labels before you match anything else. Shape doesn't matter here, only numbers do. Round or oval, as long as the microfarad rating and voltage rating match your old part, the capacitor doesn't know the difference and neither does the motor. Voltage has one rule worth remembering: a 440V rated capacitor built like this one will run fine in a 370V slot because it's simply overbuilt for the job, but a 370V capacitor won't survive being dropped into a 440V system. The metallized polypropylene film inside handles the temperature swings that kill cheaper capacitors, rated down to negative 40 and up to 158 degrees, so it sits in a box that bakes in July and freezes in January without complaint. None of that matters if you buy the wrong microfarad number, so pull the old one and read it before you order.
You're not buying a brand name here, you're buying a spec match: same microfarad, equal or higher voltage, same three terminals. Get that right and the capacitor is the capacitor, whoever stamps their name on the can.
Who this capacitor is for, and who should call a tech instead
Worth it if
- your old capacitor reads 45+5uF at 370V or 440V
- you can safely discharge and rewire a capacitor
- you want to skip a service call for a simple part swap
- you're replacing a compressor or fan motor capacitor, not diagnosing a bigger fault
Skip it if
- you don't know your old capacitor's exact ratings
- you've never worked inside a live electrical panel
- you want a part backed by a long manufacturer warranty
- your AC problem might be bigger than a dead capacitor
Not for anyone unsure what's actually wrong with their AC, or new to working inside a live electrical panel.
The BOJACK capacitor verdict: is it worth it
If your old capacitor reads 45+5uF at 370 or 440 volts, this is a quiet yes, ten minutes with a screwdriver and a safe way to discharge the old one first. If you're not sure what's actually wrong with your unit, or you've never worked inside a live electrical panel, this isn't the place to learn, call someone.
That hum stops being a mystery once the new capacitor is seated and the fan kicks over on the first try. Ten minutes after you started, cold air is moving through the vents again and the rest of your evening goes back to being about anything other than the AC. A lot of buyers land on this one for that exact reason, a quick fix and working cooling, though plenty also mention checking back on it after a year or two rather than assuming it will outlast the unit it's feeding.
Amazon shoppers rate it 4.7 out of 5 across 3,860 ratings. That is their number, not ours.
Before you go
Is Bojack a good brand of capacitor?
Yes, for spec-matched replacements. Longevity reports range from under a year to several years, so it's not guaranteed for a decade.
What brand of capacitor is best?
No single brand is best. Match the microfarad, voltage, and terminal layout to your original part - specs matter more than the brand name.
Who makes Bojack capacitors?
Bojack is a brand sold as a universal aftermarket replacement, not tied to one HVAC manufacturer.
What are the best quality capacitors?
Look for metallized polypropylene film construction, wide operating temperature range, and voltage rating equal to or above your original part.
By the numbers
earn an unconditional yes at full priceOut of 40 industrial & scientific products we have reviewed. This one is a yes with a condition attached.
Verdict datasetQuestion indexCC BY 4.0
Full spec sheet
| Capacitance | 45 microfarad |
|---|---|
| Item Shape | Round |
| Maximum Storage Temperature | 70 °C |
| Operating Voltage | 440 volts |
| Capacitance Tolerance | 6 |
| Maximum Voltage | 440 volts |
| Mounting Type | Through-Hole Mount |
| Upper Temperature Rating | 158 °F |
