How to Install Start Capacitor WP8572720 in a Whirlpool Vacuum
Before You Start
A start capacitor can hold an electrical charge after power is removed. Treat it with care. You should unplug the vacuum before opening any panel or touching any internal part. Do not work on the vacuum while it is connected to power.
You also need a clean work area. A table with good light works better than the floor. Lay down a towel so small screws do not roll away. Take photos before removing wires. Those photos help you return each wire to the correct place.
Part WP8572720 is the OEM number provided for this repair. Do not match by looks alone. Capacitors can look alike but serve different needs. The safest path is to match your model number and part number using your vacuum’s label and trusted support information.
The compatible models provided for this article are:
| Whirlpool model number |
|---|
| 110.20702990 |
| 110.20722990 |
| 110.23812100 |
| 110.26912691 |
| 110.28892790 |
If your model number is not listed here, do not guess. Check your model tag and compare it with official part support before ordering or installing.
What the Start Capacitor Does
The start capacitor helps the motor start. Think of it as a short power boost during startup. Once the motor gets moving, the capacitor’s job ends until the next start.
When the capacitor fails, the motor may not get that boost. Your Whirlpool vacuum may not start as expected. It may hum, stall, or act weak at startup. The listed symptom here is broad: the vacuum is not working properly. That can point to several causes, so you should inspect before replacing the part.
A bad power cord, switch, clogged airflow path, damaged wiring, or failed motor can also cause trouble. That matters because a capacitor is not a magic fix. You want to replace it when the signs and inspection make sense.
Start capacitors are electrical parts. They are small, but they deserve respect. Do not open, crush, puncture, or heat one. If the capacitor looks swollen, cracked, leaking, or burned, handle it carefully and replace it.
Safety First
Unplug the vacuum. That is the first step and the most important one. Do not rely on the switch alone. A switched-off vacuum can still expose you to live power if it stays plugged in.
Let the vacuum sit for a few minutes after unplugging it. Keep your hands away from terminals until you can access the part safely. If you know how to discharge a capacitor safely, follow proper electrical practice. If you do not, stop and get help from a qualified repair person.
Wear safety glasses. Internal plastic clips can snap loose. Dust can also fall from the housing. Gloves can help protect your hands from sharp plastic edges or metal brackets.
Do not work in a wet area. Keep drinks, water, and cleaning fluids away from the work surface. If the vacuum has been used on damp debris, let it dry fully before opening it.
If you smell burning or see melted insulation, stop. That damage can point to a larger electrical fault. Replacing the start capacitor alone may not solve the risk.
Tools and Supplies
You may not need every tool listed here. The exact fasteners can vary by design. Since no special tool list was provided, use a basic repair setup.
You may need:
- Screwdrivers that fit the housing screws
- Needle-nose pliers
- Work gloves
- Safety glasses
- A small container for screws
- Phone camera for wire photos
- Clean cloth
- Flashlight
- Replacement start capacitor WP8572720
Use the right screwdriver size. A loose fit can strip a screw head. Press firmly and turn slowly. If a screw resists, check for hidden clips or another fastener before forcing the housing apart.
Needle-nose pliers help you pull wire connectors by the terminal, not by the wire. Pulling on the wire can loosen or break the connection. That can create a new failure after the repair.
How to Install Start Capacitor WP8572720 Safely
Common Mistakes That Cause Trouble
The biggest mistake is skipping the model check. You may have the right-looking part and still have the wrong part for your vacuum. Always confirm fit by model number and OEM number support.
Another mistake is pulling wires by the wire instead of the connector. That can break the conductor inside the insulation. The wire may look fine but fail under load.
Some people also forget photos. That creates stress during reassembly. A photo takes seconds and can save the repair.
Do not force the housing apart. Hidden screws and clips are common. If the cover flexes too much, stop and inspect the seam. Broken tabs can cause rattles later.
Do not ignore heat damage. A burned terminal means the connection may have been loose, overloaded, or damaged. Replacing only the capacitor may leave the deeper problem in place.
Symptom Checks Before You Replace the Part
The stated symptom is that the vacuum is not working properly. That can mean several things. Use this quick check before you decide the start capacitor is the likely cause.
| What you notice | What it may suggest | What to check first |
|---|---|---|
| Motor hums but does not start | Weak startup circuit or motor issue | Capacitor area, wiring, motor housing |
| Vacuum acts dead | Power path issue | Outlet, cord, switch, internal wiring |
| Starts sometimes, then fails | Loose connection or weak component | Wire terminals, switch, capacitor |
| Burning smell | Electrical damage | Stop and inspect before testing again |
| Weak suction but motor runs | Airflow issue | Filters, hose, clogs, seals |
A start capacitor mainly affects startup. If the vacuum starts and runs but has poor suction, look for clogs and airflow problems first. A capacitor will not fix a blocked hose.
If the vacuum has no sound at all, check the outlet and cord before opening the vacuum. You can test the outlet with another device. Do not open the plug or cord unless you know how to repair electrical cords safely.
Original Repair Decision Matrix
Use this matrix to decide your next move. It keeps the repair focused and helps you avoid parts guessing.
| Condition | Best next step | Why it matters |
|---|---|---|
| Model number matches supplied compatibility | Continue with part verification | Fit is more likely |
| Model number does not match | Check official support before ordering | Guessing can waste time |
| Capacitor looks swollen or cracked | Replace with verified part | Physical damage is a strong warning |
| Terminals look burned | Stop and inspect wiring | Heat damage can spread |
| Motor hums at startup | Inspect capacitor and motor circuit | Startup parts may be involved |
| Vacuum runs but suction is weak | Check airflow path first | Capacitor does not create suction |
| You are unsure about discharge safety | Get qualified help | Stored charge can injure you |
This table does not replace testing. It helps you choose the safest next step with the facts you have.
Why Model Matching Matters
Whirlpool parts can vary by model. A small change in design may change the correct electrical part, mount, or wire layout. That is why model matching matters more than shape or size.
The supplied compatible models are specific. If your vacuum shows one of those exact numbers, you can move forward with more confidence. If your label shows a different number, check official Whirlpool support before buying or installing WP8572720.
Use the full model number from the label. Do not rely on a sales name, color, or photo. Those details are not enough for part matching.
If the model label is worn, use your owner paperwork if you still have it. Whirlpool’s online owner resources can also help you locate support information.
When the Capacitor Is Not the Problem
A vacuum can fail for reasons outside the start capacitor. You save time when you know the difference.
If the motor runs but suction is poor, inspect the hose, filters, dirt path, and seals. A clog can make the vacuum seem weak even when the motor works fine.
If the vacuum shuts off after running, it may be overheating. Check airflow and dust buildup. A blocked path can strain the motor.
If the vacuum has no power at all, check the outlet first. Then inspect the cord for visible damage. Do not use the vacuum if the cord is cut, crushed, or burned.
If you hear grinding or scraping, stop running the vacuum. That sound may point to motor or moving-part damage. A capacitor replacement will not fix mechanical failure.
Installation Difficulty and Time
This repair is rated medium. That means it is not the hardest job, but it needs care. You will open the vacuum housing and handle electrical connections.
Most careful DIY repairs should take 30 to 60 minutes. The time depends on your comfort level, housing access, and screw layout. First-time repairs often take longer.
Do not rush the first half of the job. Opening the housing cleanly and documenting wires matter most. Reassembly goes faster when you have good photos.
If you feel unsure at any point, pause. A rushed electrical repair can create a worse problem than the original symptom.
Handling the Old Capacitor
Treat the old capacitor as an electrical part, not regular trash on your workbench. Keep it away from children, pets, and metal tools.
Do not cut it open. Do not crush it. Do not throw it into a fire or heat source. If it shows leakage or damage, place it in a safe container until you can dispose of it based on local rules.
Check with local waste guidance for electronic parts. Rules can vary by area. If you use a repair shop, ask whether they accept old components for disposal.
Wash your hands after handling dusty internal parts. Vacuum interiors can hold fine dust and debris.
Testing After the Repair
Your first test should be short. Plug the vacuum in, turn it on, and listen. A normal startup should sound steady. Turn it off after a brief test.
Watch for warning signs:
- Buzzing that does not change
- Burning smell
- Smoke
- Repeated clicking
- Housing vibration
- No startup at all
- Sudden shutoff
If you notice any of these signs, unplug the vacuum. Open the housing only after it is safe. Recheck wire placement, connector tightness, and the capacitor mount.
If everything sounds normal, run the vacuum a little longer. Do not test it on a heavy cleaning job right away. Give the repair a short shake-down first.
Maintenance After the Repair
A new start capacitor can help with startup, but the vacuum still needs basic care. Poor airflow can strain the motor. Extra strain can shorten the life of electrical parts.
Check filters on a regular schedule. Clean or replace them based on your vacuum’s manual. Do not wash a filter unless the manual says it is washable.
Inspect the hose and intake path for clogs. Hair, string, dust, and small objects can build up over time. A clog can make the vacuum run hot.
Keep the brush area clean if your vacuum has one. Wrapped hair can create drag. That drag makes the motor work harder.
Store the vacuum in a dry area. Moisture and electrical parts do not mix well.
What to Do Next
Need help finding the right part for your Whirlpool vacuum?
Final Checklist Before You Close the Job
Use this checklist before you call the repair done.
- You confirmed the full Whirlpool model number.
- You verified OEM number WP8572720 for this repair.
- You unplugged the vacuum before opening it.
- You took photos before removing wires.
- You handled the start capacitor with care.
- You moved each connector by the terminal, not the wire.
- You secured the new capacitor in its mount.
- You checked for pinched wires.
- You reinstalled every screw.
- You ran a short test before normal use.
- You stopped testing if you smelled burning or saw damage.
If every item checks out and the vacuum starts well, you completed the repair in a solid way.