Ultimate Fix-It-Yourself Manual: Large appliances--Trash compactors

A trash compactor compresses trash into easily disposable bundles. A boxlike ram inside the unit is held by two power nuts that ride down and back up a pair of threaded shafts called power screws. A chain-and- sprocket assembly driven by a split-phase motor turns the screws. In use, the ram moves down until it stalls against compacted trash. A directional switch (triggered when the ram started down) reverses the motor’s rotation, moving the ram back up. As the ram reaches the top of the unit, a top limit switch stops the motor. The switches may be combined in newer units.

Because the ram exerts great force, the trash compactor has several safety switches. A drawer switch prevents operation with the drawer Open. Most units have a keyed on-off switch. When it’s not in use, keep the unit locked and the key away from children.

A freestanding model is easier to access for repair than an under-the-counter unit. Typical problems are failed switches and worn sprockets, chain, roller bearings, and power nuts. The split-phase motor may need repair or replacement (see General Troubleshooting). When making repairs, lubricate parts following the manufacturer’s directions.

Adjusting drive chain tension. Periodically check the chain’s tension by pressing your thumb against it Gaining access, right). If there’s more than ½ inch of play, loosen the motor mounting bolts; move the motor to adjust the chain’s tension, and retighten the bolts.


  • Power screw — Ram
  • Drawer tilt switch
  • Motor centrifugal switch
  • Split-phase motor
  • Drive gear
  • Sprocket

Note: Details of repair and disassembly may vary, depending on appliance model. If your trash compacter differs markedly from this one, see Appliance repair basics.

Power nut (on new units look for plastic power nut at bottom of ram) —Combination top limit / directional switch (may be two switches)

Replacing a power nut:

To access power nut, take off top cover panel. Loosen nut retainer with socket wrench or nut driver. Remove power nut by unscrewing it.

Install new power nut after applying grease (type recommended by manufacturer) to threads; bolt retainer over nut.


Don’t compact hair spray, insecticides, paint, lacquer, paint thinner, aerosol cans, or other flammable items. Never compact fireworks or ammunition.

To compact glass bottles, place them on their sides and on top of other trash, away from the sides of the bin.

Never operate a damaged compactor.

Always unplug the compactor before doing any work. Don’t place your hands inside the unit before it’s unplugged. When making repairs, beware of sharp edges inside the compactor. Make sure wires don’t touch sharp edges or get caught between moving parts.

= = =

Gaining access:

To unplug an under-the• counter unit, release bracket(s) at center or side of top. Pull out and remove drawer; slide out compactor to reach plug.

To remove top and side cover panels on either unit, unbolt them with a nut driver. Before removing bottom panel, tip unit over onto blanket or padding.

To access motor, chain, and switches on counter unit, unbolt cover panels with nut driver. To access these parts on freestanding unit, remove drive gear.

Remove console panel by unscrewing bottom of console and pushing panel up or down. You may have to remove console panel to remove top cover panel.





Compactor won’t start

Compactor starts, then stops

Motor runs but ram doesn’t move

Compactor makes odd noises

Drawer won’t open

Jammed ram

Barn stops partway

Compactor starts but doesn’t compact completely

Compactor won’t stop


Power off at outlet or faulty power cord

Drawer partway open

Faulty centrifugal, directional, drawer safety, or on-off switch

Loose terminal or damaged wire

Split-phase motor overloaded

Faulty split-phase motor

Drawer open during cycle; restart light on

Split-phase motor overloaded

Faulty top limit switch.

Loose or damaged chain or faulty drive gear

Worn power nuts

Loose or damaged chain or faulty drive gear

Dry power screws

Dirty ram cover

Faulty drawer tilt, drawer safety, on-off, or top limit switch

Debris in power screw, power nut, or ram

Faulty directional switch

Faulty split-phase motor

Debris in power screw threads or nuts

Worn power nuts

Dry power screws

Faulty on-off or top limit switch

See General Troubleshooting

Close drawer completely and start unit.

To test centrifugal and directional switches, see below; for drawer safety or on-off switch, see General Troubleshooting

Reconnect loose terminal; replace damaged wire.

Let motor cool 10 mm. Check chain tension; look for worn or clogged power nuts and screws. Test centrifugal and directional switches. Adjust or replace bad parts.

See General Troubleshooting; test centrifugal switch.

Turn switch to Start. Motor should start. While holding switch, push front of drawer; release switch right away.

See Compactor won’t start.

Test switch; replace if defective.

Check chain tension; replace faulty chain or gear.

Replace both power nuts.

See Motor runs but ram doesn’t move.

Lubricate with grease recommended by manufacturer.

Remove ram cover and scrape off debris with a putty knife.

To test top limit switch, see below; for other switches, see General Troubleshooting.

Remove debris with plastic-bristle brush or putty knife.

Test switch; replace if bad.

See Compactor won’t start.

Remove foreign material.

Replace both power nuts

Lubricate with grease recommended by manufacturer

See Drawer won’t open

[Degree of difficulty: Simple Average Complex --- Volt-ohm meter required]

Replacing or adjusting the chain:

1. Unplug the unit and access the motor . Loosen the motor mounting bolts with a nut driver; slide motor toward front of unit. Pry off the C-clip at the shaft (see Tips from the pros).

2. Gently pull the L drive gear off the shaft. Remove the chain from the drive gear’s rear sprocket. Unbolt the power screws from the frame—do not remove the nuts on the power screws.

3. Without rotating them, pull the power screws just past the frame; remove the chain from the sprockets. Place a new chain around the sprockets; adjust the chain tension . Reassemble.

Testing the centrifugal switch:

1. Unplug unit; access motor. Disconnect and remove switch. Set VOM on RX1. Probe opposite terminals closest to button (labeled BR and BU here; check your model’s wiring diagram).

Press button. The meter should read zero ohms.

Release button; VOM should show infinity. If switch fails either of these tests, replace it.

Testing a combination top limit/directional switch

1. Remove console panel. Label and detach switch wires. Unbolt switch with open-end wrench. Set VOM on RX1. Attach one VOM clip to terminal Y, second clip to R (check wiring diagram for your model).

2. Press the switch lever or button. The VOM should show zero ohms. Move the second clip from R to each of the other terminals in turn. VOM should show infinity each time.

3. Release lever. Attach one clip to terminal Y, the other to GY. VOM should show zero ohms. Move the second clip from GY to each of the other terminals in turn; VOM should show infinity each time.

4. Attach one clip to BR, other $ clip to 0 or V; look for zero ohms with lever out, infinity when pressed. Move second clip to other terminals in turn; look for infinity readings with lever both up and pressed.

Prev. | Next

Top of Page  All Related Articles  Home