Kenmore Washing Machine F21 Error Code: Step-by-Step Fix

Quick Summary Answer: The Kenmore F21 error code indicates a long drain situation where the washing machine fails to drain water within the allocated eight-minute limit. The most common cause is a clogged drain pump filter (coin trap) or a failed drain pump motor itself. To fix it quickly, unplug the washer, drain the water manually, clean out the pump filter, and inspect the pump impeller for obstructions or electrical failure.

Your Kenmore front-load washer is full of soapy water, your clothes are soaking wet, and the digital display is flashing a stubborn “F21” error code. This is one of the most common issues US homeowners face with Kenmore washers, particularly the Elite and HE series.

We see this error weekly on service calls. It simply means your washer’s Central Control Unit (CCU) detected that the water level did not drop sufficiently within eight minutes of the drain pump turning on.

Fortunately, you do not need to spend hundreds of dollars on a professional repair technician to resolve this. Most homeowners can diagnose and fix this issue in under an hour using basic household tools.

What Causes the Kenmore F21 Error?

When your washing machine enters the drain portion of its cycle, the control board sends electrical power to the drain pump. A pressure switch monitors the water level inside the tub and sends feedback to the main control board.

If the pressure switch tells the control board that water remains in the tub after eight minutes of pumping, the machine halts the cycle to prevent flooding. It then flashes the F21 code to alert you of the failure.

There are four primary culprits behind this failure:

A physical blockage in the pump filter (often called the coin trap).
A kinked, clogged, or improperly installed external drain hose.
A mechanical or electrical failure of the drain pump motor itself.
A blocked pressure switch hose giving false readings to the control board.

WARNING: ELECTRICAL AND WATER HAZARDS Before attempting any diagnostic steps or repairs on your Kenmore washing machine, always disconnect the unit from the power source by unpluging it from the wall outlet or switching off the circuit breaker. Water and electricity are a lethal combination, and you will be working directly with the appliance’s electrical components and drainage system. Keep old towels, a shallow pan, and a wet-dry vacuum nearby to manage water spills.

Diagnostics and Repair Overview

Before you start pulling panels off your washing machine, prepare your work area. This table outlines the typical steps, estimated time investments, necessary tools, and approximate parts costs.

Diagnostic Step	Est. Time	Tools Needed	Cost
Emergency Draining	15-20 Mins	Shallow pan, towels, wet-dry vac	$0
Filter & Coin Trap Cleanout	10 Mins	Pliers, rag, flashlight	$0
Drain Hose Inspection	10 Mins	Screwdriver, flashlight	$0
Multimeter Testing of Pump	15 Mins	Multimeter, nut drivers	$10 - $20
Drain Pump Replacement	30-45 Mins	1/4” Nut driver, pliers, new pump	$35 - $80

Step-by-Step Diagnostic and Repair Checklist

Follow this systematic checklist to identify the exact cause of your F21 error. Work through these steps in order, from the simplest and cheapest fixes to the more advanced component replacements.

Phase 1: The Emergency Water Drain

Before you can inspect any internal components, you must empty the standing water from the washer tub. Opening the pump filter with a full tub will release several gallons of dirty water onto your floor.

First, locate the drain hose at the back of your washer. If possible, lower the hose into a shallow bucket placed on the floor to let gravity drain the water.

If gravity draining does not work, you must prepare for a controlled spill. Lay down several thick towels in front of the bottom access panel of the washer.

Place a very shallow baking pan directly under the pump filter cap. Slowly turn the filter cap counter-clockwise to allow a small stream of water to escape into the pan.

Tighten the cap back up when the pan fills, empty the pan, and repeat this process until no more water escapes. If you have a wet-dry utility vacuum, you can hold the vacuum hose directly against the filter opening as you unscrew it to suck up the water instantly.

Phase 2: Cleaning the Drain Pump Filter

The drain pump filter, or coin trap, is designed to catch foreign objects before they damage the pump impeller. Over time, this filter collects coins, hairpins, lint, pet hair, and even small clothing items like baby socks.

On most Kenmore front-load washers, you must remove the lower toe panel to access the filter. This panel is held in place by three hex-head screws along the very bottom edge of the machine.

Remove these screws using a 1/4-inch nut driver, then gently pull the panel down and away from the washer. Once the panel is removed, you will see the round, black plastic filter cap on the front of the pump housing.

[Washer Front Tub]
       │
       ▼
[Inlet Hose] ──► [ Drain Pump Housing ] ──► [Outbound Drain Hose]
                       │
               [ Filter Cap / Plug ]

Turn the filter cap counter-clockwise to unscrew it completely and pull it out of the housing. Do not be surprised if you find a large collection of debris wedged inside the filter basket.

Use your fingers or a pair of needle-nose pliers to remove all debris from the filter. Use a flashlight to peer inside the empty pump housing cavity.

Verify that the small plastic impeller blades at the back of the chamber are free of thread, hair, or debris. Reach in and spin the impeller blades with your finger to ensure they rotate freely.

If the impeller spins but feels loose or wobbles on its shaft, the pump assembly is damaged and must be replaced. If everything is clean and intact, wash the filter under warm water, screw it back in tightly, reinstall the toe panel, and run a test cycle.

Phase 3: Inspecting the External Drain Hose and Standpipe

If the pump filter was empty but the F21 error persists, the restriction might be further down the line. A kinked or crushed drain hose will easily trigger this error code.

Carefully slide the washing machine away from the wall so you can see the black or grey corrugated drain hose. Look for any sharp bends, pinches, or flat spots where the hose may have been crushed against the wall.

Straighten any kinks you find in the line. Next, check the connection point where the drain hose enters your home’s standpipe or laundry tub.

Make sure the hose is not pushed too far down into the standpipe. If the drain hose is inserted more than 6 to 8 inches into the pipe, it can create a siphoning effect that prevents the washer from draining properly.

Secure the hose to the standpipe using a zip tie or hook strap to maintain a proper air gap. You should also disconnect the hose from the back of the washer and blow through it to ensure there are no internal clogs.

Phase 4: Electrical and Mechanical Testing of the Drain Pump

If your filters and hoses are completely clear, the drain pump motor itself has likely failed. We can verify this using a digital multimeter to test for electrical continuity.

Access the drain pump again by removing the lower toe panel. Locate the two electrical wire terminals connected to the back of the pump motor.

Squeeze the locking tabs on the wire harness connectors and pull them straight off the metal terminals. Set your digital multimeter to the lowest setting for Ohms ($\Omega$) of resistance.

       [Multimeter]
       (Displays Ohms)
         /        \
     [Probe 1]  [Probe 2]
        |          |
    [Term 1]    [Term 2]
     [ Drain Pump Motor ]

Place one multimeter probe on each of the two metal terminals of the pump motor. A fully functional Kenmore drain pump should display a resistance reading between 10 and 20 Ohms.

If your meter displays “OL” (Open Loop) or infinite resistance, the copper coils inside the motor are burnt out. If the meter displays 0 Ohms, the motor has suffered a direct electrical short.

In either scenario, the drain pump motor is dead and must be replaced. Even if the electrical readings are normal, the pump can still fail mechanically if the internal seals leak water into the motor bearings.

Inspect the underside of the plastic pump housing for signs of water stains, rust, or calcium buildup. If you see signs of leakage, the pump must be replaced immediately.

Phase 5: Replacing the Kenmore Drain Pump Assembly

Replacing a failed drain pump is a straightforward task that you can easily complete in about 30 minutes. Make sure you have your washer’s exact model number, which is printed on a sticker inside the door frame.

Order a certified replacement pump assembly online or from a local appliance parts dealer. Once you have the new part, make sure the washer is unplugged and all water is drained.

Lay a large towel under the pump assembly to catch any residual water. Use a pair of pliers to squeeze the metal hose clamps on the large inlet hose and the smaller outlet hose.

1. Squeeze hose clamps and slide them back.
2. Pull hoses off the pump nozzles.
3. Unplug wire harness.
4. Remove mounting screws holding pump to washer base.

Slide the clamps a few inches back onto the hoses, then pull the hoses off the pump nozzles. Remove the mounting screws that secure the pump housing to the metal base of the washing machine.

Lift the old pump assembly out of the washer and set it aside. Position the new pump assembly onto the mounting brackets on the washer floor.

Secure the new pump in place using the mounting screws you removed earlier. Reattach the inlet and outlet hoses to their respective plastic nozzles on the new pump.

Slide the hose clamps back into place near the ends of the hoses to prevent leaks. Plug the electrical wire harness back onto the pump motor terminals, ensuring the connector clicks into place.

Double-check all connections to ensure everything is tight and aligned. Plug the washer back into the wall outlet and turn on the water supply.

Alternative Culprits Behind the F21 Code

If you have cleaned the filter, checked the hoses, and verified the pump is working, yet the F21 code still appears, you are dealing with a more complex issue. Two other components can mimic a drain failure.

1. The Pressure Switch and Air Tube

The pressure switch monitors the air pressure inside a small tube connected to the washer tub. As water fills the tub, air is compressed inside this tube, pushing against a diaphragm inside the switch.

If this tiny air tube becomes clogged with soap scum, lint, or grease, the pressure switch cannot detect that the water has drained. The control board assumes the tub is still full of water and triggers the F21 code.

To inspect this, unplug the washer and remove the top panel by unscrewing the screws at the back of the lid. Locate the round, plastic pressure switch mounted on the upper side frame of the cabinet.

Disconnect the thin plastic hose from the bottom of the pressure switch. Blow firmly into the hose; you should hear a bubbling or clear air sound coming from the bottom of the tub.

If the tube is blocked, clear it with hot water or replace it. If the tube is clear, the pressure switch itself may have internal electrical failure and require replacement.

2. Central Control Unit (CCU) Relay Failure

The Central Control Unit (CCU) is the computer brain of your washing machine. It contains small relays that act as electronic switches to send 120-volt AC power to the drain pump.

Over time, these relays can wear out or suffer damage from electrical surges. If the relay fails, the CCU cannot send power to the pump, even if the pump itself is brand new.

To test this, you must run the washer and use a multimeter to check for voltage at the pump harness during the drain cycle. Set your multimeter to AC Volts.

Carefully insert your multimeter probes into the two slots of the pump wire harness connector. Plug the washer in and initiate a drain cycle.

If the meter displays 120 Volts but the pump does not run, the pump is defective. If the meter displays 0 Volts during the drain cycle, the CCU is not sending power, pointing to a failed control board or damaged wiring harness.

Preventative Maintenance to Keep F21 Away

Once you resolve your F21 error, we suggest adopting a few simple maintenance habits to ensure the problem does not return. These practices will extend the life of your drain pump and improve overall washer performance.

Empty All Pockets: Before tossing clothes into the washer, check all pockets for coins, screws, hairpins, and keys. These small items are the leading cause of shredded pump impellers.
Use HE Detergent Correctly: Always use high-efficiency (HE) detergent in front-load washers. Standard detergents create excessive suds that can lock up the drain pump and trigger false F21 codes.
Clean the Pump Filter Regularly: Make it a habit to clean out the coin trap filter every three to six months. Mark your calendar so you do not forget this vital maintenance step.
Run Monthly Clean Cycles: Run a monthly maintenance cycle using hot water and a dedicated washing machine cleaner. This dissolves grease, lint, and fabric softener buildup inside the pressure switch tube.

Frequently Asked Questions

Can too many suds cause an F21 error code on a Kenmore washer?

Yes, using non-HE detergent or too much detergent creates a massive amount of suds. This foam creates an “air lock” inside the drain pump housing, preventing the impeller from moving water. The pump will spin but fail to lower the water level, triggering the F21 code.

My pump runs and water drains, but I still get the F21 error. Why?

This is usually caused by a blocked pressure switch hose or a failing pressure switch. Even though the water is gone, the control board still thinks the tub is full because the pressure switch is stuck in the “full” position. Check the thin plastic tube running from the switch to the tub for clogs.

How do I force my Kenmore washer to drain when it is locked up with an F21 error?

You can force a manual drain by unplugging the washer for two minutes to clear the control board’s memory. Plug it back in, select the “Drain & Spin” or “Rinse & Spin” cycle, and press start. If the pump is still functional, this will often bypass the initial error and empty the tub.

Is it worth replacing the drain pump on an older Kenmore washer?

Absolutely. A replacement drain pump is relatively inexpensive, ranging from $35 to $80, and the repair is simple enough to do yourself. Replacing the pump can easily add several years of life to an otherwise solid, high-performing washing machine.

Where is the model number located on my Kenmore front-load washer?

The model number is typically printed on a silver or white sticker located on the inside of the door frame or just inside the door recess. If it is not there, check the sides or back panel of the washer cabinet. You will need this exact number to order the correct replacement pump.