Meaning
F21 on a Whirlpool washer means the machine took longer than expected to drain the tub, a condition the control board flags as a “long drain” fault. The most likely cause is a clogged drain pump filter (the coin trap), so start by draining any standing water and cleaning that filter before anything else.
⚠ Safety first. Unplug the washer or switch off its breaker before you open any panel or the coin trap. Expect standing water in the drum and pump area, so keep towels and a shallow pan ready and keep all water well away from the electrical outlet.
What the Whirlpool F21 code means
During the drain step the central control unit (CCU) watches the water level through the pressure switch and expects the tub to empty within a set window — appliance technicians put this at about eight minutes. If the water does not drop below the empty threshold in that window, the CCU stops the cycle and shows F21. On some older front-load models the identical long-drain fault appears as F02; Whirlpool documents F21 and F02 together as the same “drain times are longer than expected” fault. Do not confuse it with F20 (also shown as FH), which Whirlpool describes separately as a water-supply problem — the washer is not filling, not draining. F21 is almost always a drainage restriction rather than a failed electronic part.
Most likely causes (ranked)
| Likelihood | Cause | What is happening |
|---|---|---|
| Most common | Clogged drain pump filter (coin trap) | Lint, coins, hair, and small items pack the trap and block the pump impeller so water cannot leave the tub. |
| Common | Excess suds | Non-HE detergent or too much detergent creates thick suds that the pump cannot move, slowing the drain. |
| Common | Kinked or clogged drain hose or standpipe | A pinched hose, an internal clog, or a backed-up house drain restricts outflow. |
| Less common | Failed drain pump | A seized impeller or open motor winding means the pump runs weakly or not at all. |
| Least common | Faulty pressure switch or CCU | A stuck sensor, blocked air tube, or bad control relay wrongly reports water still in the tub. |
How to fix it, in order
- Reset the washer — press Pause/Cancel once (some models need two presses), or unplug the machine for five minutes, then restart a rinse and drain to see if the code clears.
- Drain the standing water — with power off, lower the drain hose into a pan, or open the manual drain tube near the coin trap, and let the tub empty.
- Clean the coin trap and pump filter — open the lower front access panel, unscrew the filter over a towel, and remove all lint, coins, and debris, then rinse it clear.
- Inspect the drain hose and standpipe — straighten any kinks, clear internal clogs, and confirm the house standpipe or utility sink is draining freely.
- Check your detergent — use only HE detergent in the recommended amount, because excess suds are a frequent hidden cause of repeat F21 codes.
- Test the drain pump — look and listen for the pump running during drain, check the tub-to-pump hose for a clog, and verify the impeller turns freely.
- Check the pressure switch and air tube — inspect the clear air tube for kinks or water, and confirm the switch is not stuck reading “full”.
- Suspect the CCU last — only after every drainage path is clear should the control board be considered, ideally with professional diagnosis.
Parts that may be involved
- Drain pump filter / coin trap — the first and cheapest thing to clean; blockage here causes most F21 codes.
- Drain pump — moves water out of the tub; a seized or burned-out pump will not drain.
- Drain hose — carries water to the standpipe; kinks and clogs restrict flow.
- Pressure switch and air tube — tells the control how much water is in the tub; a stuck reading can trigger the fault.
- Central control unit (CCU) — commands the pump and reads the sensor; the rare electronic culprit.
Difficulty and time
Beginner to intermediate. Cleaning the coin trap takes about 15 to 30 minutes and clears the code in most cases. Replacing a drain pump is an intermediate job of roughly one to two hours. Tools you will want: towels, a shallow pan or bucket, a screwdriver, and pliers.
When to call a pro
- The filter, hose, and standpipe are all clear but the F21 code keeps returning.
- The drain pump does not run at all and you are not comfortable testing it with a multimeter.
- You suspect the pressure switch or the CCU and need electrical diagnosis.
- Water is leaking from the pump area or wiring shows heat or burn damage.
FAQ
Can I just reset my Whirlpool washer to clear F21?
A reset may clear the display, but if a clog or restriction is present the code will come back on the next drain. Treat a reset as a test, not a fix, and still clean the coin trap.
Is F21 the same as F20 or F02?
F21 and the older F02 are the same long-drain fault. F20 (or FH) is different: it means the washer is not filling with enough water, which is a supply problem rather than a drain problem.
Why does F21 come back after I clean the filter?
Repeat codes usually point to excess suds from too much or non-HE detergent, a partial hose or standpipe clog you missed, or a weakening drain pump. Reduce detergent and recheck the full drain path.
Sources & verification
- Whirlpool Product Help — “What is an F21 or F02 Error Code on a Front Load Washer”. Manufacturer source for F21/F02 being the same “drain times are longer than expected” fault, the non-HE / excess-detergent suds cause, and the reset procedure. Accessed 20 July 2026.
- Whirlpool Product Help — “What is an F20 or FH Error Code on a Front Load Washer”. Manufacturer confirmation that F20/FH is a separate water-supply (fill) fault, not a drain fault. Accessed 20 July 2026.
- Axis Repair — “Whirlpool Washer F21 Error Code: Causes & Fix”. Repair-technician source for the ~8-minute drain window watched via the pressure switch/CCU and the clogged coin-trap filter as the most common cause (details Whirlpool’s public page does not publish). Accessed 20 July 2026.
See all washer error codes, the full Whirlpool error codes guide, or the related Whirlpool F5 E3 door-lock code and LG OE drain code.