Dexter Washer Error Code F8: Tub Slow to Drain
F8 means the tub did not empty within 7 minutes. The cycle continues. A technician checks the drain valve for a slow drain, the pressure switch tube for blockage, the pressure switch and the harness.
Medium: the cycle continues, but a tub that does not empty affects the rest of the wash.
What does Dexter error code F8 mean?
After each wash or rinse the controller opens the drain and waits for the water level to fall. It gives the tub 7 minutes. If the pressure switch still reports water at that point, the controller shows F8 and continues with the cycle. The manual's checks are about the drain and the way the level is sensed: the drain valve, which may be draining slowly, the pressure switch tube, which can be blocked, and the pressure switch and its harness. The source stops at the checks and does not name a failed part. A tub that stays partly full affects the next steps, because a spin with water in the tub is heavy and rinsing is less effective. The match to F2, which has the same 7-minute limit for filling, is clear: F2 is a fill problem, F8 is a drain problem. Lint in the drain or a blocked building drain are common causes.
Affected models and control systems
Dexter T-450 SWD Express stack washer-dryers, serial 481983 and up. The same F10 to F21 table appears in the WCAD-Series vended washers manual (8533-073-001, 11/11). Older Dexter washers number their drive codes differently.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- F8 on the display
- Water left in the tub after the drain step
- Spin sounds heavy or slow to start
Possible causes
Likely causes — what usually sits behind error code F8 on this control. A technician confirms which one it is before any part is replaced.
- Lint and debris in the drain valve
- Building drain backing up
- Pressure switch tube kinked so the switch reports water that is not there
Safe checks before calling for service
- Look at the tub and note whether it still holds water.
- Check the floor drain for backing up.
- Do not open the door while hot water is in the tub.
- Tell the technician whether the tub was empty or full when F8 showed.
How a technician diagnoses error code F8
- Read the code and see whether water remains in the tub.
- Check the drain valve for slow drain and blockage.
- Check the pressure switch tube for blockage.
- Test the pressure switch and harness.
- Check the building drain.
- Draining hot water can scald.
- The drain valve and switch are on the live controller.
- A building drain problem may need a plumber.
How error code F8 differs from similar codes
F8 is a drain time alarm. F2 is the matching fill time alarm, and F9 is the spin target alarm.
Technical reference
- Document
- Dexter Commercial Vended Stack Washer Dryer Troubleshooting, Fault Codes, And Schematics (Troubleshooting Washer Fault Errors (F-Codes))
- Maker documentation
- Dexter owner support
- Edition
- Part # 8533-070-001 (12/13), starting serial number 481983
- Models / control
- Dexter T-450 SWD Express stack washer-dryer, serial 481983 and up; the same F10-F21 table is in the WCAD-Series vended washers manual (8533-073-001 11/11)
- Section
- Troubleshooting Washer Fault Errors (F-Codes), p.6-10
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related Dexter washer error codes
Does F8 stop the washer?
No. The cycle continues.
Is it always a blocked drain?
No. A blocked tube can make the switch report water that is not there.
How is F8 different from F2?
F2 is a slow fill. F8 is a slow drain.
Need help with Dexter error code F8?
A technician confirms the cause on site and gives you the price in writing before any work starts.