UniMac Industrial Washer Slow Drain Detected: Message at Cycle End
Slow Drain Detected means the control sensed a longer-than-average drain time during a machine cycle. The message appears on the Door Unlock menu and is logged in the last 8 errors. The cycle has already ended and the door can be opened.
Low: an early notice at the end of the cycle.
- Code
- Slow Drain Detected
- Maker
- UniMac
- Equipment
- Industrial laundry
- Applies to
- UniLinc control: UW35TV, UW60TV, UW80TV, UW100TV, UW125TV, UW150TV, UWL/UWN/UWU 035-150 T3 models
What does UniMac Slow Drain Detected mean?
The UniLinc control keeps track of how long drains normally take. If a drain in the current cycle takes noticeably longer than average, it does not stop the cycle. Instead, once the cycle has ended, it shows Slow Drain Detected on the Door Unlock menu and logs the event in the queue of the last 8 errors. The manual lists no further action. The user can simply unlock and open the door. The message is an early warning: the drain is working, but slowly, and a drain that is slowing down tends to become a stopped drain. Lint in the outlet, a partly closed valve or a building drain that is starting to back up are the usual causes. A load that holds a lot of water can also drain slower, so repeated events matter more than a single one.
Affected models and control systems
UniMac UniLinc control on the UW35TV, UW60TV, UW80TV, UW100TV, UW125TV and UW150TV washer-extractors and the UWL, UWN and UWU 035-150 T3 models.
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
- Slow Drain Detected on the Door Unlock menu
- Cycle completed normally
- Water slow to leave the tub
- Message repeats on later cycles
Possible causes
Likely causes — what usually sits behind Slow Drain Detected on this control. A technician confirms which one it is before any part is replaced.
- Drain time longer than average during a cycle
- Lint or debris partly blocking the drain outlet
- Drain valve not opening fully
- Building drain or trench slowing down
- Very large or absorbent load holding water
Safe checks before calling for service
- Unlock and open the door, as the manual allows.
- Look at the discharge area and floor drain for slow flow.
- Note how often the message appears.
- Check that the drain hose is not kinked.
- If it repeats, tell the technician and give the list of recent errors.
How a technician diagnoses Slow Drain Detected
- Read the last 8 error queue.
- Time a drain and compare it with earlier runs.
- Check the drain valve and outlet for lint.
- Check the building drain.
- Clear the restriction and confirm drain times return to normal.
- A drain that slows can lead to Drain Alarm Error.
- The drain valve runs at line voltage.
- Working on the drain may involve trapped hot water.
How Slow Drain Detected differs from similar codes
Slow Drain Detected is a notice at cycle end. Drain Alarm Error stops the cycle during the drain.
Technical reference
- Document
- Washer-Extractor Pocket Hardmount UniLinc Control Programming (PHM1401C)
- Maker documentation
- UniMac owner support
- Edition
- Part No. F8138801R3, September 2009
- Models / control
- UniLinc control: UW35TV, UW60TV, UW80TV, UW100TV, UW125TV, UW150TV, UWL/UWN/UWU 035-150 T3 models
- Section
- Diagnostic: Machine Errors (pp. 56-59) (p. 59)
- 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 UniMac industrial laundry error codes
Do I need to do anything?
The manual lists no action. The door can be opened.
Why does it matter?
It is an early warning that the drain is slowing.
Is it the same as Drain Alarm Error?
No. That one stops the cycle when the drain takes too long.
Need help with UniMac Slow Drain Detected?
A technician confirms the cause on site and gives you the price in writing before any work starts.