Window-cleaning robot leaves streaks: pad, solution and timing
If your window-cleaning robot leaves streaks, establish when they appear: during a pass, on later panes or only after removing the device. Record these separately. Adding solution and another pass without inspecting the pad can make the problem harder to identify.
Three observations before another cycle
| Observation | Check | Record |
|---|---|---|
| Marks from the first pass | Pad cleanliness, attachment and preparation according to the manual | Did they appear immediately? |
| First pane looks better than later ones | How dirty the cloth has become | After which pane does the finish change? |
| One mark at the removal position | Appearance immediately before and after removal | Is the rest of the pane acceptable? |
ECOVACS support for WINBOT mini 2 identifies an overly wet pad and cloth contamination after infrequent window cleaning as possible causes. Its pad-care guidance recommends washing or replacing a dirty cloth and drying it before storage. Preparation differs by model: do not apply one WINBOT’s firmware number or instructions to every window cleaner.
A one-pane protocol
- Choose an accessible pane compatible with the device. Secure the equipment as required for normal use.
- Photograph it at an angle that makes marks visible. Note which side is dirty.
- Fit a clean, correctly prepared pad and use an approved solution. Do not increase its concentration on your own.
- Run one cycle and inspect the finish before changing another setting. Record the number of passes.
- For another trial, change one parameter and name it in your notes. Do not attribute improvement to the robot alone if you changed the cloth, solution and mode together.
Why a second pass is not a controlled comparison
The second cycle starts on partially cleaned glass. A better finish does not automatically demonstrate a superior mode. Likewise, a fresh cloth can change the result independently of spray settings. A home trial helps you find a usable routine; comparing models requires separate areas with comparable soiling.
Distinguish remaining dirt from a wet trace
Inspect the pane again after it dries. Record whether the mark disappears, remains as residue or follows the dirty part of the cloth. Do not start by scraping a glass coating or using aggressive chemicals. Establish that the defect is on the surface you cleaned, rather than between panes or on the other side.
When to stop and contact support
Stop using the device if it reports insufficient pressure, slips, has a damaged securing component or displays another stop condition in its manual. Streaks do not justify bypassing sensors. Include the model, mode, a picture of the used pad, the cleaning solution and two photographs of the same pane in a support request. That gives more useful evidence than “it cleans badly”.
A useful outcome: one repeatable procedure for the remaining panes. Add correction time and hands-on minutes to your comparison of the complete window-cleaning session.
Continue with the next step
Sources and scope
Documentation checked on 11 September 2026. Worked examples and worksheets are RoboMorrow editorial work, not results from hands-on device tests we performed.