How to Disable Moisture Detected on Samsung S21 (UK Step-by-Step)

How to Disable Moisture Detected on Samsung S21 (UK Step-by-Step 2025)

If your Samsung Galaxy S21 shows the “Moisture detected in charging port” warning in the UK, it can be extremely frustrating, especially in rainy cities like London, Manchester, or Glasgow. Even if the phone feels completely dry, the sensor can remain triggered for hours. I’ve personally tested these methods on multiple S21 devices in various UK conditions, and this guide provides safe, step-by-step fixes.

For more Samsung-specific guidance, visit the Samsung Hub. Charging port and connectivity solutions can also be found in the Connectivity Hub.

Why the S21 Displays the Moisture Warning

The S21 has a sensitive moisture sensor in the USB-C port to prevent short circuits. UK-specific triggers include:

• Cold-to-warm transitions – entering a heated room after a chilly morning walk in Edinburgh or Newcastle.
• High indoor humidity – steam from kitchens or bathrooms.
• Lint or debris inside the USB-C port.
• Minor water exposure – rain splashes or moisture from pockets.
• Corrosion from long-term exposure in humid areas, especially coastal cities like Brighton and Cardiff.

From my experience, the S21 sensor can remain activated for several hours even when there is no visible moisture.

Step-by-Step Methods to Disable the Moisture Detected Warning

1. Disconnect the Charger and Power Off

Unplug the charger and switch off the phone for 5–10 minutes. This resets the sensor in most cases.

2. Dry the USB-C Port Gently

• Place the phone upright on a desk or table.
• Use a desk fan or low-heat hairdryer from 20–25cm distance for 10–15 minutes.
• Avoid inserting cotton buds or metal objects, as they can worsen the problem.

3. Clean the USB-C Port

Debris and lint often trigger false alerts:

• Use a wooden or plastic toothpick to carefully remove trapped fibres.
• Use compressed air for short bursts if available.

4. Clear USB Settings Cache

Go to:

Settings → Apps → Show system apps → USBSettings → Storage → Clear data

5. Disable USB Default Configuration via Developer Options

This method often helps when the warning persists:

1. Enable Developer Options: Settings → About phone → Software information → Tap “Build number” 7 times
2. Navigate to Settings → Developer Options → USB default configuration and disable it temporarily.

6. Use Wireless Charging (Optional Workaround)

The S21 supports wireless charging, which bypasses the USB-C port entirely while the alert is active.

7. Restart in Safe Mode

Some third-party apps may interfere with the sensor:

1. Hold the power button
2. Long-press Power off
3. Select Safe Mode

If the alert disappears in Safe Mode, a third-party app is likely causing the issue.

When Hardware Is the Problem

Signs that the moisture warning is due to hardware include:

• The warning persists even after drying and cleaning
• Charging only works at certain cable angles
• Loose USB-C port or intermittent connection

In high-humidity regions like Cardiff or Liverpool, corrosion is a common cause. Repair is usually required at a local shop or Samsung Authorised Service Centre.

UK Repair Costs (2025)

Local Repair Shops (London, Birmingham, Manchester)

• USB-C sub-board replacement: £50–£85
• Cleaning & diagnostics: £10–£25

Samsung Authorised Centres

• Replacement: £95–£130 depending on location
• Waterproofing seals restored during service

Samsung Care+ can reduce costs to £25 excess.

UK Prevention Tips

• Keep the phone upright after rain exposure or entering from cold outdoors
• Use a USB-C dust plug in wet or coastal cities like Brighton or Aberdeen
• Regularly clean the port to prevent lint and debris accumulation
• Avoid charging immediately after temperature changes from cold to warm

For more maintenance guidance, see AvNexo’s Screen Tools Hub.

Final Thoughts

Disabling the moisture detected warning on the Samsung Galaxy S21 in the UK is mostly a matter of proper port cleaning, drying, USB cache resets, and Developer Options adjustments. Most false alerts are software or debris-related. If the warning persists, professional repair via a local shop or Samsung service centre replacing the USB-C sub-board is the most reliable solution.