How to Stop TP‑Link Kasa Smart Plug HS300 from Resetting After Power Loss

The TP‑Link Kasa Smart Plug HS300 is a popular addition to many smart homes. Its ability to turn devices on and off, schedule tasks, and provide energy usage reports makes it a valuable tool. Yet one frustration that many owners face is that the plug “resets” after a power loss. The schedule disappears, Wi‑Fi credentials are lost, and the device has to be re‑configured from scratch.
Below is an in‑depth guide that explains why this happens and offers a complete set of solutions to keep your HS300 configured even after a blackout or a routine power interruption.

Why Does the HS300 Reset After Power Loss?

The HS300 is built to be a low‑cost, battery‑free appliance. It relies on the host power supply to keep its non‑volatile memory powered during normal operation. When power is cut, the plug’s internal storage (NVRAM) is refreshed. The device firmware is designed to clear user settings to avoid stale configurations that could cause unpredictable behavior.
In effect, a power loss is treated as a “hard reset” rather than a “soft reboot.” This design choice keeps the device safe from corrupted data but inconveniences users who prefer seamless operation.

What Kind of Power Losses Trigger a Reset?

• Utility outages – a full loss of mains power for a few seconds or minutes.
• Power‑surge protection devices (e.g., whole‑house surge protectors) that momentarily cut the plug’s supply.
• Unplugging the plug – even if the plug is switched off before disconnecting, the internal circuit sees the loss of mains power.
• Smart outlets or power strips that supply only a portion of the mains voltage, occasionally dropping the supply.

Any of these scenarios will trigger the HS300 to wipe its settings. Understanding the cause helps decide the most effective mitigation strategy.

The Impact of a Reset

• All scheduled on/off times vanish.
• Wi‑Fi credentials are erased, forcing a reconnection.
• Energy usage history is cleared.
• Any linked services (e.g., Alexa, Google Home) need to be re‑authorized.
• The plug appears as a new device in the Kasa app, requiring full setup.

This is especially disruptive when the HS300 is used to run critical appliances such as a refrigerator, a smart heater, or a security system.

Strategies to Stop the Reset

Below are three main approaches to prevent or at least minimize the impact of resets:

1. Prevent Power Loss – Use a UPS or ensure a stable power source.
2. Configure the Plug to Retain Settings – Adjust firmware and app options to preserve user data across power cycles.
3. Automate Re‑Configuration – Set up a quick re‑install routine that restores the plug instantly after a reset.

The following sections walk through each strategy in detail.

1. Protecting the Plug from Power Loss

1.1 Use an Uninterruptible Power Supply (UPS)

A UPS keeps a device running on battery for a short period during a power outage. For a single HS300, a small UPS with at least 5 W of capacity will maintain power for several minutes, giving the plug enough time to shut down gracefully or to survive the outage entirely.

Steps to Set Up a UPS for HS300

• Connect the UPS to a mains outlet.
• Plug the HS300 into the UPS.
• Ensure the UPS battery is fully charged before use.
• If your home already has a UPS, verify that the HS300 is connected directly to the UPS’s protected outlet, not an unprotected one.

1.2 Use a Dedicated Power Strip

If a UPS is not an option, a quality power strip with surge protection and a built‑in power indicator can provide a more stable supply. Look for strips that have:

• A built‑in voltage regulator.
• A reset button that does not cut power to the plug.
• An indicator that the strip is functioning correctly.

By using a dedicated strip, you isolate the HS300 from irregular voltage fluctuations caused by other appliances.

2. Configuring the HS300 to Preserve Settings

While the device defaults to wiping settings, certain firmware and app settings allow it to retain data across power cycles. The process involves updating firmware, enabling local mode, and turning on “Save Wi‑Fi on Power Loss” if available.

2.1 Update the HS300 Firmware

Outdated firmware often lacks the latest stability improvements. Follow these steps:

1. Open the Kasa Smart app on your phone.
2. Locate the HS300 device icon in the device list.
3. Tap the gear icon to open Settings.
4. Scroll to the bottom and tap Firmware Update.
5. If an update is available, download and install it. The plug will reboot automatically once the process completes.

Why Updating Matters
Recent firmware releases include fixes for the power‑loss reset issue and improvements to the local network stack that help the plug remember its configuration.

2.2 Enable Local Mode

Local mode allows the HS300 to respond directly to your home network without relying on Kasa’s cloud servers. This reduces the dependency on external services and ensures quicker recovery after a reset.

Steps to Enable Local Mode

1. In the Kasa app, go to the HS300 Settings page.
2. Find the Control tab and tap Local Mode.
3. Toggle the switch to ON.
4. Confirm the action. The plug will restart.

Benefits of Local Mode

• Faster command response times.
• Reduced need to re‑authenticate after a reset.
• Ability to use third‑party local integration tools (e.g., Home Assistant) that can automatically restore schedules.

2.3 Turn on “Save Wi‑Fi on Power Loss”

Some firmware versions offer an option called “Save Wi‑Fi on Power Loss.” This tells the device to keep its Wi‑Fi credentials even when power is lost.

Enabling the Option

1. Within the HS300 Settings, locate Advanced Settings.
2. Find the toggle labeled Save Wi‑Fi on Power Loss.
3. Turn it ON and confirm.

If you do not see this option, your firmware may be too old, or it may not be supported on HS300. In that case, use the UPS strategy or local mode as a fallback.

3. Automating Re‑Configuration

Even with the above safeguards, a reset can still occur. Automating the re‑setup process can reduce downtime dramatically.

3.1 Use a Third‑Party Home Automation Platform

Platforms like Home Assistant or openHAB can monitor the status of your HS300. When a reset is detected, the platform can issue commands to restore the plug’s schedule and settings automatically.

Setting Up Home Assistant to Restore the HS300

1. Install Home Assistant on a Raspberry Pi or other compatible device.
2. Add the Kasa integration: Configuration → Integrations → Kasa Smart.
3. Allow Home Assistant to discover the HS300.
4. Create an automation that triggers when the plug’s “available” state changes to “off” and then to “on.”
   • Trigger: state_change: entity_id: switch.hs300, to: 'on'
   • Action: Send a “Set schedule” command using the Kasa API or Home Assistant’s REST command service.
5. Save the automation.

When the HS300 reconnects, Home Assistant pushes the restored schedule back to the device.

3.2 Scripted Re‑Login via Kasa CLI

For tech‑savvy users, Kasa provides a command‑line interface that can be scripted to log in and set schedules after a reset.

Example Bash Script

#!/bin/bash
# Kasa Re‑Setup Script

# Kasa credentials
USERNAME="your_email@example.com"
PASSWORD="your_password"

# Device ID
DEVICE_ID="1234567890"

# Schedule: Turn on at 08:00, off at 22:00
START_HOUR=8
END_HOUR=22

# Log in to Kasa
LOGIN_RESPONSE=$(curl -s -X POST https://api.kasa-smart.com/auth/login \
  -H 'Content-Type: application/json' \
  -d '{"account":"'"$USERNAME"'", "password":"'"$PASSWORD"'", "countryCode":"US"}')

# Extract session token
TOKEN=$(echo $LOGIN_RESPONSE | jq -r '.session.token')

# Set schedule
curl -s -X POST https://api.kasa-smart.com/device/control \
  -H 'Content-Type: application/json' \
  -H "Authorization: Bearer $TOKEN" \
  -d '{
        "deviceid": "'"$DEVICE_ID"'",
        "cmd": "setSchedule",
        "data": {
          "scheduleType": 1,
          "enabled": true,
          "startTime": "'"$(printf "%02d" $START_HOUR)"':00",
          "endTime": "'"$(printf "%02d" $END_HOUR)"':00"
        }
      }'

Run this script automatically using a cron job that checks the plug’s status every minute. If the plug is offline, the script waits until it comes online and then restores the schedule.

4. Practical Troubleshooting Checklist

Follow the table sequentially. Most resets can be avoided by ensuring the plug has a stable power supply and up‑to‑date firmware.

5. When to Contact TP‑Link Support

If after applying all the above measures the HS300 still resets unpredictably, it may be a hardware defect. Gather the following information before reaching out:

• Model and firmware version (e.g., HS300 v4.2.3).
• Serial number (found on the plug label).
• Environmental details (typical mains voltage, presence of surge protectors).
• Exact symptoms (how long the reset occurs, what settings are lost).

Send a concise email or use the support portal. TP‑Link often recommends a factory reset and a re‑pair attempt before replacing the unit. In many cases, they will offer a warranty replacement if a hardware fault is confirmed.

6. Summary

• The HS300’s reset behavior is a safety feature that wipes user data during a power loss.
• Preventing the reset involves securing the power source (UPS, dedicated strip) and updating firmware.
• Enabling local mode and the “Save Wi‑Fi on Power Loss” option helps the plug retain settings.
• Automation tools such as Home Assistant can restore schedules automatically after a reset.
• A detailed troubleshooting checklist ensures you address all potential causes.
• If the problem persists, contact TP‑Link support with detailed information for a possible replacement.

By combining a reliable power supply, the latest firmware, local network configuration, and automation, you can effectively stop the TP‑Link Kasa Smart Plug HS300 from resetting after power loss. This keeps your smart home running smoothly and eliminates the need to re‑configure your devices every time the lights flicker.