TH-AC350 Troubleshooting Guide

Common Issues and Solutions

Issue

Possible Cause

Troubleshooting Steps

Unit will not turn on

Unit is not receiving power or controls were not fully cycled

1. Confirm the unit is plugged directly into a working wall outlet.
2. Press the Power button once firmly.
 3. If no response, try a different outlet.

Fan speed changes unexpectedly when pressing Power

Normal button behavior cycles through speed settings before powering off

1. Press the Power button once and observe indicator lights.
2. Continue pressing to cycle through High, Medium, and Low settings.
 3. Continue pressing again to turn the unit off. This is normal operation.

Unit turns off after multiple button presses

Normal power cycle sequence completed

The Power button may cycle through fan speeds before shutting the unit off. Press Power again to restart the purifier.

Filter lights stay on after replacing filter

Reset process may not have been completed

1. After replacing the filter, press and hold the appropriate filter reset button for several seconds.
2. Wait for the indicator light to turn off.
 3. Repeat if needed.

Both filter lights are illuminated

Normal during certain maintenance or reset actions

Both indicators may briefly illuminate together during reset interactions. Complete the recommended reset process and verify lights return to normal.

Filter light will not turn off

Reset button may not have been held long enough

Press and hold the related reset button firmly for several seconds until the light changes or turns off.

Buttons seem unresponsive

Control input may not be registering or issue may require service

1. Press buttons firmly one at a time.
 2. Unplug unit for 1 minute, then plug back in and retry.

Helpful Tip

If your purifier appears to behave differently after pressing the Power button multiple times, this is often normal because the unit cycles through different fan speeds before shutting off.

When to Contact Customer Support

Please contact Customer Support if:

  • The unit does not power on after trying multiple verified outlets
  • No indicator lights illuminate at all
  • Buttons do not respond after unplugging and retrying
  • The purifier cannot change operating states
  • You notice persistent abnormal lighting behavior unrelated to button use

Contact Customer Support immediately if you notice:

  • Smoke
  • Fire
  • Burning smell
  • Sparks
  • Melting components
  • Electrical damage
  • Shock or injury concerns