puroair 240 wifi light is off and i can't control it from the app anymore. how do i reconnect it?

Diagnosis

The loss of connectivity and the extinguishing of the Wi-Fi indicator light on the PuroAir 240 typically indicate a "de-authentication" event. This happens when the device's internal wireless module loses its handshake with the router's DHCP server. Common triggers include a power surge that reset the router's IP table, a change in the SSID (network name) or password, or the router automatically shifting the device to a 5GHz band when the PuroAir 240 hardware only supports 2.4GHz. When the Wi-Fi light is completely off, the unit has entered a dormant network state where it is no longer broadcasting its setup signal or attempting to ping the server. This is why the app reports the device as "Offline." To confirm the issue is network-related and not a hardware failure, check if the physical buttons on the control panel still operate the fan speeds; if they do, the main PCB is functional, and only the wireless chipset requires a reset.

How to Fix It

To restore the connection and re-pair the device with your smartphone, follow these precise steps:

1. Ensure your smartphone is connected to a 2.4GHz Wi-Fi network. If your router uses "Smart Connect" (combining 2.4GHz and 5GHz under one name), you may need to temporarily disable 5GHz in your router settings to complete the pairing.
2. Power on the PuroAir 240 and ensure it is plugged directly into a wall outlet rather than a surge protector to ensure full voltage to the Wi-Fi module.
3. Locate the Wi-Fi button on the control panel. Press and hold the Wi-Fi button for 3 to 5 seconds. Watch for the Wi-Fi indicator light to begin flashing rapidly. This indicates the unit is now in "AP Mode" (Access Point mode) and is broadcasting its own temporary setup signal.
4. Open the PuroAir app on your mobile device. Navigate to the "Add Device" or "+" icon in the top right corner of the home screen.
5. Select the "PuroAir 240" model from the list. When prompted, enter your current Wi-Fi password exactly as it appears (case-sensitive).
6. The app will now attempt to push the network credentials to the purifier. Keep your phone within 3 feet of the unit during this process to prevent signal interference.
7. Once the Wi-Fi light stops flashing and remains solid, the connection is established. You can now name the device and control the fan speeds and timers via the app.

If That Didn't Work

• Perform a Hard Network Reset: If the light refuses to flash, unplug the unit from the wall for 60 full seconds. While unplugged, hold the power button for 10 seconds to discharge any remaining capacitors in the Wi-Fi module. Plug it back in and immediately attempt the hold-down sequence on the Wi-Fi button.
• Check Router Security Protocols: Ensure your router is using WPA2-PSK (AES) encryption. The PuroAir 240 may struggle to connect to newer WPA3-only settings. Change the security mode to "WPA2/WPA3 Mixed" in your router's wireless security tab.
• Clear App Cache: On Android devices, go to Settings > Apps > PuroAir > Storage and select "Clear Cache." On iOS, force-close the app and restart your phone. A corrupted cache can sometimes prevent the app from "seeing" the device even when it is in pairing mode.
• Assign a Static IP: If the unit frequently drops offline, log into your router's admin panel (usually 192.168.1.1) and find the MAC address of the PuroAir 240. Assign it a "Static IP" or "DHCP Reservation" to prevent the router from assigning the IP address to another device.

Heads Up

• Avoid 5GHz Bands: Never attempt to connect this device to a 5GHz network; it will either fail to connect or cause the Wi-Fi light to blink an error code.
• Signal Strength: If the purifier is placed behind a thick wall or inside a closet, the Wi-Fi signal may drop, causing the light to turn off. Ensure there is a clear line of sight or a strong signal from the router.
• Firmware Updates: Once reconnected, check the app for any available firmware updates. These often contain patches for "ghost" disconnects and improved stability for newer router models.
• Power Cycle Routine: If you experience a power outage, the unit may not automatically reconnect. A quick press of the Wi-Fi button often "wakes up" the module without needing a full re-pairing process.