FB error and thermostat cannot connect to Wi‑Fi or Protherm cloud services.

Safety: Network configuration changes are low risk, but do not open the thermostat housing with power on.

• Step 1 – Check Wi‑Fi credentials:
  • On the thermostat or companion app, re-enter the correct SSID and password.
  • Ensure the network is 2.4 GHz if the thermostat does not support 5 GHz.
• Step 2 – Improve signal strength:
  • Move the Wi‑Fi router closer or install a repeater.
  • Avoid placing the thermostat behind metal panels or in recessed boxes that block signal.
• Step 3 – Router settings:
  • Ensure MAC filtering is disabled or the thermostat MAC is allowed.
  • Open required outbound ports if specified by Protherm documentation.
• Step 4 – Reboot devices:
  • Restart the router and thermostat.
  • Attempt reconnection via the app.
• Step 5 – Hardware fault:
  • If FB persists and other devices connect fine, the thermostat’s Wi‑Fi module may be defective.
  • Replacement of the thermostat main unit is usually required.