Thermostat display shows E01 and cannot connect to the Wiser Heat Hub or app

Safety first: You normally do not need to open any mains-powered equipment for this fault. If you must access the Heat Hub wiring, isolate power at the consumer unit and verify with a suitable tester.

• Check Heat Hub power: Confirm the Wiser Heat Hub (or Wiser HubR) LEDs are on. If dark, check its fused spur or plug, and reset the circuit breaker if tripped.
• Verify network status: Ensure your router is powered and the Heat Hub’s Ethernet/Wi‑Fi indicator shows a stable connection (refer to the Wiser manual for LED meanings).
• Reduce distance and obstacles: If the thermostat is far from the Heat Hub, temporarily move it closer (if it’s a battery room thermostat) and see if E01 clears after a few minutes.
• Reboot devices: Power-cycle the Heat Hub (turn off for 30 seconds, then on). Remove the thermostat from its wall plate or batteries for 30 seconds, then refit. Wait 5–10 minutes.
• Re-pair the thermostat: In the Wiser app, go to device settings > add or re-pair room thermostat. Follow on-screen steps to put the thermostat into pairing mode and confirm the link.
• Check for interference: Keep the Heat Hub and thermostat away from large metal objects, thick masonry, and other 2.4 GHz devices (baby monitors, cordless phones, Wi‑Fi repeaters). Try changing your router’s Wi‑Fi channel if interference is suspected.
• If E01 persists: The radio module in the thermostat or Heat Hub may be faulty. Contact a qualified technician or Wiser support for module or hub replacement.