Thermostat displays F.06 and loses wireless link to the receiver

Safety: Only low‑voltage batteries are handled at the thermostat. Isolate mains before opening the receiver casing.

Checks:

• Move the thermostat closer to the receiver (within a few meters, line of sight) and see if F.06 clears.
• Check for new sources of interference: DECT phones, baby monitors, Wi‑Fi routers placed directly next to the receiver. Relocate these devices if possible.
• Replace the thermostat batteries with high‑quality alkaline cells, observing polarity. Low battery voltage can reduce RF range.
• Re‑pair the thermostat and receiver following the Glow‑worm pairing procedure (pressing the link button on the receiver and initiating pairing from the thermostat menu).

Remedy:

• If the link cannot be re‑established even at close range, the RF module in either the thermostat or receiver may be defective. Replace the faulty unit (often easier to replace both as a matched kit).
• Ensure the receiver is mounted away from large metal objects and not inside a metal cabinet, which can block RF signals.
• After replacement, test RF signal strength if the thermostat provides a diagnostic screen.