App shows that one or more Netatmo Smart Radiator Valves are unreachable or not responding to the thermostat.

Safety: Replacing batteries and repositioning valves is safe. If you remove a valve from a hot radiator, use gloves.

• Replace valve batteries: Open the Smart Radiator Valve, replace the AA batteries with fresh alkaline cells, and re‑fit the cover.
• Improve RF path: Avoid enclosing the valve in metal radiator covers. If possible, reposition the Relay to a more central location in the home.
• Re‑pair valve: In the Netatmo Energy app, go to Settings > Manage my home > Radiator valves and follow the steps to re‑associate the valve with the Relay.
• Check for interference: Temporarily turn off nearby RF devices (wireless alarms, other smart hubs) to see if communication improves.

If the valve remains unreachable even when close to the Relay with new batteries, its RF module is likely defective and the valve should be replaced.