The app indicates a low battery on one or more Smart Radiator Valves; valves may stop responding or lose calibration.

Safety: Battery replacement is safe; avoid touching hot radiator surfaces.

• Install new batteries: Open the Smart Radiator Valve and replace the AA batteries with fresh alkaline cells. Do not use rechargeable batteries unless explicitly supported.
• Inspect contacts: Check for corrosion on the battery contacts and clean gently with a cotton swab and isopropyl alcohol if needed.
• Free stiff radiator pin: If the valve often struggles to move, free the radiator pin as described in the calibration procedure to reduce motor load.
• Re-calibrate: After battery replacement, run a calibration from the app to ensure correct travel.

If batteries drain within weeks despite free movement and quality cells, the valve’s electronics or motor may be faulty; replace the Smart Radiator Valve.