It would be OK except every time there is a mains power glitch, the stat loses connection and I have to carry it near the boiler and press buttons to re establish. Connection then strong until next mains glitch. Most other devices automatically re connect, eg my Panasonic aircon unit (and its app)..so if I go on holiday, the first glitch and I can no longer use phone to communicate with and operate boiler due to lost pairing I cannot remotely restore....