Air conditioning remote or app not working? Fix it in five minutes

Five-minute checks

• Fresh batteries — and check the contacts for corrosion, which is very common in kitchens and conservatories.
• Point a phone camera at the remote's LED and press a button. If you see a faint purple flash on screen, the remote transmits fine and the fault is at the unit's receiver.
• Clear line of sight: aim at the indoor unit's display window from under 5 metres.
• Check the display isn't showing a lock symbol, or that child lock isn't engaged (usually holding two buttons for 3 seconds).
• Power-cycle the indoor unit at the isolator or breaker for 60 seconds, then retry.

Running the unit without a remote

Almost every wall unit has a hidden manual button behind the fascia — lift the front cover and look near the right-hand edge. One press typically starts an automatic mode at around 24°C. That gets you cooling until a replacement remote arrives.

Universal remotes work with most LG, Daikin, Mitsubishi and Samsung units for around £12–£20, but a genuine remote is worth it if you rely on timers or specific modes.

If it's the Wi-Fi app instead

• Check the unit is on a 2.4GHz network — most AC modules cannot see 5GHz.
• Router changes, new passwords and mesh extenders all break pairing; re-run the setup from scratch.
• Reset the Wi-Fi module (usually holding a button on the remote or module for 5 seconds until it beeps).
• The physical remote will always keep working even when the app is unpaired.

When it's actually the unit

If the remote transmits (confirmed by the camera test), a new remote also fails, and the manual button does nothing, the fault is the display/receiver board or the indoor PCB. Replacement receiver boards are typically £120–£260 fitted; a full indoor PCB is £220–£400.

FAQ