Mini split Wi-Fi failures are almost always network compatibility, not hardware - and the single biggest culprit is 5GHz. Most units' radios speak 2.4GHz only, and modern mesh routers that auto-steer devices to 5GHz break pairing invisibly.
Safe checks first
- Force 2.4GHz for pairing. If your router broadcasts one combined network name, temporarily split the bands or create a 2.4GHz-only guest network and pair against that. This resolves the majority of "app can't find unit" reports.
- Enter AP mode properly. Units pair via a temporary access point (AP on the display on many models). Follow the app's sequence exactly - the AP window times out in minutes; restart the sequence rather than retrying a stale screen.
- Phone-side gotchas. Grant the app local-network and location permissions (required for Wi-Fi scanning on both phone platforms); turn phone off cellular during pairing so it doesn't route around the unit's AP.
- Signal reality. The unit's antenna is behind plastic near a wall penetration - marginal at range. If the phone shows one bar at the unit, the unit has less; a mesh node or extender near the room fixes the chronic-dropout version of this.
- Router settings that block IoT. WPA3-only mode, "AP/client isolation", and band steering all break these radios - WPA2/WPA3 mixed, isolation off for the IoT network.
- Power cycle both - unit at the breaker, router too; re-pair fresh (delete the stale device entry in the app first).
Beyond the safe checks (technician scope)
A unit that never broadcasts its AP mode despite the correct button sequence may have a failed Wi-Fi module (often a small replaceable dongle/board). FH CC-class module/sensor codes - check the library. Remember the unit heats and cools fine without Wi-Fi; the remote still works while you sort it.
When to stop and call
Never a safety issue by itself - call when the AP never appears after the manual's exact sequence, or if the app worked for months and died with an error code on the display.
Sources
No model-specific systems are linked from this guide yet.