LG WSEP4723 wall oven will not connect to Wi-Fi or the manufacturer's app

The checks in more detail

LG appliances join the 2.4 gigahertz band only, so if your router merges the 2.4 and 5 gigahertz bands under one name, temporarily separate them or have the phone on the 2.4 gigahertz band during setup. Keep the phone and the oven close to the router. Open the ThinQ app, choose to add a product, select the wall oven and follow the steps; the oven will ask you to hold the Wi-Fi key on the panel until a light flashes or a message appears.

Enter the password carefully, since a typo is a very common reason for failure. Make sure your router does not block new devices through a MAC filter. If pairing worked but the oven cannot be controlled, check the oven for a Remote Start setting or the ThinQ key that must be enabled before the app can start a cycle; an oven for safety will not start from a phone unless the door is closed and the setting is on.

If the oven was connected before and now fails, check that your Wi-Fi name or password has not changed, restart the router and the oven by switching off at the breaker for a minute, and remove and re-add the oven in the app. A weak signal at the wall where the oven sits is another reason, so a mesh node or a repeater near the kitchen helps. Update the app. If nothing works, contact LG with WSEP4723F and the serial number.