How to factory reset a Zyxel router
Reset button location
Recessed pinhole on the back, labelled "Reset" or "RESET".
Hold duration
10 seconds
What gets reset
Restores factory defaults: admin / 1234 (or per-device sticker), Wi-Fi name/key, and any custom NAT / firewall rules.
Brand-specific notes
Newer Zyxel firmware uses a sticker-printed unique admin password instead of 1234.