We may have found other answers which could help you.
Click here for Instructions House AlarmGardtec 300/500 series- key pad shows 1u. ?
Stuck button on gardtec 500?
change battery on gardtec800?
Could anyone help me with gardtec 360/580 anti-code reset?
how can I disable a Gardtec series 300 alarm?
Gardtec 800 with a battery/fuse failure?