Hi ,when the power went off at home my optima xl6 alarm came back on but the buttons would not respond,all lights are on though. I have since found out the battery needs replacing(well its 15 years old). i want to change the battery but need to know how to do this without setting off the alarm and if there is also a battery in the bell.
Regards Ken

Ken Sadler, August 2007

we have the same problem I have ordered a new battery but what is the enginneers code? my husband has disconected the bell outside.

heather, June 2012

If bat dead,kill the mains.open panel remove any bell loops,replace with spare wire loops.no bells no noise.put in new bat while depressing middle trip spring.put mains back on ,put in code then engineer code.goodluck

Mik Mac, May 2012

There is a section on Alarmhelp.net on how to change the battery.

dai, August 2007