the company that fitted it will have changed the eng code,you will have to reset it back to the factory default codes,but then you will have to reprog the panel,to refresh the nvm,first remove the mains power from panel,open the end station,remove red lead from the battery,remove the nvm,(its the small chip at the top left of pc board,to left of the micro proccessor,
reconnect the battery,apply mains power,refit the nvm chip,take care with the polarity,it has a locator dot on the right bottom corner of chip,take care when inserting as the pins are very fragile,the end station will now reload factory defaults,i.e.user code 1234,engineer code 7890,now you will need to reprogramme the system.hope this helps
mm
September 2010