Hi Andy - we are in the same situation. Moved into a house with a fitted Chubb alarm, the thing started making a beeping noises during the middle of a movie, and then part way through the next movie the things starts wailing like bloody murder. We called chubb, as apparently it needs to be "reset" - however, charging over $400 5 days before Christmas just seems mean, when they just have a code to put in.
Can you pretty please share the engineers code so we can turn this darn alarm off and put our newborn baby to bed?