I get it, you purchased a house with a burglar alarm and thats what you expected to get. Instead you got a house with a faulty burglar alarm, I feel your pain I just purchased a house with solar water and electric and a few weeks in the solar water stopped working. Thats the way the cookie crumbles I supposed, you pays your money and you takes your chances.
Im fairly handy and no engineering codes are required to fix it. I will be paying someone else to fix it though, I understand my limitations and I know that I can earn more money doing what I do, than I can save trying to fix it myself. Plus not fixing it properly will work out far more expensive.
So when did you buy the house?