Here's a view of my door and its broken torsion spring. This door is 10 feet wide and 7 feet high, constructed of 3/4 thick hollow wood panels inside with 3/4 inch plywood siding outside to match the house exterior. This is original to the house which was constructed in 1978, and is much heavier (238 pounds, as I measured later as described below) than the steel doors most common today in new construction. The 10-foot width is a little larger than usual for a one-car garage; such doors are typically only 7 or 9 feet wide. The ceiling height is 9 feet, providing 18 inches clearance above the torsion shaft. This is in a 3-car garage with 3 separate extra-wide doors. Every man's dream! ('cept when the door is broke.)
Capable of lifting a seven-foot garage door up to 500 pounds in weight, the SilentMax 750 comes with a number of convenience features for automatic and remote use. The included wireless keypad and dual remote controls will insure that you are the only one that has access to the door. Compatible with a number of in-car remote systems like HomeLink, you can also keep the remotes at home if you are worried about losing the “keys.”
The best garage door openers can be controlled from a remote location through your phone. If you’ve ever left home and had a moment of panic, not knowing if you left the garage door open, this feature can give you peace of mind. The door opener’s built-in Wi-Fi connects directly with your home Wi-Fi router, which allows you to close your garage door from wherever you are through a MyQ smartphone app. The Chamberlain Group opener has this feature – it’s a 1-horsepower garage door opener with extra lifting power for unusually heavy doors of over 500 pounds.
An intermediate stage of the garage door opener market eliminated the DIP switches and used remotes preprogrammed to one out of roughly 3.5 billion unique codes. The receiver would maintain a security list of remotes to which it would respond; the user could easily add the unique remote's code to the list by pressing a button on the garage door opener while activating the remote control. The large number of codes made the brute force try-all-possible-digital-codes attacks infeasible, but the systems were still vulnerable to code grabbers. For user convenience, these systems were also backward compatible with the older DIP switch remote codes, but adding an old technology remote to the security list made the garage door opener vulnerable to a brute force attack to find the DIP switch code. The larger code space approach was an improvement over the fixed DIP switch codes, but was still vulnerable to the replay attack.