As a business owner, chances are the last thing you want to have malfunction is your facility's front door. If the door is stuck, is too heavy to push, or otherwise not welcoming to customers, chances are those customers will walk away and may then hesitate to come back. A door that doesn't work may also be a fire code violation and you may face fines if you don't have it repaired in a timely fashion. Before you do call for automatic door repair, however, note a few things to check as you may be able to fix the door on your own, or may know what to discuss with a contractor when you do call.
A door will only open as easily as the hinges allow; if they're old and worn, they may not move very easily and their parts may be grinding together rather than rotating. Try opening the door manually and note if the hinges seem to creak or otherwise show signs of being stuck and worn. They may also be coated with rust so they don't move freely. For some doors, you can change the hinges yourself but for many heavy doors, it's best to have a contractor install a new set of hinges so the door moves freely.
Hydraulic arm and housing
Many automatic doors have a hydraulic arm that controls the door; note if there is damage to the arm or the housing. If there is not enough air pressure in the hydraulic chamber, often caused by a dent or ding that lets that pressure escape, or the arm itself is bent, this can keep the door from opening completely or shutting as it should. As with the hinges, try opening the door manually and see if the hydraulic area is in good working order or if it's old, bent, rusted, or has damage anywhere.
When automatic doors have something blocking their sensors, they can often close and stay closed, or stay open as they don't want to close on a person or other object. Sometimes something as small as a poster added to the glass of the door or any other type of object can be read by the door as an obstruction. If your door has stopped working since you added a poster, decorative element, display near the door, alarm, and so on, try removing these and noting if that allows the door to work as it should.