Springs are the heart of a manual rolling door. When they snap, the door becomes heavy and hard to lift. Here's what to do, from a Shenzhen repair technician.
Step 1: Identify the Problem
If your door was working fine yesterday and today you can barely lift it, the spring has probably broken. You might hear a loud bang when it happens. Don't force the door. You could damage the slats or the track.
Step 2: Assess Whether You Can Fix It Yourself
If you have mechanical experience and tools, maybe. But torsion springs are under high tension. If you're not confident, call a professional. An improperly installed spring can snap and hurt someone.
Step 3: Replace the Spring
Release any remaining tension carefully. Loosen the set screws on the winding cone. Use winding bars that fit properly — not screwdrivers or rebar. Keep your body out of the path of the bars. Remove the old spring. Measure its length, wire diameter, and inside diameter. These determine the spring's lifting force. Get an exact replacement. Don't guess.
Step 4: Install the New Spring
Slide it onto the shaft. The stationary cone goes toward the center bracket, the winding cone goes toward the end. Secure the stationary cone to the shaft. Then wind the spring. Count the turns. For a standard 2.1-meter high door, you typically need about 7 to 8 full turns. But this varies by door weight and spring spec. Over-winding is dangerous.
When to Call a Professional
If you're not comfortable with any of the steps above, stop and call a technician. Spring replacement done wrong can cause injury or door damage. For Shenzhen service, contact Heruihua at 18926001238.