Torsion springs when wound up apply a balance of weight to the torsion pole and the pole is attached to 2 cable drums that wind up the cable attached to the bottom of door. This is the preferred spring system to have on a sectional roll up door.

When manufactures design garage doors the springs required have to be strong enough to counterbalance the weight of the door. Sometimes it is necessary to have two different size springs to achieve optimal door balance. Since torsion springs come in hundreds of different sizes and strength. If a door is not balanced correctly it will either want to open without much help. This is what they call too hot. If springs don’t have enough tension than they are too heavy to open and will slam down when closing.

The only way to get a perfect balance is to know the exact weight of the whole door. This means weighing the sections and all the hardware that it requires. This will give you exact weight and sometimes have to use two different size springs to achieve optimal balance.

There is no reason to be alarmed as a homeowner that a technician put two different sizes springs on your garage door unless there is a balance problem.