Can you operate a garage door with one broken spring?

You can operate a garage door with one broken spring if your door has two torsion springs and one breaks, but it is not recommended to operate, as remaining spring cannot fully counterbalance door and causes strain, imbalance, and safety risk. With two torsion springs sharing load, when one breaks, door weight is only half counterbalanced, making door feel very heavy, about half of 150 to 300 pounds, so opener will strain, hum, and may only lift door few inches before stopping due to force overload, and continued use can strip drive gear, burn out motor, or cause door to go off track due to uneven lifting. Manually, you can lift door with one broken spring, but it will be heavy and require two people, and door may be crooked as one side lifts more than other, causing rollers to bind. If you must operate, disconnect opener via emergency release cord and lift manually with helpers, but do not leave door open as it can fall due to insufficient counterbalance. It is unsafe to operate door regularly with one broken spring, as second spring is also near end of life and could break, causing door to fall. Professional recommendation is to replace both springs at once costing 300 to 600 dollars, as they have same age and cycles, to restore proper balance and avoid second service call. For extension springs, if one breaks, door will be crooked and should not be operated. In emergency, you can close door with one broken spring by lowering slowly with help.