If the garage door is in the open position and starts coming down and one of the two torsion springs break in mid travel there is usually enough power in the other torsion spring for the garage door opener to either bring the garage door back up or let it down slowly.
One garage door spring or two.
Doors with one spring place more pressure on the single spring than doors with two springs.
If you have very large heavy door then two or more springs will be required.
Require only one spring.
Added pressure and stress on the center bracket or center bearing can cause premature failure.
If your garage door has two springs pulling the door up then definitely have both replaced.
Garage door in many cases will dictate how many springs are needed for your garage door if the garage.
Door is a single car door either 8 7 or 8 8 made of aluminum or other lightweight material then it will.
The garage door has one or two springs nested inside of the shaft.
The cross section of the shaft is not circular one quarter of the shaft extends outward to form an edge.
Some builders use only one spring when they install garage doors to save money but it may not be the best option for your particular door system.
Why we use oil tempered torsion springs.
One spring systems utilize a larger spring that puts added stress on the other garage door system components.
In most cases on double door 16 feet wide and larger we recommend replacing with a two spring system.
Many garage door installers avoid using two torsion springs when they install a new door in order to save money at the time.
Typically using a single spring instead of two will save just two or three dollars.
If your garage door was originally set up with only one torsion spring then you are perfectly fine with having only one spring put back on the door.