Spring replacement
The spring does the lifting, not the opener. When one breaks you hear it: a bang from the garage like something fell over, then a door that the opener cannot budge and that you cannot lift by hand. Around Boise the call comes in waves after hard cold snaps, because a tired spring picks a below-freezing morning to let go.
How do you know it is the spring?
- A loud bang from the garage, then a door that will not open
- The opener strains, lifts a few inches, and reverses or quits
- A visible gap in the coil on the shaft above the door on a torsion setup
- The door drops hard when you pull the release and try it by hand
Should you replace both springs?
If the door has two, yes. Both springs have counted the same cycles, so the surviving one is weeks from the same failure, and a second service call costs more than doing them together. This is also where the quote conversation belongs: a company should tell you the spring size it is installing and that the door gets rebalanced, not just swapped.
Why is this the one to not do yourself?
A wound torsion spring stores enough energy to break bones. The winding bars, the set screws, and the technique are the whole job, and the people who get hurt are the ones who had almost the right tools. Every other repair on this site you could reasonably attempt; this one is the exception the pros exist for.
What does the job cover?
Measure the door weight and drum, match the spring, wind out the old one, install and tension the new pair, then balance the door so it holds at any height. A door that does not stay put halfway up is not finished.