Can you replace just one garage door spring?
If your garage door has two springs and one breaks, DASMA advises replacing both. Here is the reasoning, what a technician checks, and what to avoid.
If your door has two springs and one has broken, the industry advice is to replace both. This guide explains why, and what a technician confirms before replacing them. Do not try to run the door or fit a spring yourself.
The short answer
DASMA, the Door and Access Systems Manufacturers' Association, says: if your door has two springs, replace both, even if one is not broken. That is the standard guidance for two-spring doors, and it is what we follow. Our technicians inspect the door and confirm the system before we replace anything.
This applies to doors that have two springs, either two torsion springs side by side on one shaft or an extension spring on each side. Some doors have a single spring, in which case there is only one to replace. If you are not sure what you have, see torsion vs extension springs.
The same logic applies when a door is old, or when the spring that broke looks rusted. The unbroken spring is usually in the same condition. Seeing one intact coil does not tell you it has much life left.
Why replace both
Reasons given by DASMA and by service companies that publish on the topic:
- They age together. Both springs have lifted the same door the same number of times. One broke first, but the other is at a similar point in its service life. One service company says the surviving spring typically fails within a few months. We could not confirm that timeframe from a standards body, so treat it as an installer's observation, not a rule.
- They are meant to work as a pair. The two springs share the load of counterbalancing the door. A new spring beside an old one can leave the pair unevenly matched.
- It prevents damage. DASMA says replacing the second spring prevents damage if it later fails and keeps the door running efficiently.
- It avoids a second visit. If the old spring fails later, you face the same problem again, with the door stuck.
A door with one spring gone is also under uneven load. Running it on the opener can strain the opener. For why springs fail in the first place, see why garage door springs break.
Replacing both also means the two new springs can be set up together as a matched pair for your door. A technician sizes them to the door, so the pair carries the door's weight evenly and the opener is not asked to make up the difference. If you add up a second call-out and the risk of a second sudden failure, replacing both in one visit is the more sensible repair.
What a technician confirms before replacing
A replacement pair is not a generic part. DASMA says installers should confirm spring identification and parameters against the door manufacturer's instructions. In practice, our technicians:
- Inspect the door and confirm which spring type and how many springs it has.
- Check the cables, drums or pulleys, brackets and bottom fixtures for damage, since a spring failure can damage nearby parts.
- Measure the door and establish its weight, because the spring has to match the door.
- Replace the springs and set the tension for that door.
- Check that the door is balanced before it goes back into use.
Spring color codes alone are not a reliable identifier. DASMA says they should be backed up by physical measurements of the spring, door weight and other information, especially on older installations. See what a spring replacement visit involves.
What you can safely check
From the floor, with the door at rest, look only:
- Count the springs you can see. Two on a bar above the door, or one on each side, means a two-spring door.
- Note whether the unbroken one looks worn, rusted, stretched or has a gap forming.
- Take a photo of the spring area, any labels, and the ends of the springs.
- Look at the cables at the bottom corners for fraying.
Do not operate the door to see which spring is broken. A door with a broken spring is heavy and can drop. Do not touch the springs, cables or brackets.
When to stop and bring in a technician
Bring in a technician when:
- You heard a bang, or the door will not lift or stay open. See signs a spring is broken.
- One spring is visibly broken or separated.
- The unbroken spring is rusted, stretched, or shows any gap.
- You are tempted to buy one spring and swap it yourself.
Do not replace a spring yourself
DASMA says spring replacement should only be performed by a trained door systems technician. Springs are under dangerous tension. A single spring bought online and fitted without the right tools and training is a common route to injury.
We replace springs on residential garage doors. See spring replacement for what the service covers and garage door repair for related work.
Related services
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Need a technician?
If something on your door looks damaged, stay clear and let a technician handle it.
Questions and answers
Is replacing both springs just an upsell?
No. It is DASMA's published advice for doors with two springs. The reasoning is that the second spring has the same wear and fails sooner or later, and that a matched pair keeps the door running properly.
My door has one spring. Do I need two?
Not necessarily. Some doors are built with a single spring. A technician measures the door and confirms what it needs. Do not add or remove a spring yourself.
Can I just replace the broken one and see how it goes?
That is not the advice DASMA gives. If the other spring then fails, you have a second breakdown and another technician visit. We recommend replacing both on a two-spring door.
Do the cables need replacing too?
Not always. A technician inspects the cables for fraying and wear as part of the visit and replaces them if needed. Cables are under spring tension and are technician-only work.
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