What a Broken Spring Actually Does to the Door
A torsion spring stores the energy that lifts the door. When it snaps, that counterbalance disappears. The door becomes dead weight — 150 to 300 pounds for a typical residential double — and the opener, the cables, and the track are not designed to carry it alone.
If the spring breaks while the door is closed, the opener will either stall at the floor or strain until the motor overheats and trips its thermal cutout. You will hear a loud bang — the spring releasing its tension in a fraction of a second — followed by a humming motor that goes nowhere.
If it breaks while the door is open, the door can crash down the moment the opener releases or the safety sensors are interrupted. That is the scenario that sends people to the emergency room.
Extension springs, the ones that run parallel to the horizontal tracks on older single-car doors, behave differently. When one breaks, the other is still stretched. The door lifts crooked, jams in the track, and the remaining spring can whip loose if the cable comes off the pulley. Both systems are dangerous. Neither is safe to operate.
How to Tell Which Spring System You Have
Look above the door opening. A torsion spring sits on a steel shaft directly over the centre of the door, wound tight between two stationary cones. You will see one spring (common on 8- to 10-foot doors) or two springs with a centre bearing plate (standard on 16-foot doubles).
Extension springs run along the horizontal tracks on each side. Each spring has a safety cable threaded through its centre — or it should. If you see no safety cables, the previous installer skipped a critical safeguard. When that spring breaks, the metal coil becomes a projectile.
In the Burnaby Southslope and Edmonds neighbourhoods, most 1970s split-levels and ranchers still carry their original torsion hardware. Those springs are past their rated 10,000-cycle life. In Coquitlam’s Austin Heights, split-levels from the same era show the same pattern. In New Westminster’s Sapperton, compact single-car garages often run extension springs on 7-foot doors — lighter doors, but the same failure mode.
What You Can Check Without Touching the Spring
Stand inside the garage with the door closed. Pull the red emergency-release cord so the trolley disconnects from the opener carriage. Lift the door manually to about waist height and let go.
A balanced door stays put. A door with a broken torsion spring will feel heavy immediately — 150-plus pounds of dead weight — and will want to slam down. A door with a broken extension spring will hang crooked, one side lower than the other, and may bind in the track.
Do not try to hold it up. Do not prop it with a 2×4. If the door moves on its own, the counterbalance is gone. Close it gently if you can, lock it in the down position, and leave the opener disconnected.
Check the cables while you are there. A broken torsion spring often throws the cable off the drum. You will see slack cable hanging in a loop, or the cable wrapped around the shaft in a birds-nest. Either way, the cable is no longer doing its job. Do not touch it. A cable under even partial tension can cut to the bone.
The Line Where DIY Stops
Replacing an extension spring on a single-car door is within reach of a careful homeowner who understands the geometry: secure the door open with C-clamps on the track, remove the old spring, install the new one with the safety cable threaded through, and re-tension to the manufacturer’s spec. The spring is not under load while the door is open.
Torsion springs are different. They are wound tight while the door is closed. The stored energy in a wound torsion spring on a 16-foot double door is enough to shatter a winding bar, break an arm, or kill you if the bar slips or the cone fractures. Professionals use calibrated winding bars, not screwdrivers or pipe wrenches. They stand to the side, not in the plane of the spring. They know the turn count for your door weight, height, and drum size.
If you have a torsion system, you do not touch the spring. You do not touch the centre bearing plate. You do not touch the cables on the drums. The only safe action is the manual balance test described above, then calling a technician.
What the Technician Does on the Call
The tech verifies the spring is broken — not a seized bearing, not a stripped opener gear, not a cable off the drum. They measure the door weight, height, track radius, and drum circumference. They calculate the correct wire size, inside diameter, and length for the replacement spring. Guessing by eye is how you end up with a door that opens too fast, closes too hard, or burns out the opener in six months.
They unwind the broken spring (or the remaining spring on a two-spring system) with winding bars, remove the hardware, install the new spring, wind it to the calculated turn count, set the set screws, and test the balance. Then they lubricate the bearings, rollers, and hinges, check the cable drums for wear, and run the opener through a full cycle.
On a two-spring system, they replace both. The second spring has the same cycles on it. Leaving it saves fifty dollars in parts and costs you a second service call inside a year.
In Queens Park, New Westminster, the door openings are often non-standard — 8-foot-6, 9-foot-2, custom widths to match heritage façades. Off-the-shelf springs do not fit. The tech has to order cut-to-length wire or fabricate on a mobile winder. That adds a day to the repair. In Burke Mountain, Coquitlam, the builder-installed doors are still under warranty. The conversation there is about whether the manufacturer covers the spring or whether the repair voids the door warranty. Different neighbourhood, different constraint.
What a broken garage door spring repair costs in BC
Spring wire size, inside diameter, and length determine the part price. A standard 2-inch inside-diameter torsion spring for a 7-foot residential door runs one range. A 2.625-inch ID for a high-lift commercial door runs another. High-cycle springs — rated 25,000 or 50,000 cycles instead of 10,000 — cost 30 to 50 percent more in wire but last three to five times longer. If you plan to stay in the house, they pay for themselves.
Labour is the larger variable. A straightforward single-spring swap on a standard 16-foot double takes 60 to 90 minutes. A two-spring conversion on a door that originally had one spring takes longer — new centre bearing plate, new drums, possibly a longer shaft. A custom-sized spring for a heritage opening in Queens Park adds ordering time and a return trip.
Emergency after-hours calls carry a premium. So does a door that has come off track because the broken spring let it crash down. Bent tracks, damaged panels, and shredded cables turn a spring job into a half-day rebuild.
How to prevent garage door springs from breaking again
Cycle count is what kills springs, not calendar years. A 10,000-cycle spring on a door used four times a day — two cars leaving, two returning — lasts about seven years. Same spring on a door used twice a day lasts fourteen. The math is that simple.
If you are replacing a spring, ask for high-cycle wire. The incremental cost is small compared to the labour, which stays the same. Lubricate the spring coils twice a year with a non-sticky PTFE spray — not WD-40, not grease. Grease collects grit and accelerates wear. PTFE lets the coils slide against each other as they wind and unwind.
Check the cables every season. Frayed strands at the bottom bracket or the drum mean the cable is next. Replace it before it snaps. A broken cable with a good spring still drops the door.
If you live within a kilometre of the Fraser River — Steveston, Queensborough, parts of Port Coquitlam’s older core — salt air accelerates corrosion on the spring wire and the cable strands. Wash the hardware with fresh water twice a year. Spray the springs with a corrosion inhibitor rated for marine environments. It buys you cycles.
Book a garage door spring repair in Metro Vancouver
Disconnect the opener. Do not operate the door. Call 778-873-7282. We will verify the spring, quote the correct replacement, and have the door balanced and safe the same day.