Why won't my commercial garage door open?

A commercial garage door that won't open is usually being held by something other than the motor. The most common causes are a broken spring or cable that leaves the door too heavy to lift, a lock or chain hoist interlock that cuts the controls, a STOP button, breaker or disconnect that is off, or a rolling fire door that dropped and has not been reset. Start with what the door does when you press OPEN, because that tells you where the problem is.

Start with what the door does

• Nothing happens at all. The operator is not getting power or a command, or an interlock is stopping it. See the checks below.
• The operator hums, clicks or strains, and the door barely moves. The door is likely too heavy, most often from a broken spring or cable. Stop pressing the button.
• The motor runs but the door does not move. The drive is not connected to the door. The manual release may be engaged, a drive chain may be off its sprocket, or a clutch may be slipping.
• The door lifts a little, then stops or goes back down. The operator felt too much resistance or its run timer ran out. A door that binds in its tracks or guides, or one out of balance, does this.
• The door is crooked, off track or hanging on one side. A cable or spring has failed on one side. Keep everyone out from under it.

When nothing happens at all

• The chain hoist is engaged. On hoist operators, pulling the disconnect chain trips an interlock switch that cuts the electric controls. If someone used the chain, set it back in its keeper so the controls work again.
• A lock interlock is closed. Many commercial doors have a slide lock wired to the operator so it cannot run while the door is locked. Open the lock fully.
• The STOP button or power is off. Check that the STOP button is not latched in, the disconnect switch is on and the breaker has not tripped. A three phase operator needs all three legs of power to run.
• The motor is too hot. A door that cycles all day can trip the motor's thermal overload. Let it cool before trying again.
• The control station or remote has failed. Try the wall station by the door as well as any remote or pull cord. If one works and the other does not, the fault is in that control.

When the door is too heavy to lift

The springs, not the operator, lift a commercial door. On a sectional door, torsion springs on a shaft above the door wind and unwind to balance its weight. On a rolling steel door, the springs sit inside the barrel the curtain rolls around. When a spring breaks or loses its tension, the full weight of the door falls on the operator, which then strains, stops on its force setting or runs without lifting the door.

Signs of a broken spring include a loud bang from the opening, a gap in a coil on the shaft, a door that feels far heavier than usual when it is released, or a door that opens a few inches and stops. A busy door wears out its springs much faster than a home door, so springs are a common reason a commercial door stops opening.

Broken garage door cables cause the same trouble, and often a crooked door too. The cables carry the lift from the springs to the bottom of the door. When one frays or snaps, that side of the door drops, the door can jam in its tracks and the operator cannot lift it evenly. A loose cable hanging beside the door or a door hanging lower on one side points to a cable.

Do not try to lift a door with a broken spring or cable by hand or with the chain hoist, and do not keep running the operator. LiftMaster's own manual warns that springs, cables and other door hardware are under extreme tension and should only be adjusted or repaired by a trained door technician.

When the motor runs but the door does not move

If you hear the operator run and nothing happens, the motor is turning but its drive is not reaching the door. On a trolley operator the trolley may have been released from the rail. On a jackshaft or hoist operator a drive chain may have slipped off its sprocket, a set screw may have come loose on the shaft, or the clutch may be slipping. A slipping clutch often goes with a door that has become hard to move, so a technician should check the balance as well as the drive.

When it is a rolling fire door

A rolling steel fire door is built to close on its own when its fusible link melts or the building's fire alarm releases it. Once it has closed, it will not open from the button until it is reset. DASMA's guidance on rolling fire doors calls for a drop test and reset by a trained person, and for the door to be checked every year. If a fire door came down without a fire, the release may have been set off by an alarm test, a power loss on some release devices, or a failed link. Do not wedge it open or tie the release. Call for the reset and a check.

What you can safely check

• Make sure the lock is open and nothing is blocking the door, the tracks or the guides.
• Check the STOP button, the disconnect switch and the breaker.
• Set the chain hoist or manual release back for motor operation.
• Look along the door for a broken spring, a loose cable, a crooked bottom bar or a door off its track, without touching any of them.
• In cold weather, look for a bottom seal frozen to the floor and clear the ice gently.
• Note the operator brand and model from its label and any blink code or alert light on it.

If the door must be opened before help arrives and the springs and cables look sound, see how to open a commercial roll up door manually. If it will not stay closed or secure afterwards, see why a commercial door will not close.

When to call for service

Call a commercial door technician when a spring or cable looks broken, the door is crooked or off its track, the operator hums or runs without lifting the door, a fire door needs resetting, or the door still will not open after the checks above. A door stuck shut on a loading dock or a shop is a lost day of work, and a heavy door that is forced can fall.

Common questions

Why is my commercial garage door clicking but not opening?

A click with no movement usually means the operator is trying to start but cannot. The cause can be a failed contactor, relay or control board in the operator, a lost leg of power on a three phase unit, or a door too heavy to lift because a spring broke. If the door feels much heavier than normal, treat it as a spring problem and stop using the operator. On a home opener, see why an opener clicks but the door won't open.

Why won't my LiftMaster commercial door open even though I use the wall switch?

If the wall station does nothing, check for a closed lock interlock, a chain hoist that is still engaged, a latched STOP button, a tripped breaker or a thermal overload. LiftMaster's Logic 5.0 commercial operators show a fault on their alert light, so note the blink count before you call. If the station works and only the remote fails, the remote or its receiver is the fault.

How can I open a commercial garage door from the outside?

Most commercial doors are opened by hand from the inside, with the chain hoist, a floor level disconnect or a lift handle on the bottom bar. Some have an outside key switch or a disconnect that can be reached from outside. If none can be reached and the door is locked down, call for service rather than prying the door.

Can a commercial door that won't open be fixed on the first visit?

Often, yes. Springs, cables, rollers and common operator parts are carried on our trucks, so many of these repairs are finished on the first visit.

How G Brothers helps

G Brothers repairs commercial doors across the Denver metro, including Denver, Lakewood, Golden, Arvada, Aurora and Commerce City. We service rolling steel, sectional, high-cycle and fire-rated doors, repair or replace trolley, jackshaft and hoist operators of every brand, and dispatch 24/7, with an average response of about an hour and a half. We can provide a certificate of insurance, usually within 24 hours. See commercial garage door repair, commercial garage door spring repair and roll up and rolling steel door repair, read what to do when a commercial door won't run on its operator or ask for a free estimate. A commercial maintenance plan catches worn springs and cables before a door stops opening.

Sources

• LiftMaster, Logic 5.0 Commercial Door Operators: Installation and Owner's Manual (interlocks, troubleshooting and safety warnings)
• Chamberlain, Commercial Door Operator Models MJ, MH and HMJ: Installation and Owner's Manual (manual operation)
• DASMA, Technical Data Sheet #271: Rolling Steel Fire Doors, Drop Testing and Annual Follow-Up
• DASMA, Technical Data Sheet #270: Recommended Rolling Door Maintenance Practices for Building Maintenance Supervisors