Why won't my commercial garage door close?

A commercial garage door that won't close is most often stopped by its safety system, not a broken motor. When a monitored photo eye or reversing edge is blocked, out of line or unplugged, a modern commercial operator will not close from a button press, a remote or a timer. It only closes while someone holds the CLOSE button. The other usual causes are a lock or chain hoist interlock that cuts the controls, limits or a run timer that stop the door short, and a door that binds or is out of balance. Start with what the door does when you press CLOSE.

It only closes while you hold the button

This is the most common reason, and it means the safety system is doing its job. UL 325, the safety standard for door operators, requires every commercial door operator to either close only by constant pressure on a control mounted in sight of the door, or to have a working, monitored entrapment protection device, such as a photo eye or a monitored edge on the bottom of the door. If the operator can also be closed by a three button station, a remote or a timer to close, the device has to be connected and working.

So when the photo eyes are blocked, knocked out of line or disconnected, the operator falls back to hold to close. On a LiftMaster Logic 5.0 operator this is called restricted close mode: the door opens normally but closes only after you hold CLOSE for about five seconds. A flashing light for the safety device on the board, or seven blinks on the maintenance alert light, points to the photo eyes or edge.

What to check:

• Look for anything in the beam: a pallet, a box, a hose, snow or a spider web on the lens.
• Check that both photo eye brackets are tight and the lenses face each other. Forklifts and carts bump them out of line often.
• Wipe the lenses with a dry cloth.
• Look along the wire for a cut or a pulled connection, especially where it runs down the door jamb.
• On a door with a sensing edge on the bottom, look for a torn or crushed edge or a damaged coil cord.

If the eyes look fine and the door still only closes on constant pressure, the eye, the edge or its wiring has likely failed, and a technician needs to test it.

It starts down, then goes back up

A door that reverses on the way down sensed something. The photo eye beam was broken, the bottom edge touched something, or the operator felt more resistance than it expected. On a LiftMaster Logic 5.0, four blinks on the maintenance alert light mean an obstruction was sensed while closing.

• Clear the opening and watch the photo eye lights while someone runs the door.
• Look at the guides or tracks for bent sections, ice or debris that would make the door bind.
• On a rolling steel door, look for a slat that has slipped sideways or a curtain that drags in one guide.
• If it reverses only in cold weather, the bottom seal may be frozen to the floor or the door may have grown stiff in the guides.

A door that reverses with nothing in the way can be out of balance. LiftMaster's own manual warns that an improperly balanced door may not reverse when it should, and that springs, cables and other hardware should only be repaired by a trained door technician. Do not keep cycling a door that strains.

It does nothing at all

If the door will not respond to any button, the operator is not getting a command or not allowed to act on one.

• The chain hoist is engaged. On hoist operators, pulling the disconnect chain trips an interlock switch that cuts the electric controls. If someone opened the door by chain, release the disconnect chain from its keeper so the controls work again.
• A lock interlock is open. Many doors have a slide lock wired to the operator so it cannot run while the door is locked. Make sure the lock is fully open.
• 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. Three phase operators need all three legs of power.
• The motor is too hot. A thermal overload can trip on a door that runs constantly. Let it cool before trying again.

It stops partway down

A door that stops short of the floor can have limits that need resetting, often after work on the door or a power problem. Commercial operators also have a maximum run timer that stops the door if it runs longer than expected. A door that has started to bind or drag runs slower, hits that timer and stops. On a LiftMaster Logic 5.0, three blinks mean the run timer timed out. Two blinks mean the operator lost its speed sensor signal, which can be a slipping clutch, and the door will only answer constant pressure commands until that is fixed.

Never bypass the safety devices

It can be tempting to jumper the photo eye terminals or tape over an edge to keep a busy door running. Don't. The sensors and edges are what keep the door from closing on a person, a vehicle or a load, and LiftMaster states the monitored device must not be disabled on the wiring types that use it. Holding CLOSE in sight of the door is the safe way to keep the opening usable until the device is repaired. If you need the door shut and it will not run at all, see how to open or close a commercial roll up door manually with the chain hoist or the floor disconnect.

When to call for service

Call a commercial door technician when the photo eyes or edge still fault after you clean and line them up, the door reverses with nothing in the way, a spring or cable looks broken, the door is crooked in its tracks or guides, or the door has to be secured and will not close. Note the operator brand and model from its label and any blink code before you call. It speeds up the repair.

How G Brothers helps

Operators are the most common job in our commercial records, and we repair or replace trolley, jackshaft and hoist operators of every brand, along with their photo eyes, edges and wiring. We service rolling steel, sectional, high-cycle and fire-rated doors across the Denver metro, dispatch 24/7 for doors that will not close or secure, and can provide a certificate of insurance, usually within 24 hours. See commercial garage door repair, commercial garage door operators 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 spring and balance problems before a door stops.

Sources

• LiftMaster, Logic 5.0 Commercial Door Operators: Installation and Owner's Manual (entrapment protection, troubleshooting guide and error codes)
• DASMA, Ask Joe: Entrapment Protection on Existing Commercial Door Operators (Door + Access Systems, Spring 2015)