Why a garage door won't close
A door that refuses to come down is usually being stopped on purpose. Dominator says its openers stop and reverse when the door strikes something, and safety beams add an invisible line across the doorway. Merlin's myQ FAQ says that when the beams detect an object, the door will open but not close until the object is gone.
So the first job is finding whatever the opener thinks is in the way. Settings, limits and the door itself come after that.
Check the safety beams first
Clear the doorway
Move bins, bikes, boxes and hoses well back from the opening, inside and out, including anything sitting low between the two beam units.
Look at the lights on the beams
Merlin's MR855EVO manual says a flashing red light on a beam means its alignment is wrong, and that its fault code 1 then 4 means the sensors are misaligned or were blocked for a moment. It says to line both up until their lights are steady. If a beam has been knocked loose or its bracket is bent, leave it for the door specialist.
Count the opener's flashes
Press the wall button once and watch the main light. On Dominator's Smart Pro, Smart and Secure, 2 flashes mean a safety beam is stopping the door and 4 mean the battery in a wireless safety beam is low.
Use the emergency close if your model has it
Dominator's quick guide for the Smart Pro, Smart and Secure says that if a beam seems faulty, you can press and hold a pre-coded remote button until the door closes. Do it only with the doorway empty and nobody near the door.
Opener lights that point to a closing problem
| Opener | What the maker says it means | |
|---|---|---|
| 2 flashes of the main light | Dominator Smart Pro, Smart, Secure | A safety beam is stopping the door |
| 4 flashes of the main light | Dominator Smart Pro, Smart, Secure | Wireless safety beam battery low |
| 8 flashes of the main light | Dominator Smart Pro, Smart, Secure | The door was obstructed |
| 1 flash, then 1, 2 or 4 | Merlin MT3850EVO (up and down arrows) | Won't close: a safety beam problem |
| 10 flashes as the door reverses | Merlin MR855EVO | Check the obstruction detection beams |
| Red light flashing on a beam | Merlin MR855EVO | The beam is out of alignment |
Your opener's lights may differ
Flash counts belong to the model that shows them, and the same count can mean something else on another opener. Check yours against its own manual, and see the beeping and flashing guide for the other signals.
If you run the door from Merlin's myQ app, its FAQ says a blocked beam also makes the courtesy light flash 10 times and puts a CLOSE ERROR in the app.
Door closes part way, then reverses
With the beams clear and nothing under the door, think about the weather. Dominator's opener manual says very strong winds can push on the door and the tracks and sometimes trip the obstruction sensing while the door is moving. A door that misbehaves only on blustery days is worth mentioning at the next service rather than fighting with.
If it reverses on calm days too, the opener's force or travel settings, or a door that has started to bind, may be the cause. Dominator's service checklist puts travel limits, force and door alignment with the technician, so send the job rather than adjusting anything.
Never force it down or walk under it
Don't hold the door down, pull on it, or duck under a door that is moving. Dominator's opener manual warns that using the release while the door is open can make it fall fast if the springs are weak or broken or the door is out of balance. B&D NZ says not to stand in the door's path or walk through the doorway while it moves.
Garage door not closing all the way
A door that stops short of the floor, or touches down and goes straight back up, may have travel limits that are out. Dominator's manual puts the close limit at the point where the door first touches the ground, and warns against forcing the door into the floor because that can interfere with the manual release.
Limits are set at the opener, and Dominator's Smart Pro, Smart and Secure won't let them be set while running on battery backup. Leave that to the door specialist. A gap matters too: Merlin's MJ3800 manual says that if the gap under the closed door exceeds 6mm, the safety reversal may not work properly.
Won't close after a power cut or after pulling the release
Once the release has been used, the opener can run without the door following until the two are reconnected the way your manual shows. Until then Dominator warns that the door is not locked, which matters if it is stuck up overnight.
If the door was released while it was up and it feels heavy or wants to drop, don't try to wrestle it down: that points to the springs, and it is a door specialist's job. A power cut can also clear an opener's stored limits, and garage door won't open covers the Excel power test and the battery backup signals.
Garage door won't close automatically
Auto-close leans on the beams. Dominator's Smart Pro, Smart and Secure manual says it is compulsory to have safety beams installed when using Auto-Close mode, that the feature is off by default, and that it won't run if the door reversed after hitting something or stalling.
On the Excel roller door opener, Dominator's manual says auto-close tries to shut the door 30 seconds after it opens, and a door that opened automatically will not close automatically if the safety beam is fitted but not working correctly. Merlin's MT3850EVO also needs safety beams for its timer-to-close, and gives 8 seconds of beeps and flashing lights before the door moves. So a door that used to close itself and has stopped is worth a beam check first.
What to tell the door specialist
- The opener's brand and model
- Whether the door stops, reverses or won't start down at all
- The number of flashes, and any light on the beams
- Whether it happens only in strong wind or every time
- Whether auto-close or a phone app is set up
- Whether the door is stuck open now and the garage can't be secured
What you can do, and what to leave
You can
- Clear the doorway and the space between the beams
- Check the beam lights and count the opener's flashes
- Use Dominator's Safety Beam Emergency Close, where your model has it
- Note a low beam battery warning for the door specialist
Leave to a door specialist
- Setting travel limits and closing force
- Beams that are damaged, loose or won't stay lined up
- Fitting or rewiring safety beams
- A door that drops, binds or runs crooked
- Springs, cables and tracks
What we would do
Stand inside the garage, clear of the doorway, and watch both beam lights while someone else presses the wall button once. Note which light flickers or changes. That single press tells the door specialist whether they are chasing a beam, a setting or the door itself, before they arrive.