Garage Door Won’t Open? 8 Things to Check Before You Call
By Denver Garage Door Ltd — BBB accredited, serving Denver metro since 2011. Last updated: April 2026.
If your garage door won’t open, it’s either refusing to budge at all, moving an inch and reversing, or acting weird with the remote. Most of the time the fix is something simple you can handle yourself — a dead remote battery, a misaligned sensor, a tripped breaker. Occasionally it’s a broken spring or cable, in which case you should stop trying and call us. This guide walks through the 8 most common causes in the order we check them, plus when to stop DIY and get a tech out.
1. Check the Remote and Keypad Batteries
Sounds silly but it’s the #1 call. Remote batteries die, and modern openers with rolling codes and LED indicators can give the remote more work to do than the old analog ones. Pop the battery, try the wall button — if the wall button works, it’s a remote issue, not an opener issue. Same goes for the wireless keypad: dead 9-volt battery is the most common cause of a non-responsive keypad.
Still stuck after the checks? Call (303) 335-5102 — same-day Denver diagnosis, free if you book the repair.
2. Look for Blinking Lights on the Opener
Most modern openers blink a fault code when something’s wrong. LiftMaster blinks 1–5 times, Genie does a similar pattern. Count the blinks and look up the code online (or call us with it). This is the fastest path to a diagnosis, and if you call us with the blink count we’ll often show up with the exact part you need.
3. Are the Safety Sensors Aligned?
Those two small photo-eye sensors at the bottom of each track have to see each other. If they’re knocked out of alignment — kid hit one with a scooter, lawn mower bumped it, dog ran into it — the door will refuse to close, and on some models it refuses to open as well. Look at the LED on each sensor: if one is blinking or dark, alignment is off. Wipe the lenses and nudge them until both lights are solid. Our dedicated sensor alignment page covers the fix in detail.
4. Check for a Tripped Breaker or GFCI
If the opener is completely dead (no lights, no hum), check the breaker panel and the outlet the opener plugs into. Garages often run on a GFCI outlet that can trip during a storm. Reset and try again.
5. Is the Door Disengaged from the Opener?
That red cord hanging from the trolley disconnects the door from the opener chain/belt. If someone pulled it — or it got pulled accidentally — the opener runs but the door doesn’t move. Reconnect by pulling the cord back toward the door and running the opener through a cycle. You’ll hear the trolley re-engage.
6. Listen for a Broken Spring
If you heard a loud bang recently — like a gunshot from the garage — that’s a broken torsion spring. The opener might try to lift but the door barely moves or goes crooked. Stop using the opener immediately. Lifting a heavy door with the opener’s motor alone will burn out the motor. Call us for same-day spring replacement. This is also a good time to revisit our dedicated garage door spring service page.
7. Check the Cables
If a cable snaps, the door usually becomes crooked on the tracks — one side drops. Don’t force it. Forcing a door with a snapped cable can bend the tracks and turn a $150 job into an $800 job.
8. Frozen to the Floor
Denver-specific and very common in winter: the bottom seal freezes to the concrete floor. The opener thinks there’s an obstruction and stops. Pour warm (not boiling) water at the seal or use a heat gun on low, then try again. If the bottom seal is cracked or curled, this will keep happening all winter — replacement is easy and cheap.
When to Stop DIY and Call
Three situations: a broken spring (loud bang, crooked door, very heavy to lift), a snapped cable (door crooked, one side dropped), or any time the door is clearly off its tracks. These are not DIY jobs — torsion springs in particular store enough energy to seriously injure you. Call (303) 335-5102 and we’ll come out same-day.
Still Stuck?
If the basic checks didn’t fix it, it’s likely an opener logic board, a worn drive gear, or a failed capacitor. Those need a tech. Brand-specific pages: LiftMaster, Genie, Craftsman, Linear. Full lineup at opener brands hub.
Frequently Asked Questions
Why does my door open but not close?
Almost always the safety sensors. Check alignment first — tiny nudges, both lights solid green.
Why does the door go up an inch and come back down?
Opener force/travel limit needs adjustment, or sensors are triggering a reverse. A tech can adjust in 15 minutes.
Can I force the door up with the opener if there’s a broken spring?
No — you’ll burn out the opener motor. Call for same-day service.
My opener is old and parts aren’t available. What now?
Time to replace. Modern belt-drive openers are much quieter and come with security upgrades. See our opener repair and installation page.
Do you charge a diagnostic fee?
Only if you pass on the repair. Fees are waived if you book the work. See our cost guide.
Need help now? Call (303) 335-5102 or book online. Service across Central, East, South, and West Denver.