Garage Door Won't Open: A Troubleshooting Checklist (Try These Before You Call)

Before you call a technician: work through this checklist

About half of all "my garage door won't open" calls turn out to have a simple cause — one that doesn't require a technician at all. Work through these checks in order before scheduling a service visit. Each one takes 2–5 minutes.

1. Check the remote batteries. This is the single most common cause of a door that "won't respond." Replace them even if you think they're fine — remote batteries drain slowly and the last 20% of capacity can drop suddenly. Most remotes use CR2032 or AA batteries; your opener manual will confirm.
2. Try the wall button. If the wall button works but the remote doesn't, the problem is the remote (battery, programming, or a failed circuit board) — not the opener or door. If neither works, continue to step 3.
3. Check the outlet power. Plug a lamp or phone charger into the outlet your opener uses. No power? Check your breaker panel. Garages on older GFCI circuits may have a tripped outlet — look for a GFCI outlet on the garage wall with a "Reset" button and press it.
4. Check the safety sensors. Look at the two small devices mounted at the bottom of the door tracks, about 4–6 inches off the ground, one on each side. Both should have a steady indicator light (typically green on one side, amber on the other). If either light is blinking, the beam is broken — something is blocking the path, the sensors are knocked out of alignment, or a wire is loose. Clear the path, then gently nudge each sensor until both lights go solid.
5. Check the disconnect cord. If the red emergency cord was pulled (often accidentally, especially if something hit it), the opener is disconnected from the door. Re-engage by pulling the release cord toward the door until you hear a click, or manually slide the trolley back into the drive carriage.
6. Look for a lock mode / vacation mode. Many modern openers can be locked via a wall panel or app. If a keypad or panel shows a padlock icon, the opener may be in lock mode. Check your opener's manual or app settings.

If you've worked through all six steps and the door still won't open, you're likely looking at a mechanical issue — a broken spring, a failed drive gear, or an opener component failure. That's when to call a technician.

What each symptom usually means

The way your door fails tells you a lot about what's wrong. Here's a quick decoder:

• Opener motor runs, door doesn't move: Most likely a broken torsion spring (the motor can't lift 150+ pounds with no counterbalance) or a stripped drive gear inside the opener. Both require professional repair.
• Door opens partway then reverses: Safety sensor issue (beam is broken) or the opener's travel limit is set too short. Check sensors first. If sensors are fine, a technician can recalibrate limits in 15 minutes.
• Door moves very slowly or struggles: Spring tension is off (spring may be weakening or incorrectly set), or rollers need lubrication. Try lubricating the rollers and hinges with white lithium spray. If that doesn't help, a spring inspection is warranted.
• Door makes a grinding noise and barely moves: Likely a worn drive gear in the opener — a common failure mode after 8–10 years. This is a $100–$200 repair in most cases.
• Opener lights blink but nothing happens: This is usually the opener's error code. Count the blinks — most LiftMaster and Chamberlain openers use blink codes that map to specific problems in the manual.
• One side of the door rises higher than the other: Classic sign of a broken or loose cable, or a spring imbalance. Do not operate the door further — an off-balance door can jump the track.

What you should NOT try yourself

The checklist above covers legitimate DIY territory. Here's where to stop:

• Do not adjust or replace torsion springs. This requires specialized tools (steel winding bars) and carries real injury risk. See our spring replacement page for a full explanation of why this is one of the most dangerous home repairs. The cost savings versus professional service do not justify the risk.
• Do not try to manually force a door that is off its track. A door that has jumped the rail is under uneven spring tension. Forcing it can cause it to fall suddenly.
• Do not repeatedly try the opener if the door won't move. Running the motor against a stuck door strips drive gears, burns capacitors, and can bend the door panel. Two or three attempts to confirm the problem is enough — then stop.
• Do not attempt to adjust cable tension. Garage door cables are under spring tension and can snap if improperly handled.

When to call a technician — and what to tell them

If the DIY checklist above didn't solve the problem, it's time to call. When you do, have this information ready — it helps the technician show up with the right parts:

• The brand and model of your opener (usually on a sticker on the motor unit)
• Whether the motor runs when you press the button (hums or clicks vs. complete silence)
• Whether the door opens at all or is completely stuck
• Whether both safety sensor lights are lit solid or blinking
• The last time the door worked normally

Most opener repairs and spring replacements are completed in a single visit in the Germantown/Gaithersburg area. Same-day service is available most days, and evening/weekend coverage is included for urgent situations.