Garage Door Won't Open? How to Diagnose the Fault by Symptom

A garage door that will not open may have a flat remote battery, a power problem, a lock left engaged or a mechanical fault. If the door is crooked, has a loose cable or appears to have a broken spring, stop using it. Do not pull the manual release or try to lift it; keep clear and arrange an inspection.

If the door looks undamaged, it is almost always one of a short list of faults, and you can usually narrow it down from a safe distance in a couple of minutes. This guide covers the six symptoms we get called out to most, what usually causes each one, and how to tell them apart without touching the mechanism.

Need help in Reading, Wokingham or the Thames Valley? Request a repair callback or call 0118 336 0212. Tell us if the door is stuck open or the car is trapped.

Start here: five checks that take two minutes

A fair number of the calls we take are solved by one of these before we ever get in the van. Work down the list in order.

1. Power to the operator. Check the normal power switch only if it is safely accessible, and note any power cut or tripped circuit. Do not open a fused spur or operator casing. If a circuit trips repeatedly, stop resetting it and have the electrical fault investigated. A light on the operator shows it has some power; it does not rule out every electrical fault.
2. Batteries, in both handsets. The most common cause of a door that "just stopped working" is a flat remote battery, and it often looks worse than it is: handsets bought together tend to fail within weeks of each other. Try the second handset, then try the wall button.
3. The manual release. Note whether it was used during a power cut or has been disturbed. A disconnected drive can run without moving the door. Do not pull the release to diagnose a fault, especially if the door is open or there is suspected spring or cable damage.
4. Locks and obstructions. Up-and-over doors have a handle lock and side latch bars that people forget they turned. Check the tracks for grit, screws and garden debris, and check the floor in front of the bottom seal in cold weather. Forcing the operator against a locked door bends the latch bars and turns a free fix into a repair.
5. The safety sensors, where fitted. Some doors use photocells across the opening; others have different safety arrangements. An object across a photocell beam can prevent closing. Clear only safely accessible obstructions and follow the manual's lens-cleaning instructions. Indicator lights and fault responses are model-specific; do not bypass protection.

What is safe to check, and what you must not touch

Almost everything on the list above is safe. The dangerous parts of a garage door are the ones storing the energy needed to lift it, and those parts stay loaded even when the door is shut and the power is off.

The counterbalance helps support the door's weight. Springs and lifting cables can remain under load, and damaged components can cause serious injury. Do not loosen brackets, adjust springs or handle a loose cable. These are jobs for a garage door engineer.

So: look, do not touch. If you can see a gap in the spring above the door, a frayed or slack cable, or one side of the door sitting lower than the other, stop using the door and arrange an inspection. Our guides to a snapped garage door spring and a snapped or loose garage door cable explain what to do next.

Find the fault by symptom

Once the five quick checks are done, match what your door is actually doing to the row below, then read the matching section.

What the door is doing	Most likely cause	Quick way to tell
Nothing at all, no motor noise	No power to the operator, or the door is locked	Does the operator's courtesy light come on when you press the wall button?
Opens partway and stops	Obstruction, worn roller, bent track, or a broken spring	Does it stop at the same point every time?
Very heavy, crooked, or drops	Broken spring or a snapped lift cable	Is one side sitting lower, or is there a gap in the spring?
Motor runs, door does not move	Door disengaged from the operator, or a failed drive	Does the chain or belt move along the boom?
Starts to close, then reverses	Photocells blocked, or the door is meeting resistance	Does it reverse at the same height each time?
Remote dead, wall button works	Battery, aerial, interference or lost pairing	Does a spare handset work from a safe position clear of the opening?

The door is completely dead

On a manual door, a lock, failed latch, jammed panel or counterbalance fault can prevent movement. Look for visible damage from a safe position. Do not force the handle, lift a heavy or crooked door, or put your hands near its lifting mechanism.

On an automated door with no visible damage, the operator's courtesy light can provide a clue. A light shows that some power is reaching the unit; it does not prove the power supply or controls are healthy. No response can have several causes, including a supply, control or operator fault. Follow the safe power checks above and leave electrical diagnosis to a professional.

Some wall consoles have a lock or holiday mode that disables the handsets. Check the instructions for your exact model before changing a setting. Avoid generic long-press or reset sequences: they can change programming or erase paired controls.

During a confirmed power cut, use manual operation only as described in your operator's manual, with the door fully closed and no suspected mechanical damage. Do not release an open, crooked or damaged door. If it will not move easily, stop and call an engineer. If your garage has no other entrance, discuss a suitable external emergency release before you need one.

The door opens partway and stops

Where the door stops is the most useful clue you have. In our experience it breaks down like this:

• Same point every time usually means something physical at that height: a bent section of track, a worn or collapsed roller, a dented panel catching, or debris in the track.
• A different point each time more often points to the operator, whose force settings and travel limits drift as it ages.
• Lifts a few inches, then comes straight back down is the classic sign of a broken spring. The operator hits its force limit almost immediately because it is trying to lift the whole weight of the door on its own. This is the most common version of the symptom, and it peaks in winter.

None of these is a reason to keep trying the door, and the pattern points an engineer in the right direction rather than proving the cause.

If the door lifts only a short distance, struggles or reverses, stop trying to operate it. Do not increase the operator's force setting to make it continue.

Do not disconnect and lift a door that is stopping unexpectedly to test its balance. Note where it stops, any noise and the operator's error code, then arrange an inspection. The engineer can separate a door-mechanism problem from an operator fault safely.

One seasonal note. Greases stiffen in the cold, and a rubber bottom seal will freeze to a damp concrete floor overnight. The operator senses the resistance and stops. That is a genuinely common January call and often needs nothing more than a service.

The door is heavy, crooked, or will not stay put

A door that feels unexpectedly heavy, sits crooked or moves on its own may have a counterbalance or other mechanical fault. Stop using it and arrange a professional inspection; these symptoms do not identify the failed component by themselves.

Do not carry out a lift-and-release balance test on a door showing these symptoms. Leave it in its current position, keep people clear and do not pull the emergency release. A door that is unexpectedly heavy or uneven needs a professional inspection.

Signs to look for, by eye only:

• A gap of two or three inches in the torsion spring on the bar above the door, in what should be a continuous coil.
• A visible break in another spring arrangement. Positions and mechanisms differ between door models.
• One side of the door sitting higher than the other. A damaged or displaced cable is one possible cause. Do not try to straighten the door; it may move unexpectedly.
• A cable that is frayed, or noticeably slack on one side while the other is tight.

A spring or cable fault can make the door unsafe and damage the operator if you keep trying to use it. Switch the operator off only if the normal power switch is safely reachable without approaching or going beneath the door. Do not pull the manual release or rely on the operator to support it. Read our snapped spring guide or cable repair guide for what happens next.

If you are wondering why now: torsion springs are typically rated for around 10,000 open-and-close cycles, with heavy-duty versions rated higher. In practice most springs we replace have done 10 to 15 years, because a damp garage corrodes a spring long before it runs out of cycles. A spring that goes after a decade of ordinary use has usually just worn out. Your door's maintenance schedule from the manufacturer is still the guide for inspections.

The motor runs but the door does not move

Describe what you noticed when the fault first appeared. Do not ask someone to cycle a faulty door while you stand near the mechanism.

The chain or belt moves but the door does not. The most common reason we find is that the manual release has been pulled, often during a power cut or by someone catching the cord, so the drive runs while the door stays put. Less often the trolley or its release catch has broken. Re-engaging differs by brand, so follow your exact operator manual, and only with the door fully closed and no suspected damage. Do not use a generic release or re-engagement sequence on a faulty door.

The motor whines but nothing on the boom moves. The drive has usually failed inside the head. On chain-drive operators the plastic drive gear is a known wear part, and a sheared chain or a snapped belt looks much the same from the ground. Stop trying the controls. It is an engineer's job, and often worth repairing rather than replacing, because the rest of the operator is frequently sound.

On a roller door, the drive arrangement depends on the model. Motor noise without curtain movement could indicate a drive or attachment fault. Stopping in the wrong position may involve travel settings, an obstruction or another mechanical or control fault. A curtain displaced from its guides also needs professional attention. Stop operating the door and describe what happened; do not adjust the limits to work around the symptom.

The motor hums but does not turn. On a mains-voltage motor, which means roller-door tube motors and older AC operators, that is usually a failed start capacitor or a seized motor. Most modern sectional operators run a low-voltage DC motor with no capacitor at all, where a hum without movement points at a jammed drive or a failing motor. Either way, stop trying it. Repeated attempts overheat the winding and turn a cheap part swap into a new operator.

The door starts to close, then reverses straight back

This is the safety system doing its job, so treat it as information rather than a fault to override. Something is telling the operator the way is not clear.

Photocells, where fitted. The most common cause by a distance. Look for anything crossing the beam (a wheelie bin, a box, a bike), check both indicator lights are on, and clean the lenses as your manual describes. Low winter sun shining straight into a lens can trigger it too, so if it only happens at one time of day, that is your answer. Sensors are knocked out of line by bins more than anything else; realigning them or chasing a loose wire is a job for an engineer.

Resistance in the travel. If the door meets friction, the operator reads it as an obstruction and reverses. Note the height at which it reverses, because that is where the resistance is. A collapsed roller, a bent track, a dry hinge or a frozen bottom seal are the usual causes.

The close limit set too low. The operator thinks the floor is lower than it is, so the door meets the concrete, senses resistance and backs off. The tell is that it reverses at the very bottom every time with no obstruction anywhere.

What not to do is wind the force setting up until the symptom disappears. Powered doors sold in the UK have to limit the force they can put into a person, and on a domestic operator that is normally delivered by the door backing off when it meets resistance. The standard behind it is BS EN 12453, and it is what a good installer force-tests at handover. Winding the force up raises how hard the door will push before it gives way, which is the one setting you do not want to be guessing at, and on an older operator that protection may be weak or absent to begin with. If your door needs more force than it used to, the right move is to find out why.

The remote does nothing but the wall button works

Good news first: if the door works normally from the wall button, the fault is most often on the radio side and is usually cheap to put right. Work through it in this order:

1. Batteries, in both handsets. Handsets bought together tend to fail together, which is why this so often looks like a motor fault.
2. Lock or holiday mode on the wall console. On many systems it disables the handsets while leaving the wall button live, which is exactly this symptom. Your model's manual shows how it is indicated.
3. Range. Try the handset from close by, standing clear of the opening. If it works close up but not from the drive, it is a range problem. If it does nothing even close by, the handset or its pairing has failed.
4. The aerial. Most operators have a thin aerial wire hanging from the motor head. If it has been tucked up, taped along the metal rail or cut during a tidy-up, range collapses. Look; do not pull on it.
5. Interference. LED lighting is the usual culprit. Turn the garage light off and try again; if the range comes back, you have found it.
6. Pairing. Handsets can lose their code after a power surge or an operator reset. Re-pairing uses a learn button on the operator and the sequence differs by brand, so follow the manual.

Avoid a factory reset as a first step, because it wipes every paired handset. A working wall button rules out most of the door, but not every operator fault, so if none of the above helps, an engineer can test the receiver. Our garage door remote control troubleshooting guide goes into each check in more detail.

Is this a repair or a replacement?

Nearly everything on this page is a repair, and usually an inexpensive one. The rule we use on site: if the door itself is sound, secure and reasonably straight, a repair in the £120 to £300 range beats a £2,000 replacement almost every time. The exception is a door needing repeated repairs, where the quotes start approaching a third of a new fitted door. We will tell you which side of that line you are on even when it means a smaller job for us.

A repair makes sense when the door is under 15 years old, the fault is mechanical (spring, cable, roller, motor), the panels are intact with no rust through, and parts for the model are still manufactured.

Replacement is the better call when several faults arrive at once (worn springs, tired cables, dry rollers and a failing motor together is a door telling you something), the panels are rusted through, dented through or warped, the door is over 20 years old with obsolete parts, or the door is mechanically fine but you want insulation, automation or better security. In that last case the fault is really an opportunity, and our 2026 garage door price guide sets out what a replacement actually costs. If you want to see the numbers move as you choose, you can design your garage door and build an itemised guide price as you go.

There is a useful middle option people often miss: a sound door with a dead operator. Automating or re-automating a good door is a much smaller job than replacing the whole thing, and we price it at survey.

What these repairs typically cost

Most garage door repairs land between £80 and £350 including the call-out. These are our typical 2026 figures, and you get a firm price on the spot once the fault is diagnosed.

Repair	Typical cost	Note
Spring replacement	£120 to £280	Full professional job including call-out
Spring and cable together	£200 to £300	Parts and any paired replacement depend on inspection and the manufacturer's requirements
Rollers and tracks	£80 to £120	Up to £180 if a track is bent
Electric opener faults	£100 to £250	Motor or circuit-board work on premium brands £150 to £250
Annual service	£80 to £150	Frequently prevents a £300 to £400 failure later

That last row is worth dwelling on. Most of the emergency call-outs we attend had a warning sign that had been there for months: a new noise, a door that had got stiffer, a bounce at the bottom of the travel. Full detail on what we check and what we charge is on our garage door repair and maintenance page.

If you need someone out

We diagnose a lot of faults over the phone, and it goes much faster if you have four things ready: what the door does when you press the button, any noise it makes, the door type (roller, sectional, up-and-over or side-hinged), and the brand on the operator if it is automated. Photographs taken from a safe position can help; do not move the door, climb beside the mechanism or go underneath it to take them.

We repair most makes and models across Reading, Oxford and the Thames Valley, including doors we did not fit, most repairs are scheduled within the week, and every repair carries a 5 year parts and labour guarantee. Call 0118 336 0212 or send us the details.

Safety note: the Health and Safety Executive's guidance on powered doors and gates sets out what obstruction protection has to do, not just stop when it meets something but back off far enough to release it. Health and safety law does not cover a homeowner's own garage door, but the engineering is identical, and a door that has lost that protection is a door to leave to an engineer. See the HSE guidance on powered doors and gates.

Frequently asked questions

Why will my garage door not open?

The most common causes, roughly in order, are a flat remote battery, no power to the operator, a manual release that has been pulled (often during a power cut), something blocking the safety sensors, a lock left on, or a broken spring. The first five can be checked from a safe position. A broken spring is the one dangerous item on the list: if the door is crooked, unusually heavy or has a gap in the spring, stop using it and call an engineer.

Why does my garage door open partway and then stop?

Where it stops is the clue. The same point every time usually means something physical at that height, such as a bent track, a worn roller, a dented panel or debris. A different point each time usually points to the operator's force or travel settings. If it lifts a few inches and comes straight back down, suspect a broken spring. In every case stop using it and do not turn the force setting up.

My garage door motor runs but the door does not move. What is wrong?

Most often the door has been disconnected from the operator by the manual release, so the drive runs while the door stays put. Re-engage it only as your operator's manual describes, with the door fully closed and undamaged. If the motor whines and nothing on the rail moves, the drive gear, chain or belt inside the head has failed and needs an engineer.

Why does my garage door reverse as soon as it starts to close?

The operator thinks something is in the way. Check for anything crossing the safety sensor beam, that both sensor lights are on, and for low sun shining into a lens. If the sensors are clear, the door is meeting resistance at the height where it reverses, usually a worn roller, a bent track or a bottom seal frozen to the floor. Never turn the force setting up to stop it reversing; that removes the safety protection.

Can I open my garage door manually during a power cut?

During a confirmed power cut, follow the operator manual only with the door fully closed and no suspected mechanical damage. Do not release an open, crooked or damaged door. If it will not move easily, stop and call an engineer.

Why does my garage door remote not work when the wall button does?

The fault is most often on the radio side. Check the batteries in both handsets, whether the wall console is in lock or holiday mode, the aerial wire on the motor head, and LED lighting interference by trying with the garage light off. If none of that helps, the handset may need re-pairing using your model's manual, or an engineer can test the receiver.

Why has my garage door suddenly become so heavy?

Usually a broken or weakened spring. The spring carries most of the door's weight, typically 40 to 80kg on a single steel door, so without it you are lifting the whole thing. Stop using the door, do not pull the manual release and call an engineer. Switch the operator off only if the normal power switch is safely reachable without going near or beneath the door.

Is it safe to use a garage door with a broken spring?

No. Without the spring, the full weight of the door bears on the cables, tracks and operator, and the door can drop. Stop using it, leave it in its current position and keep clear. Do not pull the release, lift the door or adjust springs or cables. A garage door engineer needs to make it safe and repair it.

How much does it cost to fix a garage door that will not open?

Most garage door repairs cost between £80 and £350 including the call-out. As a guide, spring replacement runs £120 to £280, a spring and cable together £200 to £300, rollers and tracks £80 to £120 (up to £180 if a track is bent), and electric opener faults £100 to £250. You should always get a firm price after diagnosis and before any work starts.

How quickly can a garage door that will not open be repaired?

Most repairs are scheduled within the week across the Thames Valley, and a door stuck open is treated as a priority because it is a security problem as well as an inconvenience. We carry common springs, cables and spares, so a straightforward job can often be finished on the first visit.