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, the checks below can help you describe the problem without dismantling anything. Match the symptoms to the relevant section and follow the instructions for your door and operator.

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.

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

The stopping point is useful information, but it does not identify the fault by itself. An obstruction, damaged roller or track, counterbalance problem, safety-device fault or operator problem can interrupt travel.

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.

Spring life and inspection intervals depend on the particular door and how it is used. Follow the manufacturer's maintenance schedule; a generic cycle count does not tell you whether your spring is safe.

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 drive may be disconnected or there may be a fault with the trolley or coupling. Follow the exact operator manual only if the door is fully closed and there is no suspected mechanical damage. Do not use a generic release or re-engagement sequence on a faulty door.

The motor whines but nothing on the boom moves. A drive, gear, chain or belt fault may be responsible. The noise alone cannot establish which part has failed or whether the rest of the operator is sound. Stop trying the controls and have an engineer diagnose it.

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. Check for a safely accessible object across the beam and follow the manual for cleaning and interpreting lights. Misalignment, wiring faults or direct sunlight can affect some sensors. Leave electrical and alignment repairs to 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

If the door moves normally from the wall control, compare a spare handset and check the correct battery type for the remote. Then consult the operator manual for any radio lock setting. Reduced range can also point to interference, while a handset that has never worked may be incompatible.

Do not begin with a factory reset or assume a working wall button rules out every operator fault. Our garage door remote control troubleshooting guide gives the checks in order, including compatibility, pairing and when to call an engineer.

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.

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?

Possible causes include a flat remote battery, no power, a lock left engaged, a disconnected drive or a mechanical fault. Check for visible damage first. If the door is crooked or has a loose cable or suspected broken spring, stop using it and arrange an inspection.

Why does my garage door open partway and then stop?

The stopping point can help an engineer diagnose an obstruction, mechanical resistance, a counterbalance problem or an operator fault. It does not identify the cause by itself. Stop using a door that struggles, stops unexpectedly or moves unevenly; do not change its force settings.

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

A disconnected drive or a drive fault may be responsible. Do not pull the release or try a generic re-engagement sequence. Follow the exact operator manual only if the door is fully closed and undamaged; otherwise arrange an inspection.

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

An obstruction, resistance, safety-device fault or incorrect adjustment may be responsible. Where photocells are fitted, check for a safely accessible obstruction and use the model manual to interpret indicator lights. Do not increase force settings or bypass protection; arrange an inspection if the fault persists.

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?

A handset battery, radio lock setting, interference, programming issue or receiver fault may be responsible. Compare a spare remote and check the exact model instructions before resetting anything. A working wall button does not prove that every part of the system is healthy.

Why has my garage door suddenly become so heavy?

A spring, cable or other mechanical fault may have affected the counterbalance. Stop using the door, do not pull the manual release and arrange an inspection. Switch off the operator only if the normal power switch is safely accessible without approaching or going beneath the door.

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

No. 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. Arrange a garage door engineer to make it safe and repair the fault.

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.