Awning Arms Won't Close All the Way? Causes, Fixes and Safety
When lateral awning arms will not fold fully, the roller has usually stopped turning before the arms are closed (a motor limit or crank issue), or something is physically stopping the arms (crossed arms, a misaligned shoulder, a binding elbow, debris or an oversized fabric roll). The fix ranges from a two-minute limit adjustment to replacing an arm. This page helps you tell which, and keeps you clear of the spring energy stored in the arms while you work.
Key takeaways
- First decide whether the roller is still trying to turn. If the motor stops cleanly with the arms open, it is almost always the upper limit. If the motor strains or the crank goes stiff, something is blocking the arms.
- Arms that cross or clash near closing are a geometry problem (arm length versus awning width, or shoulder pitch), not a lubrication problem.
- A gap of 1/2 in (13 mm) or more between the front bar and a full cassette lets rain, leaves and wasps in, and lets wind get a grip. It is worth fixing.
- Never force the last inch with a crank extension or by pushing the front bar. Gearboxes and arm cables fail that way.
- Lateral arms push outward even when closed. Strap them before touching shoulders, elbows or the front bar connection.
Fast diagnosis
Run the awning out about 3 ft (1 m) and back in while you watch the arms from below and from the side. Note exactly where it stops and whether it stops cleanly or with strain.
| Symptom | Likely cause | Difficulty |
|---|---|---|
| Motor stops cleanly, front bar 1-6 in (2-15 cm) short of the cassette | Upper limit set too early or drifted | Easy |
| Motor stops with a hum or click, arms almost closed | Obstruction, or motor torque sensing tripping on a stiff arm | Easy to moderate |
| One arm folds, the other stays slightly open | Binding elbow, weak spring on the other arm, or shoulder pitch mismatch | Moderate |
| Arms collide or one rides over the other when folding | Arm crossover on a narrow awning, or shoulder rotated | Moderate to pro |
| Arm hits the cassette or bracket before folding flat | Shoulder pitch changed so the arm meets the housing at an angle | Moderate |
| Front bar closes at one end, gap at the other | Coned fabric roll, unequal pitch, or bent front bar | Moderate |
| Arm hangs loosely or elbow drops when closing | Broken arm cable, belt or chain | Pro |
| Crank goes stiff in the last few turns | Roll too fat for the cassette, or gearbox at its end stop | Moderate |
If the awning will not move inward at all, that is a different fault: see awning won't retract. If the motor makes no sound, start with motor troubleshooting.
How the arms are supposed to close
A lateral arm is a folding strut with a strong spring inside the upper arm. The spring pulls a cable, belt or chain that wraps around the elbow, which pushes the forearm open. Retracting the awning means the roller winds the fabric in, the fabric pulls the front bar back, and that pull overcomes the springs and folds the arms. The arms do not close themselves; the fabric tension does it. So anything that stops the roller early, or that adds resistance in the last part of the fold, leaves the arms open. The detail of spring and elbow design is in how lateral arm springs work and arm elbows: cable, belt and chain.
Fixes, from easiest to hardest
1. Clear obstructions (free)
Look along the cassette lip, the front bar and the arm channels. Leaves, wasp nests, dropped clips, and a valance that has flipped over the front bar can all hold the last inch open. In winter, ice between the front bar and cassette does the same: wait for a thaw rather than running the motor against it.
2. Reset the upper limit on a motorized awning (free, 10 minutes)
If the motor stops cleanly with the arms open, the upper end limit is set too low. Limits drift slightly over time, after a power outage on some electronic motors, or after fabric replacement changes the roll diameter. On a Somfy RTS motor or similar radio motor, the usual approach is to enter limit-adjustment mode from the programmed remote and nudge the upper stop. Mechanical-limit motors have two adjustment screws on the motor head, marked with arrows. Adjust in small steps, and stop when the front bar seats lightly without the motor straining.
3. Lubricate and free the elbows (low cost)
A stiff elbow pivot adds resistance exactly where the fold is hardest. With the awning extended about two thirds, spray a dry PTFE or silicone lubricant into each elbow pivot and the shoulder pivot, then cycle the awning five or six times. Avoid grease or general purpose oil, which collect grit and get stiffer in cold weather. If an elbow squeals or grinds rather than just being stiff, see awning noises; a damaged elbow bushing may need replacement.
4. Even out the arm pitch (moderate)
Each arm shoulder has a pitch adjustment, usually a bolt or threaded rod that tilts the shoulder relative to the torsion bar. If one arm is set at a steeper angle than the other, it reaches the cassette at a different point, and either that arm or the front bar end hits the housing before the other side closes. Measure the front bar height at both ends at full extension. If they differ by more than about 1/2 in (13 mm), correct the low side using the method in our sag and pitch guide. For a front bar that sits low on one end, also read awning one side lower.
5. Fix arm crossover on narrow awnings (moderate to pro)
On a standard lateral arm awning the folded arms lie side by side along the cassette. If the arms are longer than about half the awning width, they overlap when folded and must be mounted at slightly different heights so one passes over the other. If a shoulder has rotated or been re-pitched, the arms meet instead of passing. The signs are scuffed arm covers in the middle and a clunk when closing.
6. Reduce an oversized fabric roll (moderate)
On a full cassette, the space for the rolled fabric is tight. A coned roll, fabric that was rolled up with creases, or a replacement cover that is thicker or longer than the original can make the roll too fat to let the cassette close. Measure the roll diameter at both ends. If one end is fatter, follow fabric rolls unevenly. If the new fabric is simply longer than original, it needs shortening at the roller end.
7. Replace a broken arm cable, belt or arm (pro)
If an arm hangs loose, drops at the elbow, or the forearm wobbles side to side, the internal cable, belt or chain has failed or stretched. Some arm designs allow the belt to be replaced; many are replaced as a complete arm. Because the arm must be fully de-tensioned, this is work for a trained technician unless the manufacturer provides a specific DIY procedure and tools.
When to call a pro
- An arm is loose, hanging, or has a frayed or broken cable or belt visible at the elbow.
- A wall bracket or shoulder has moved, cracked, or is pulling away from the wall.
- Arms are colliding and you do not know the factory offset.
- The front bar or an arm is bent after wind.
- You would need to unbolt an arm, shoulder or front bar connection.
A gap at the cassette on a new awning is frequently an installation or limit setting issue and is often covered. Check your warranty terms before paying for a call-out.
Frequently asked questions
Is it safe to leave the awning slightly open if the arms won't close?
For a day or two in calm weather, yes. Long term it is not: wind can catch the gap and pull the front bar, water and debris collect in the cassette, and the fabric edge is exposed to UV. Fix it before the next storm or before winter.
Can I push the front bar closed by hand?
Lightly guiding it while the motor or crank runs is fine. Pushing hard against the arm springs does not fix anything, can pinch fingers between the front bar and cassette, and strains the gearbox or motor.
Why did the arms start stopping short after I replaced the fabric?
New fabric is often slightly thicker or longer than the worn original, so the roll ends up a different diameter and the motor's upper limit arrives at a different point. Re-set the upper limit. If the roll is too fat to fit the cassette, the fabric may need trimming at the roller end.
How much gap at the cassette is acceptable?
On a full cassette the front bar should seat with no visible gap or close to it. On open or semi-cassette awnings, a small gap of 1/4 in (6 mm) or so is harmless as long as both ends match. Anything uneven suggests a pitch or roll problem.
Do manual crank awnings have limits too?
No electronic limits, but many gearboxes have a mechanical end stop, and you can overcrank past the closed point. If the crank gets very stiff near closing, stop rather than forcing it. Our crank troubleshooting guide explains why.
Will a wind sensor close the awning if the arms are sticking?
A wind sensor commands the motor to retract, but it cannot overcome a mechanical obstruction or a wrong upper limit. If the arms already stop short in normal use, the sensor will leave them short too.
Sources and standards consulted
- Tubular motor troubleshooting, limit-setting and remote pairing guides (manufacturer documentation)
- Lateral arm awning service manuals (pitch, arm and spring adjustment) (manufacturer documentation)
- Retractable screen manufacturer service and re-tensioning instructions (manufacturer documentation)
See how we research for our sourcing and verification process.