If you manage a facility or a storefront, automatic door troubleshooting is one of those tasks you don’t think about—until an entryway sticks open during a storm, closes too quickly near a customer, or simply refuses to budge at 8:59 a.m. While power failures, worn rollers, or misadjusted controllers can all cause headaches, one category deserves special attention: safety sensors. These devices tell a door when to open, when to slow down, and—most importantly—when not to move because a person, cart, stroller, or service animal is in the way.
Below, we’ll explain what safety sensors are, why they’re essential, how to recognize early warning signs, and practical steps you can take to test and maintain them for compliance and peace of mind.
Purpose of Door Safety Sensors
Automatic doors create fast, convenient access—but speed without situational awareness is dangerous. Safety sensors provide that awareness, continually watching the approach, threshold, and swing/slide path to prevent unwanted contact and entrapment. In short, sensors:
- Detect approaching traffic to activate a door at the right time.
- Create a presence zone to keep a door open while people or objects are in the path.
- Interrupt or reverse motion when someone enters the danger area mid-cycle.
- Adapt to changing environments—light, floor reflectivity, and movement—to stay reliable throughout the day.
When a sensor is clean, aligned, and correctly configured, customers enjoy seamless access, and you reduce liability exposure. When a sensor fails or drifts out of adjustment, the door may open late, “ghost” open, or close when it shouldn’t—each a safety and compliance risk.
ANSI Safety Standards
For commercial pedestrian doors in the United States, ANSI/BHMA standards define how doors should behave and how sensors contribute to a safe system. Two standards commonly referenced by facility managers and architects are:
- ANSI/BHMA A156.10 – Power-Operated Pedestrian Doors. This covers full-energy sliding, swinging, and folding doors typically found at hospitals, airports, supermarkets, and campuses. It specifies activation and safety requirements, including the number and placement of sensors, detection zones, and performance criteria.
- ANSI/BHMA A156.19 – Low-Energy and Power-Assist Doors. This applies to low-energy swing operators—often used to meet accessibility goals—where doors move more slowly and with lower force but still require appropriate safety methods.
These standards work hand-in-hand with AAADM (American Association of Automatic Door Manufacturers) guidelines, which recommend regular inspections and daily safety checks by the door owner. While technicians perform annual or semi-annual inspections, staff should be trained to perform quick daily tests (more on that below) to catch issues before they become incidents.
Common Types of Safety Sensors
Understanding sensor types helps you diagnose problems efficiently and speak the same language as your service provider. Here are the most common categories you’ll encounter on sliding, swinging, and revolving doors.
1) Approach (Activation) Sensors
What they do: Detect a person or cart approaching an entryway and signal the controller to open the door early enough to maintain a comfortable flow.
Where they are: Mounted above the door or on the header, typically aiming outward.
How they work:
- Microwave radar sensors detect motion using Doppler technology; great for speed and range, less sensitive to stationary objects.
- Active infrared (AIR) approach sensors emit and receive IR light, detecting motion and sometimes presence in a defined field.
- Dual-technology units combine radar for activation with infrared for near-field presence, improving immunity to false triggers.
Common issues:
- Late opening (field set too small or angled too low).
- False triggers from moving foliage, busy streets, or reflective surfaces.
- Seasonal drift due to temperature, mounting vibration, or controller changes.
2) Presence (Safety) Sensors
What they do: Create a safety zone in the door’s swing or slide path to keep it open while people or objects remain in harm’s way and to stop/reverse motion if someone enters the zone mid-cycle.
Where they are: On the header aiming downward, on the door leaf for swing paths, or built into the operator assembly for sliding doors.
How they work:
- Active infrared presence sensors project a matrix of beams or a “curtain” that recognizes stationary objects—strollers, mobility aids, luggage—as well as people who pause.
- More advanced units track detection density and compensate for floor reflectivity so dark rugs or shiny terrazzo don’t cause blind spots.
Common issues:
- Dead zones from dirt on the lens, mis-aimed brackets, or warped covers.
- Over-sensitivity keeps doors open too long, hurting energy performance.
- Under-sensitivity risks contact.
3) Threshold (Photoelectric) Beams
What they do: Provide a simple, reliable tripwire across the threshold to prevent a sliding door from closing on a person who steps in at the last second or a swing door from moving when the beam is blocked.
Where they are: Emitter and receiver on opposite jambs or within the header assembly.
Common issues:
- Misalignment due to bumped posts or settling floors.
- Intermittent breaks from carts repeatedly striking housings.
- Sunlight interference in glass vestibules if lenses are not properly shielded.
4) Safety Mats (Less Common in New Installs)
What they do: Pressure-sensitive mats detect weight in the swing path, stopping motion or holding a door open.
Where they are: Floor area adjacent to the door.
Common issues:
- Edge damage causing unreliable detection.
- Moisture intrusion leading to nuisance alarms or dead zones.
5) Touchless (Non-Contact) Actuators
What they do: Facilitate non-contact door openings via a wave-to-open gesture or proximity read—popularized during COVID-19 to reduce touchpoints.
Where they are: Wall-mounted near the approach zone or integrated into access control.
Common issues:
- Gesture distance set too short or too long.
- Ambient light false triggers if units aren’t filtered or mounted correctly.
- User confusion without clear signage or iconography.
Maintaining and Testing Sensors
A well-designed automatic door system is only as safe as its ongoing maintenance. Routine cleaning, functional checks, and documented tests are the backbone of compliance and longevity.
Daily Safety Check (2–3 Minutes)
Train opening staff to run a short checklist before business hours:
- Visual inspection – Confirm housings are secure, lenses are clean, and nothing obstructs the approach or swing path.
- Approach test – Walk toward the door at a normal pace from several angles. The door should open early enough for a comfortable pass without slowing or stopping.
- Presence hold-open – Stand motionless in the path; ensure the door remains open. Step out; the door should close after its programmed hold-open time.
- Interruption test – As the door begins to close, step into the safety zone; it should stop and reopen immediately.
- Threshold beam test – Move a flat object (or your leg) through the beam; the door should not close while the beam is interrupted.
- Signage and decals – Verify mandated decals (arrows, “Automatic Door,” “Activate to Open”) are present and readable.
Log the results in a daily inspection sheet. Consistent documentation demonstrates diligence and helps technicians isolate intermittent problems.
Weekly/Monthly Preventive Tasks
- Clean lenses and covers using a microfiber cloth and a mild, non-ammonia cleaner. Harsh chemicals can haze plastics and reduce sensor performance.
- Check alignment of photo beams with a simple alignment card or by observing the device indicator LEDs.
- Verify detection fields by using a standard test target (e.g., a small box or AAADM test object) to confirm the full footprint of the presence zone.
- Tighten hardware on sensor brackets, headers, and jambs to prevent drift from vibration.
- Review controller settings (DIP switches or software parameters) for hold-open time, reactivation behavior, and sensor priority.
- Observe traffic patterns—if customers frequently slow or pause near the doorway, your presence field may need to extend farther or be differently shaped to match reality.
Quarterly/Biannual Professional Inspection
Even with vigilant in-house checks, plan on regularly scheduled qualified service visits. A certified technician will:
- Perform calibrated field measurement of detection zones against the door’s speed and weight.
- Test redundant safety functions—for example, ensuring the controller reacts properly if a primary presence sensor fails.
- Validate fail-safe behavior (door opens safely or stops) during simulated power loss.
- Review access control integration (badges, intercoms, fire alarm tie-ins) so safety overrides always take precedence.
- Update firmware or apply manufacturer bulletins and energy-compliance optimizations.
Sensor Failure Warning Signs
Catch these early indicators to prevent downtime and reduce risk:
- Late or abrupt opening. Approach sensors may be under-aimed or fields too small.
- Door “hunting” or ghost openings. Overly sensitive radar picking up distant movement or reflections.
- Door closes with someone nearby. Presence field has blind spots or insufficient density; a lens may be dirty or bracket knocked out of position.
- Intermittent stop/reverse. Misaligned threshold beam or loose wiring.
- Excessive hold-open time. Field too large or excessive “presence” sensitivity, often killing vestibule efficiency and HVAC load.
- Frequent alarms or blinking indicator LEDs. Some sensors display error codes for internal faults, power issues, or blocked optics.
- Customer complaints. Listen carefully: “It closed too fast,” “I had to wave three times,” or “It didn’t see my stroller” are valuable diagnostics.
When these symptoms appear, start with cleaning lenses and checking alignment. If the behavior persists, escalate to adjustments or a professional service call.
How to Diagnose Like a Pro (Safely)
- Isolate the variable. Disable or cover one sensor at a time (following manufacturer safety procedures) to see which input changes behavior.
- Use onboard indicators. Most sensors and controllers include status LEDs that show when a field is active, blocked, or faulted.
- Check power and wiring. Loose connectors, pinched cables in the header, or shared power supplies can create unpredictable behavior.
- Confirm controller logic. Many operators allow you to prioritize inputs (e.g., presence overrides activation); make sure logic has not been inadvertently changed.
- Document settings before adjustments. If your change doesn’t help, revert safely.
- Lockout/Tagout when necessary. If you need hands inside the header or closer access to the operator, cut power and apply LOTO to avoid unexpected motion.
Important: Never compromise safety to get the door moving. If disabling a sensor would allow unsafe operation—even temporarily—take the unit out of service and call a qualified technician.
When to Replace Safety Sensors
Sensors are durable, but they do not last forever. Consider replacement when:
- Age and obsolescence. Electronics drift over time; if a sensor is 8–12 years old or manufacturer support has ended, replacement can boost reliability and compliance.
- Environmental mismatch. If you’ve changed flooring (high-gloss tile) or lighting (sunny vestibule), older sensors may struggle. Newer models offer better immunity and adaptive algorithms.
- Repeated nuisance faults. If cleaning, alignment, and configuration tweaks don’t resolve intermittent errors, internal components may be failing.
- Upgrading to touchless access. Post-COVID, many facilities replaced push plates with wave-to-open or integrated sensors to reduce touchpoints while maintaining accessibility.
- Energy and performance goals. Modern sensors can reduce false holds, improving vestibule performance and meeting automated door energy compliance targets.
When evaluating replacement, look for dual-technology designs (radar + AIR), dense presence curtains, robust sunlight immunity, and clear diagnostics. For swinging doors, consider sensors that protect both the opening and closing arcs, especially in corridors with cross-traffic. For sliding doors, ensure robust threshold protection and side-screening to prevent entry from being misread as exit.
Maintaining and Testing Sensors
Proactive care is the difference between “We got lucky again today” and “Our doors are consistently safe and dependable.” Here’s a deeper program you can adopt or tailor with your provider.
Build a Door-Specific Checklist
Each door has unique geometry, traffic patterns, and surrounding hazards. Create a one-page sheet that lists:
- Sensor types and brands installed, with serial numbers and firmware where applicable.
- Field diagrams showing the intended detection zones and any physical constraints (planters, displays, vestibule doors).
- Test points and expected outcomes for daily and weekly checks.
- Service history with dates, technician notes, and parts replaced.
Train Multiple Staff Members
Cross-train so coverage doesn’t lapse during vacations or turnover. Include quick “what to do if” scenarios: e.g., if the door won’t close because a beam is blocked, check for carts or signage moved into the path; if the door “freezes,” call the designated service number and post a “Use Other Door” sign.
Keep the Area Clear
Clutter is the silent killer of sensor performance. Seasonal decorations, point-of-purchase displays, or temporary banners often creep into detection zones. Maintain clear setbacks around the approach and swing/slide paths and revisit after merchandising changes.
Document, Document, Document
It’s not just about compliance—it’s about continuous improvement. A simple logbook or digital form helps you spot trends like “false trips at dusk” (perhaps sunlight sweep across the vestibule) or “late opening on rainy days” (dark umbrellas reducing floor reflectivity for certain presence sensors).
Practical Troubleshooting Scenarios (With Likely Causes)
- Door opens fine in the morning, false-triggers all afternoon.
Suspects: Sunlight angle hitting lenses, reflections from parked cars, nearby HVAC curtain.
Action: Add lens hoods, adjust sensor angle, refine radar “reject” area, or add auxiliary shielding. - Door sticks open whenever a cart display is near the entry.
Suspects: Presence field overlapping the display.
Action: Re-aim presence curtain; reduce field size; relocate the display outside the zone. - Door closes on slow-moving individuals with walkers.
Suspects: Presence density too low; zone too small.
Action: Increase beam density, extend field farther into the path, verify closing speed/force per standard. - Door won’t close at all; indicator LED on beam is off.
Suspects: Broken wire, power issue, or beam misalignment.
Action: Check power to the receiver, reseat connectors, realign the beam, replace if non-responsive. - Wave-to-open requires multiple attempts.
Suspects: Gesture distance set too short; IR noise; actuator placed too high/low.
Action: Adjust activation range, verify clear sightline, add signage with gesture icon.
Compliance, Risk Management, and Customer Experience
Great sensor performance achieves three outcomes:
- Compliance with standards (ANSI/BHMA and AAADM guidance), documented by daily checks and scheduled professional inspections.
- Lower risk for your business—fewer near-misses, reduced incident probability, and stronger defensibility if something goes wrong.
- Better experience—doors open predictably, move smoothly, and minimize contact for hygienic operation, which customers notice and appreciate.
As you refine your program, align sensor tuning with energy goals (limiting unnecessary hold-open time) and accessibility (accommodating varied walking speeds, mobility devices, and visual cues). Modern systems make it possible to be both safe and efficient.
When to Call a Professional
There’s plenty you can do in-house, but call a qualified provider if you encounter:
- Persistent faults after cleaning and alignment checks.
- Any contact or near-miss incident—have the system professionally evaluated before returning to service.
- Controller alarms or error codes you can’t interpret.
- Hardware damage to sensors, cables, or mounting points.
- Integration changes (adding access control, touchless actuators, or vestibule sequencing).
Professionals bring calibrated tools, manufacturer software, and experience across thousands of doorways—turning guesswork into data-driven adjustments.
Call the Experts: Door Automation Corporation
If you’d rather spend your time serving customers than chasing sensor quirks, Door Automation Corporation is ready to help. We provide solutions for convenient access to commercial spaces with automatic and manual swing, slide, and revolving doors. Our reliable professionals work with industry-leading products to deliver functional, dependable, and secure entryways tailored to your building’s traffic patterns, aesthetics, and compliance requirements.
Non-contact door openings became the norm during COVID-19, and many organizations continue to prefer them for hygiene and accessibility. Door Automation Corp can retrofit touchless, non-contact door operation—including wave-to-open actuators and advanced presence sensing—so your entrances feel modern, safe, and welcoming. Planning a new build or a major renovation? We also provide new automatic doors that meet standard automated door energy compliance, reducing energy loss while maintaining a smooth flow of people.
We don’t just install hardware—we collaborate. Our team works closely as design consultants with many of the top architectural firms in New York City, helping translate design intent into code-compliant, beautifully executed entries. Whether you manage a single storefront or a multi-building campus, our skilled team is here whenever you need us for inspections, upgrades, and 24/7 service.
Ready to make automatic door troubleshooting a non-issue? Contact us today to schedule a safety and performance assessment or to discuss touchless upgrades and energy-compliant solutions for your entrances.
