Skip to main content
Welcome to the cutting edge of safety science—Learn more about our rebrand.
  • Feature Story

Convenience and Safety Working Together: Unattended Operation for Residential Garage Door Operators

Many garage door openers now have smartphone capabilities. Learn about how UL 325 can keep your residential garage opener safe in the summer months.

Garage Doors

June 19, 2019

Written by: Steve Kuscsik, principal engineer – motor operated and radiant heating products

An automatic garage door is a common convenience in many households. It allows easy access to your garage — and even your home -  simply by the touch of a button on your key chain remote, your car visor, a keypad mounted outside the garage, or on a wall inside your garage.

With the large increase in smartphone use today, and the number of apps and connected devices continuing to increase, the garage door operator has not been left out.  In fact, some view the garage door ecosystem as leading in terms of automation, convenience, security, and connectedness.  Many garage door operators today have features that allow you to view the status of your garage door and open or close the door from your phone. This can offer additional convenience when a package is being delivered, when you need to let someone into the garage, or if the garage was mistakenly left open.

As with many conveniences brought about by technology, the safety implications also need to be considered. An automatically operated garage door can be a large and heavy moving object, with people moving about in the driveway and inside the garage.  The risk of injury or entrapment underneath a garage door is real. Thankfully, the garage door and operator industry, the Consumer Product Safety Commission (CPSC), and product certification agencies, such as UL, have worked hard to help ensure that these products meet a common level of safety. The main safety Standard in the U.S. and Canada that addresses garage door operators is UL 325, the Standard for Door, Drapery, Gate, Louver, and Window Operators and Systems.

When a smartphone is used to close your garage door, the industry refers to this as “unattended operation.” It is unattended in the sense that the person “operating” the door may not be in the immediate vicinity of the moving door. When a person operating the door is in the immediate area, they play a role in observing the door area, and deciding if it is safe to close the door.  Unattended operation via mobile phone allows operation of the door from almost anywhere in the world that has a cellular or internet connection.  The person pressing the “button” on the phone could be anywhere, from at the office to across the continent, and is not likely in the immediate area to observe the door and decide if it’s safe to close or open the door.

This added convenience is embraced by industry and users alike. However, for this feature to work on residential garage door operators, it is required to be coupled with several additional safety features. These additional features are intended to provide an alert before the door closes, limit the number of attempts to close the door, and to work only on compatible door systems that have more modern safety features, such as photo eyes.

Several of the specific requirements are:

Before the door can close, a visual alert in the garage must flash for at least 5 seconds.  There are requirements for the visibility, flash rate, etc.


image 6

Before the door can close, an audible alert in the garage must sound for at least 5 seconds.  There are requirements for the sound level and frequency.


image 5

If the door does not fully close after two attempts from the unattended signal (i.e. from smartphone) due to an obstruction (activation of a photo eye, edge sensor or inherent reversal system), the door operator system must lock out or ignore additional attempts to close from the unattended system. This is to prevent someone from a remote location repeatedly starting the door in the downward direction, when it is unsafe to do so. The ability to close the door via smartphone can be reset when someone in the area of the door presses a “local” control to move the door.

image 4

Unattended operation is only permitted for vertically moving sectional garage doors (most common type) and horizontally sliding doors.  It is NOT permitted for one-piece overhead door, and swing type garage doors.

Image 3


An accessory device that is sold as an “add on” to an existing garage door operator, must explain in the instructions which door operators it is compatible with. 

image 2


Some accessories are required to have the visible and audible alerts built-in as part of the accessory that you buy and install.

image 1



Meeting these requirements is not just a good idea or a best practice. In fact, it is a mandatory part of the industry Standard UL 325 and is also established as part of U.S. Federal law according to the U.S. Consumer Product Commission (CSPC) code 16 CFR Part 1211. 

Unattended operation is not limited to activation via smartphone. Many garage door operators also have timers that allow the user to set a time period whereby a door that remains open for a certain period of time will close automatically, without a user pressing the wall control or remote control. Since a person may not be in the immediate area when the door closes, this feature is considered a version of unattended operation. The operator system must have the same additional safety features as described above.

So, should you check before buying a device that claims to allow a smartphone to close your garage door? Absolutely! As the saying goes, “Not all devices are created equal.” Some garage door operators have added these features built in to the main operator, so a separate device is not needed. There are also several accessory/add-on devices sold on the market that do in fact comply with all the proper safety requirements. However, there continues to be a number of accessory-type devices on the market that do not meet the essential safety requirements – the requirements that are industry standard and required by law. Many of these are sold online, some by well-known retailers.

How do you know if a device that provides smartphone control for your garage door has all the necessary safety features? This can most readily be verified by looking for a UL Mark on the garage door operator, or on the accessory if it is purchased separately. Although federal law provides alternative means of providing evidence of compliance, a UL certification Mark on the product is the most common way to tell.  Manufacturers, door operator dealers and installers/service companies should ensure that the products they carry and install are properly certified for compliance with UL 325. Retailers who offer these products for sale should be sure that the devices they sell are in fact fully complaint with the regulations. If not, the reputation of the company and the safety of the users could be at stake. In short, look for evidence that the garage door operator or the accessory that you are buying clearly shows that it meets the UL 325 safety requirements.

With the summer months just around the corner, the garage door is likely to be used more, such as when doing yard work, accessing bicycles, and other warm-weather activities. Considering the garage door is often the most-used gateway to and from the home, it is important to bring awareness to the potential dangers garage doors and automatic opener systems can cause if they’re not kept in proper working condition. June has been designated as National Garage Door Safety Month by the International Door Association (IDA) and Door & Access Systems Manufacturers Association (DASMA).  In addition to reading and following the instruction manuals that come with the garage door operator or accessory, a very useful list of additional tips to keep you, your family and your property safe this summer can be found at the IDA website:  and at the DASMA website:

After all, when it comes to your garage door, added convenience should not come at the sacrifice of safety. With properly compliant devices for unattended operation of the garage door, it doesn’t have to!

Information about the CPSC requirements for residential garage door operators can be found at and via this direct link to 16CFR Part 1211: Additional information about UL can be found at and via this direct link to UL 325 Standard: