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How Not to Adjust a Commercial Door Closer

Picture of a commercial door closer

You’ve probably come across several articles explaining how to adjust a commercial door closer, but none if any really explain how not to adjust a commercial door closer. So with this in mind here are some tips and advice on the things you should look for and avoid when taking on this task.

As you may have already learned adjusting a commercial door closer is not too complicated, but it does require some time, effort and a few tools to ensure the job is done correctly.

Before adjusting your commercial door closer it’s important to understand that adjusting the closer incorrectly could potentially make the door harder to open, void the warranty and result in the closer being non-ADA compliant.

Get help adjusting or replacing your commercial door closer.

Getting Started

The first step to adjusting a commercial door closer is to locate the closer adjustment valves. This requires the use of a small ladder. Make sure the ladder is sturdy enough and tall enough for you to easily access the closer. Try to avoid working above your shoulder height as this can make the job of adjusting the valves more difficult.

Locating the Valves

The valves will either be located on the outside of the closer—making them easier to access—or inside the cover. If located on the inside, the cover will have to be removed in order to get to the valves, which makes the job of adjusting the closer a little more involved. If the valves are located on the inside and there are no visible fasteners holding the cover on, then it’s likely held in place by tension. Carefully remove the cover by pulling it away from the closer.

Once the cover is removed take note of any oil or fluid on the cover or on the inside of the door closer. If there’s oil present on the inside of the cover, or dripping from the closer body, it’s best to stop what you’re doing. Most likely there’s damage to the closer interior that will require replacing the door closer unit. If this is the case make sure to clean up any oil or fluid that may have leaked onto the floor.

Understanding the Adjustments

Commercial door closers use spring tension regulated by hydraulic fluid. When someone opens the door, hydraulic fluid passes from one reservoir to another. As the spring pushes the door closed again, the hydraulic fluid passes back to the previous reservoir through a series of valves that control the speed. So you might have to experiment with the valve adjustments before you find the right setting. Some closers will include a diagram or instructions on how to adjust the closer to increase or decrease the tension.

Making the Adjustments

After locating the hydraulic valves—some closers have three, others have two— it’s best to start by closing them all. The screws to adjust the speed of the closer will be labeled ‘L’ and ‘S’—latch and swing. The third adjustment is labeled ‘BC’—for backcheck. The backcheck is designed to keep the door from opening too far.

The settings can be adjusted using a screwdriver or Allen wrench to turn the valves clockwise until they stop. Once all three valves are closed, open the door to make sure it comes to a steady, hard stop. The door should start to slow down when it reaches about three quarters of the way closed. Make sure it doesn’t slam into the door frame or get caught by the wind. Turning the valves counterclockwise will allow the door to open wider.

As you’re checking the door closure, make sure no one is entering or exiting the doorway to avoid possible injury to you or them. When adjusting the valves start with small, incremental adjustments since it doesn’t take much to change the door closure speed. Turn the adjustment screw clockwise to slow the door closure speed, and counterclockwise to increase the closure speed.

Assessing the Adjustments

Once you’ve made a few adjustments, come down from the ladder and observe how the door opens and closes. Check the closing speed repeatedly to ensure it’s set correctly. Typically, a commercial door closer will close the door smoothly in just under 10 seconds. If air pressure is a factor—either positive or negative—adjusting the door to a slower closing speed often allows the air pressure to dissipate, which should solve the problem.

If the closer doesn’t close the door completely—or the door springs back slightly when you try to manually shut it—it’s possible the arm has been installed incorrectly. You can locate most installation instructions on the door closer manufacturer's web site to assess if installation was done correctly.

Occasionally a door needs to be repaired before it closes and locks properly. Unless you’re up for the task, and willing to invest the additional time and effort required, it’s time to call a professional. During your final check, if the closer arm makes any noise and/or rocks up and down when the door is in motion, try tightening the fasteners that hold the arm in place to see if this corrects the issue. If not, it might be time to replace the entire unit. If you need further help, guidance, or assistance installing your commercial door closer, call the experts at Glass Doctor for a free estimate.