How to Adjust a Door Closer | Locksmith Explains

Last Updated on October 11, 2023

Adjusting a Surface Mount Door Closer

A hydraulic door closer is a mechanical device which automatically closes a door using springs and a system of chambers filled with hydraulic fluid.

You do not need to hire a locksmith to adjust a door closer if the door closer is still in good condition.

To adjust a door closer, use either a screwdriver or hex key. Make minor adjustments to the swing speed (S), latch speed (L), back check (B), or delayed action by turning the screw less than 1/8 turn. Counterclockwise increases speed/force, clockwise decreases it. After turning a screw, test the door, and repeat as needed.

A properly adjusted hydraulic closer helps ensure the closer will last longer and that the door itself lasts longer (an improperly installed or malfunctioning closer will negatively impact the door and/or its framing).

CAUTION: Improperly adjusting a hydraulic door closer can be dangerous and cause serious harm. We have seen door closer pieces stuck in walls. Attempt all adjustments at your own risk. Hire a local commercial locksmith if you have any concerns.

4 Steps to Adjust a Door Closure

1: Remove Cover to Access the Adjustment Screws

Adjust Door Closer
Surface Mount Door Closer
Concealed Door Closer

The most common door closers are Surface Mounted. To access their hydraulic valve adjustment screws, you need to remove the door closer cover.

Some covers are held on by tension alone. Some may be held on by a couple of screws located on the sides of the cover. The screws will be easily visible.

The second type of closer is a concealed door closer. The body of these closers are hidden in a ‘pocket’ at the top of the door frame (or within the door itself).

The adjustment screws for the concealed door closers are accessed via holes present in the frame.

2. Inspect the Closer to See if it Must be Replaced

Door Closer Leaking Oil

If your door closer is shot, adjusting it will not solve your problem.

To determine if you need to replace your door closer, look for any visible oily leaks or oil stains around where the closer is housed. If you see oil, stop. There’s no need to go further. A leaking door closer needs to be replaced.

To learn why this oil is so important, see our article on How Door Closers Work.

If you are skilled with tools, you can likely replace a leaking surface mount door closer on your own. You can find many commercial door closers on Amazon for good prices.

Concealed door closers should only be replaced by a skilled, licensed, commercial locksmith.

3. Make Small 1/8 Turn Adjustments to the Screws

Door Closer Screw Labels
The Most Common Door Closer Adjustments

When making adjustments to the screws, makes very slight turns, 1/8 turn at a time, to the adjustment screw. Small turns make big differences in the door closer operation. Counterclockwise turns increase speed/force. Clockwise turns decrease it.

The two main door closing issues are either the door is slamming shut or the door is not shutting fully.

These issues can be resolved with the adjustment of two valves, the sweep speed valve (labeled S) and the latch speed valve (labeled L).

Swing speed (or sweep speed) is how long it takes the door to swing fully closed. You want the door to close in 7-9 seconds.

Latch speed controls the force the door closes at in the last 4-5 inches just before shutting. If the door is not fully closing (staying open a inch or so), adjust the latch speed.

Back Check (Labeled “B” or “BC”) controls how the door’s resistance responds when opening the door past a certain point. If a customer says the door is hard to open, or when the wind catches the door it flies open, adjust the back check.

Jump to a detailed explanation of available hydraulic door closer adjustments below.

The process for adjusting any of the valves is the same for each.

One VERY important thing to note before making any adjustments. Do not make large turns that might cause the valve screws to come out. DO NOT, UNDER ANY CIRCUMSTANCES, COMPLETELY UNSCREW A VALVE SCREW!


4. Test the Door & Repeat as Necessary to Achieve Desired Door Closer Settings

After each slight adjustment, test the operation of the door to see if it is now at it’s desired rate. If it is not, repeat with another slight adjustment and test again.

Once you have your door closing properly once, repeat the test multiple times, even 10 times, to see that it closes properly each time.

If, after a couple of “adjust door closer” attempts, it still won’t work consistently, then there may be other issues with the closer that cannot be addressed with adjustments. Typically, it will need to be replaced, as while repair MAY be possible, it would be labor intensive, making replacement a more economical fix.

See our detailed article, “When is it Time to Replace a Door Closer” link

Commercial Door Closer Adjustments

To learn why these adjustments work, see our article on How Do Door Closers Work.

Adjusting the Door Closer Speed

Door Closer Adjustment Diagram
Door Closer Adjustments Diagram

The S on a door closer means “swing speed.” It is the time measured from the door held open at 90 degrees and released, until the time that the door reaches 12 degrees from being fully closed. That time must be greater than 5 seconds.

The door’s closing swing speed (or sweep speed) is adjusted by turning the screw that is labeled with an “S.” In European models, the sweep speed valve will be labeled ‘1’.

Ideally, an open door should close in 7-9 seconds. Be sure to check with your local governing bodies regarding ordinance codes to ensure that you are making adjustments within compliance regulations in your area.

Adjusting the Door’s Latching Force

The L on a door closer means Latching speed. Latching speed controls the last few inches of the door closing. You can increase or reduce the force to ensure the door latches properly but does not slam. Customers often refer to this as the door closer pressure since it is the adjustment that makes sure the door holds shut.

A door’s latching speed is controlled by turning the screw labeled “L”. In European models, the latch valve will be labeled ‘2’.

The latching valve only affects the door when it is in the last moments of closing (10-20 degrees typically). Vestibule entryways, windy areas, and air pressure differences cause by the HVAC between inside and outside are known reasons you may need to adjust the latching force.

Adjusting How Easily the Door Opens

Back Check – some hydraulic door closer models allow adjusting the back-check.

A “B” or “BC” on a door closers stands for Back Check and means how the door’s resistance responds when opening the door past a certain point.

Sometimes we hear customers say that the door is hard to open or that they want us to adjust the tension on the door closer, in these cases they are often referring to back check.

Adjusting the Door Closer Delay

Delayed Action – You may also be able to adjust the delayed action of the door. When the door is open the delayed action is a delay time that is set to hold the door open for a bit (up to about 30 seconds) before the door proceeds to close.

Video: Adjusting Door Closer Speed and Latch

Watch ACME Locksmith demonstrates how to adjust a door closer.

Answers to Common Questions

Why Won’t My Commercial Door Close all the Way?

AC units can cause a difference in air pressure inside the building from that outside of the building. When the AC is on, the inside pressure is stronger and the air wants to escape the building. This air pressure pushes against glass aluminum doors, and can be strong enough to keep the door slightly open. To fix this, increase the latching speed force of the door closure.

Which Way do You Adjust a Door Closure?

Counterclockwise door closer screw adjustments will increase the speed or force of the adjustment. Clockwise turns will decrease the speed or force.

Why is There Oil on My Door Closure?

If you see oil on your door closer or on the door / framing around your door closure, the door closer has failed and it’s time to replace the door closer.


Adjusting a door closer for speed and latching is a project that most business owners of maintenance staff can easily handle. However, if you see any oil stains in the vicinity of the door closer, you need to replace it right away to avoid liability. Surface mount door closer replacement is a project you may be able to handle based on your skill level, but concealed door closers should only be replace by a professional, commercial locksmith.

Disclosure: As an Amazon / Google / Home Depot / eBay Associate I may earn from qualifying purchases.

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