How to Adjust Your Door Closer
Door closer adjustment is an art that requires knowledge, patience, and an ability to climb up and down a ladder several times, but with these attributes and the appropriate wrench, hex key, or screwdriver, you can do it yourself. This article is primarily about surface-mounted door closers, but the ideas here can be applied to other kinds of door closers as well.
Most of the adjustments are implemented by opening and closing hydraulic valves. When it comes to turning the screws that operate these valves, a little goes a long way. A turn of five degrees can significantly increase or decrease closing speed.
Do Not Completely Unscrew Hydraulic Screws
You will ruin the closer and void the warranty. Also, hydraulic fluid will leak out of the closer and make a mess.
How Door Closers Work
A door closer is a mechanical device designed to close a door slowly but firmly enough to latch. It accomplishes this by using spring tension modulated by hydraulic fluid. As the user 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.
The illustration above shows the effects of the common hydraulic adjustment controls available on most commercial grade door closers. Controls for swing speed and latching speed control how fast the door closes. Many closers also feature a hydraulic control for back check that controls the last few inches of the opening the door so as to prevent the door from being slammed into an adjacent wall.
- Swing speed adjustment controls how fast the door closes from fully open to within about five degrees of closed.
- Latching speed adjustment controls how fast the door closes for those last few inches.
- Back check adjustment controls the amount of resistance to opening the door past a selected point.
The illustration below shows the various hydraulic control valves. These might be located in many configurations, but you will usually see the back check control located somewhat away from the latch speed and swing speed controls.
There are also door closers equipped with an additonal valve for delayed action. Delayed action closers hold the door open for a longer period of time to allow persons with disabilities more time to get through the door.
Control Valve Placement
Notice the spring tension adjustment in the illustration above. Spring tension controls the "size" of a closer. The term is misleading, because it does not actually have anything to do with the physical dimensions of the closer. This type of size is determined by the width of a door. "Sized" closers—that is, closers that have a factory pre-determined spring tension for a particular door width—have no spring tension adjustment. Many door closers today are "non-sized," indicating that you can adjust the spring tension to fit the size of the door.
It is tempting to use the spring tension adjustment to solve problems—for example, in positive pressure situations where air flow is preventing the door from closing properly. However, the tighter you make the spring, the harder it will be to open the door. It is possible to tighten the spring tension so that some people will not be able to open the door.
Making an Adjustment
To adjust the door closer:
- Bring a step ladder tall enough so that you can easily reach the door closer from the second- or third-highest step.
- Climb the ladder and examine the closer. If you can't see adjustment screws, chances are the closer has a cover. Usually the cover is plastic, but it could also be metal. If you see no fasteners holding the cover on, that means the cover is held on by tension. Pull it off. If you do see fasteners, usually you can loosen, but not remove, the fasteners and the cover will slide off.
- If you find that there is oil in the cover or oil on or leaking from the closer body, stop right now. You need a new door closer. If, however, it is not leaking, you can proceed.
- Now that you have the cover off, you should be able to see the adjustment screws. If you are lucky, they will be marked on the closer body as to what they are or there will be a diagram inside the cover. If not, you may have to experiment a little to see which is which.
- Remember, when it comes to turning door closer adjustment screws, a little goes a long way. Start with no more than 1/8 of a turn. Turn the adjustment screw clockwise to slow the door closer down, counter-clockwise to speed it up, then get down off the ladder and observe the effect.
- Open the door and watch it close. If it closes right the first time, check it 10 more times. If it closes correctly every time, you're done. If not, go back up the ladder and make another adjustment, until the closer is doing what you want it to do.
- When it closes the way you want 10 times in a row, it will probably continue to do so.
- Ideally a non-delayed action door closer will close and latch the door in seven to eight seconds.
Problems and Trouble Shooting
- If you expect a door closer to consistently close the door, the door must be able to close properly. If there is a hinge problem, a warped door, or the door must swing uphill to close, a door closer will only go so far to solve the problem. Sometimes a door must be repaired before it will close and lock automatically with a door closer.
- In vestibule conditions there is an exterior door, a small space, and then an interior door. The trapped air between the inside and outside door can be a factor in door closing. You may have to adjust both closers to get both to work correctly. Wherever air pressure is a factor, including negative or positive pressure situations, I have have been able to get door closers to close and latch the door consistantly by adjusting them to a slow swing-speed and a somewhat fast latch-speed. The slow swing-speed seems to give the air a chance to get out of the way and the fast latch speed gives it a very slight slam at the end to make sure it latches.
- If the closer stops closing the door before it's closed all the way, or actually spings back when you try to manually shut the door, the arm is probably installed on the shaft incorrectly. Download the instructions from the door closer manufacturer's web site and see if it is installed correctly.
- If the arm makes noise and bounces up and down while the door is in motion, tighten the fasteners that hold the arm to the closer, to the header, and at the knuckle that holds the two parts of the arm together.
When it's time to replace your door closer:
- If oil is leaking from your door closer, throw it away and buy a new one.
- If your door closer is slamming the door and cannot be adjusted to do otherwise, either the fluid has leaked out or the valve seals are worn out. Either way, your best option is to replace it.
- If the door closer has no spring tension and the spring tension adustment turns round and round with no effect, the spring is broken the door closer must be replaced.
Questions & Answers
My Dorma RTS85 door closer is slamming. I have tried tightening both of the screws as per the manual, but it is still slamming. Would you have any tips on this before I consign it to the bin and order a new one? There are no leaks anywhere, but this has been slamming since long before I started, and this is on an old warehouse door.Helpful 10
- Helpful 7
How can we make our LCN door closer open farther?
The degree of opening is adjustable - to an extent. If your closer is mounted on the door on the push or pull side, you can download the install instructions from Allegion. They will show you how to adjust the degree of opening. It may mean changing the location of the closer body and arm shoe.
If your closer is mounted on the header above the door, then you may have to purchase a longer arm. With top jam mounting, the degree of opening is most affected by the depth of the "reveal" - that is, the distance between the inside surface of the door frame and the surface of the door.
© 2008 Tom Rubenoff