3 basic zones associated with door closers you need to know

Description: For adjustment and repair of door closers, people often use in offices and commercial buildings. There are three basic zones associated with door closers you need to know. Read on this article for more information.

Three basic operation of door closers

Door closers close a door automatically at an adjustable speed. People usually mount the door closer at the top of door or above it on the jamb. There are internal models installed hidden inside the door frame for a cleaner look. The internal spring applies force to the arm to close the door. Hydraulic fluid will flow through pathways inside the closer. The resistance/restriction to fluid flow helps determine the door closing speed.

The spring strength and adjustment varies by model. Accordingly, heavier doors require stronger closers. Door closers match to their application. They based on door size, weight and the corresponding strength needed to close them properly.

Adjustable spring tension will allow models so equipped to work well for doors of sizes within their range of adjustment. The operation of a door consists of 3 basic zones: Adjust, troubleshoot and repair.

Picture 1: Understanding three zones of door closers is very necessary

Adjustment of door closers

These instructions are for a door closer to operate properly. If the door closer does not operate properly, you can read Troubleshooting section before adjusting. The adjustment screws require a hex wrench as always. Accordingly, the closer may have a cover. You must remove it before being able to access the adjustment screws.

You should not unscrew the adjustment screws. That’s because they will fall out and oil will spill. In general, turning a screw clockwise will increase resistance or slow the door. The counter-clockwise will do the opposite. The adjustments can be sensitive. So you should start with a 1/4 turn.

Adjustment of door closers: Consider these things below

  • A slow-moderate sweep and a slow, quiet latch. In some cases, environmental factors will not allow an ideal adjustment.

  • The door will not latch when adjusted to a slow latch speed. Your latch bolt may not function smoothly. Or you install it incorrectly.

  • Your door requires a higher closing force. Then, adjust PA (power assist) or spring tension if available.

  • There are variables to take into account

  • You need to adjust door to close properly across all conditions. They include wind, snow, ice, etc.

  • Some ventilation systems cause the door to blow open or pull shut. Therefore, you need to adjust the latch speed to a little faster. This is to overcome a positive pressure or slower to handle a negative pressure.

  • Adjusting your arm length to lengthen or shorten the latch zone.

  • The arm length adjustment can cause your max open angle or backcheck zone to engage earlier.

Picture 2: Adjusting door closers is quite complex step

Troubleshooting of door closers

Low oil can cause most problems. This oil level can look like:

  • The door swings too fast to a point mid-swing. At which it closes at a normal slow pace.

  • The door swings closed without any resistance, slamming against door jamb/frame.

  • Changing adjustment screws is not effective.

  • The oil puddle underneath door closer unit

  • The oil drops on bottom of arm

Oil loss is usually because of:

  • The adjustment screw being removed

  • Leaking adjustment screw seals

  • Leaking arm shaft seals

Repair of door closers

Smaller door closers are relatively inexpensive, figure in your time. Therefore, you can consider replacing them. For heavy duty door closers, they can be expensive and hard to find replacements for. You should check to see that door closers are not under warranty. With our following instructions, you may not need any warranty.

Picture 3: It is useful to learn how to refill oil for door closers

Repair seals / Refill Oil:

You can successfully refill door closers using 3-in-1 household oil.

  • You should wear safety glasses

  • Must note the leaks and their apparent origin

  • It’s good to remove door closer unit from the door or top jamb

  • You should move unit to a suitable workspace. It can be oil will drain and sometimes squirt from unit during refill process.

  • You can remove adjustment screws or other hardware. It is to gain access to seals.

  • You can remove seals or take the screw/shaft with the o-ring on it to the hardware store.

  • Next, match the o-ring with a new one at the hardware store.

  • Re-insert BC adjustment screw, tilt and hold closer. It's on its end, with the S and L adjustment screw ports facing upward

  • You will fill ports with oil, then slowly move the closer arm to distribute oil internally. If you move too fast, the oil will squirt out.

  • Last, fill to top and re-insert adjustment screws with fresh seals.


You want to save yourself some time adjusting. Then, you can count the number of turns while removing the adjustment screws. When reassembling, you can turn them in the same number of times. This is to get close to your original settings.

At HeleH store, we have a variety of door closers for you to choose with detailed instructions. You can fix, repair basic fauls by yourself. To get more, contact us at: http://heleh.it/