Door closers: choosing the force and adjusting step by step

A door closer is an unassuming piece of door hardware that has a real effect on comfort, safety and the life of the leaf. It closes the door automatically and under control after every opening, so the entrance always stays shut. In this guide we explain how a door closer works, how to match its force to a particular door, and how to adjust the closing step by step so that it is quiet, smooth and sure.

What a door closer is and how it works

A door closer is a mechanism usually mounted at the top of the door, on the leaf and the frame, linked by an arm. Inside it are a spring and a hydraulic system filled with oil. As the door opens the spring stores energy; when the leaf is released it gives that energy back, closing the door smoothly. The hydraulics control the speed, so the door does not slam but shuts under control. A good-quality closer works reliably for many years and thousands of cycles.

How to choose the closing force

The most important figure is the closing force, normally given in classes from 1 to 7 under EN 1154. The wider and heavier the leaf, the more force is needed. Broadly:

• classes 2 to 3 suit lighter internal doors up to about 850 mm wide,
• classes 3 to 4 suit typical entrance doors up to about 950 mm,
• classes 4 to 6 suit wide and heavy doors and places with draughts and pressure differences.

Too weak a closer will not shut a heavy door; too strong a one makes it hard to open, which is a nuisance for children and older people. Many models have force adjustable within a range, which helps with matching. It is also worth checking whether the model is meant for internal fitting only or for external too, where it has to cope with changing temperatures.

Adjusting a door closer step by step

Most closers have two or three adjustment valves, usually on the side or the end of the body. Adjustment is made with a small screwdriver, turning the valves very gently, normally no more than one turn.

1. Closing speed: sets the pace of the leaf over the main part of its travel. Turning one way slows it, the other speeds it up.
2. Latching action: governs the last stretch just before closing, so the leaf reaches the frame firmly and engages the latch.
3. Delayed closing, where fitted: holds the door open longer, which helps when passing through with luggage or a trolley.

Adjust one valve at a time and try the door after every change. A well-adjusted closer shuts the door smoothly, without slamming, while still engaging the latch reliably.

Where door closers earn their keep

Door closers are used on the entrance doors of houses and flats, in offices, shops, schools, clinics and public buildings with heavy traffic. Wherever a door should always return to the closed position, they cut draughts, improve safety and help keep the building warm.

The commonest mistakes in choosing and fitting

The commonest mistakes are: choosing too weak a model for a heavy door; skipping the latching adjustment, so the door fails to engage the latch; over-tightening the valves, risking an oil leak; and fitting that departs from the manufacturer’s template. The adjustment valves are sensitive and need a gentle hand.

In summary

A well-chosen, well-adjusted closer means years of quiet, reliable service from a door. If you are not sure which model to pick, get in touch. At the TECHNOLOG wholesale, trading since 1994, we will help you choose a closer with the right force and features for your door, and we deliver anywhere in Poland.