Top 5 Door Closer Mistakes and How to Avoid Them

Door closers are among the most frequently replaced items in commercial buildings — not because they are poor quality, but because they are frequently installed incorrectly or maintained badly. Here are the five most common mistakes we see, and what to do instead.

1. Fitting the wrong power size

Every door closer is rated to a power size defined by BS EN 1154, from EN 1 (lightest) to EN 7 (heaviest). The correct power size depends on the door's width and weight. Too weak and the door won't latch reliably. Too strong and the door becomes difficult to open, creating an accessibility problem and putting excess stress on the mechanism. Most commercial fire doors on standard corridors require EN 3 or EN 4. Always check the manufacturer's selection table before specifying.

2. Setting the closing speed too fast

A door that slams shut is a liability — it can trap fingers, damage the door frame, and fail the latch repeatedly as the door bounces. The closing speed valve controls the rate at which the door swings from fully open to approximately 15 degrees before the latch, and the latch speed valve controls the final closing action. Both should be adjusted so the door closes firmly but smoothly. Most closers leave the factory set fast — always adjust before signing off the installation.

3. Using a wedge instead of a hold-open device

Wedging a fire door open is illegal and puts lives at risk. Fire doors must either be held open with an electromagnetic device connected to the fire alarm — which releases automatically when the alarm sounds — or kept closed at all times. A wooden wedge, doorstop, or tied-back arm provides no automatic release and can result in prosecution, insurance invalidation, and loss of life in the event of a fire.

4. Fitting to an incorrect surface

Most overhead closers can be installed in standard, top jamb, or parallel arm configurations. Each configuration uses a different arm and bracket arrangement, and fitting the wrong type results in incorrect geometry, reduced power efficiency, and premature wear. Always check which configuration is appropriate for the door and frame before ordering, and use the correct arm set for that configuration.

5. Ignoring the backcheck adjustment

Backcheck is the hydraulic resistance that slows the door as it approaches full open, preventing it from slamming into an adjacent wall or damaging the mechanism. On doors exposed to wind or high-traffic areas, failing to set the backcheck correctly causes repeated impact damage to the frame and the closer arm. Adjust the backcheck valve so resistance begins at approximately 75 degrees and increases as the door reaches full open.

Door Spares stocks door closers and accessories from dormakaba, GEZE, Briton, Axim and Exidor. Same-day despatch on orders placed before 2pm. Free delivery on orders over £100.