How do I fit a door closer or check it?

A door closer is a straightforward fitting job with one genuinely important decision — the power size — and two adjustments that people commonly confuse for each other.

Safety

What you'll need

• Overhead closer of the correct power size, with its template
• Drill and bits suited to the door and frame material
• Screwdriver and an Allen key for the valves
• Spirit level and pencil

Step by step

1. Choose the right power size.Closers are rated by power size against door width and weight, typically EN 2 to EN 6. Too weak and the door will not latch; too strong and children and older people cannot open it. Fire doors normally need EN 3 as a minimum.
2. Consider an adjustable-power closer.Many cover a range of sizes with a spring adjustment. Worth it where the correct size is uncertain, and it lets you soften a door that turns out too heavy to open.
3. Work out which side it goes on.Standard fitting is on the pull side of the door with the arm to the frame. Push-side fitting needs a different arm arrangement and often a bracket, and it is the usual reason a closer will not work as fitted.
4. Use the template supplied.It is printed for that specific model and gives the hole positions relative to the hinge. Marking by eye or from another closer is how closers end up binding.
5. Fix into something solid.A closer works against a lot of leverage. Into the door's stile or lock block, and into the frame timber rather than architrave. A hollow-core door needs a fixing plate.
6. Set the arm to a right angle when the door is closed.Adjust the arm length so it is roughly perpendicular to the door with the door shut. This gives the closer its proper mechanical advantage and is what most badly fitted closers get wrong.
7. Understand the two valves.One controls the main closing speed across most of the swing; the other controls the latching action over the last 10 to 15 degrees. They do different jobs and adjusting the wrong one is the usual confusion.
8. Set the closing speed first.Slow enough to be safe and quiet — five seconds or so from 90 degrees is reasonable. Adjust in quarter turns and test between each.
9. Then set the latching speed.Slightly faster over the last few degrees so the door pushes properly onto the latch. Too fast and it slams; too slow and it stops short and does not close.
10. Never open more than a quarter turn at a time.Backing a valve out too far can let the hydraulic fluid escape, which finishes the closer. Small adjustments, always.
11. Check it closes fully from every angle.From fully open, from 45 degrees, and from just ajar. On a fire door it must latch from all of them — that is the actual regulatory test.
12. Use a backcheck if it is fitted.A third valve on some models that resists the door being flung open into a wall. Useful in a windy hallway and often left unset.
13. Leave fire doors alone otherwise.Do not wedge, disable or remove a closer on a fire door. In a shared or rented building that is a serious matter as well as a dangerous one.

Tips

• Get the power size right first. Everything else is adjustment; the wrong size is a replacement.
• Quarter turns on the valves, testing between. Winding one right out can dump the hydraulic fluid and end the closer.
• If a door closes almost all the way and stops, that is the latching valve, not the closing valve.

Common mistakes

• Fitting a closer that is too powerful — The door becomes hard for children, older people and anyone carrying something to open, which is both a nuisance and a safety issue. Use the rated size for the door.
• Opening a valve too far while adjusting — Hydraulic fluid can escape and the closer is then finished. Adjust in quarter turns and never wind a valve right out.

If it doesn't work

Questions people ask