Garage door opener installation: sizing and fitting a new unit

Fitting an opener is straightforward on a door that is in good order and difficult on one that is not, which is why the first thing that happens is a check of the door itself.

The door comes first

With the opener disconnected, a properly counterbalanced door lifts easily by hand and stays roughly where it is left at waist height. If it slams down or floats up, the springs need attention before an opener goes on. An opener fitted to an unbalanced door is being asked to do the springs job, and the gear kit is what pays for it.

Sizing

Weight decides horsepower. A light single door is comfortable on a half horsepower unit; a double, an insulated three-layer door, a wooden door or a carriage-style door wants three-quarters. Drive type is chosen on the building rather than the door: belt where there is a room above the garage, chain where noise does not matter, wall-mount where the ceiling has to stay clear or a car lift is going in.

Rail length is the measurement people miss. A standard rail suits a seven-foot-high door. An eight-foot door needs an extension kit, and a taller opening needs a longer rail again, so the door height is confirmed before the unit is ordered rather than discovered on the ladder.

Fitting

The motor head is hung from the ceiling on struts, not on the drywall, and squarely in line with the centre of the door. The rail is fixed to the header above the opening. The door arm connects to a bracket on the top section, and on a lightweight door that section gets a reinforcement strut, because an unreinforced top panel will flex and eventually tear around the bracket.

The photo eyes go on the vertical tracks near the floor, facing each other, and their wire is run back to the motor head clear of anything that will pinch it. The wall console goes where an adult can reach it and a child cannot easily.

Setting it up

Travel limits tell the opener where the floor and the ceiling are. Force settings tell it how much resistance means an obstruction. Both are set on a balanced door, in that order, and then the safety reverse is tested against an obstruction on the floor. A door that does not reverse has not finished being installed, whatever the app says.

Remotes, keypads and any app pairing are set up last, and the manual release is shown to whoever lives there, because the moment to learn where the red cord is and what it does is not during a power cut.