Check which window type you have before you touch a screw, because several types cannot be adjusted at all. On the ones that can, three separate things are adjustable: the friction that holds the sash open, the receiver that decides how tightly it closes, and the handle. Match the symptom to the right one and most jobs take ten minutes.
Start here. Adjusting the wrong type wastes an afternoon, and three of the window types we supply have no adjustment at all by design.
If yours is one of the three that cannot be adjusted, that is not a fault and not a dead end. The receiver, the weather stripping and the handle are all still available to you, and those cover most of the complaints people describe as needing adjustment.
Identify your type by how it opens. A top guided window swings out at the bottom and the top of the sash slides down. A reversible one rotates 180° so you can clean the outside from indoors. A side hung window swings on one side like a door. A side guided one slides sideways as it opens, leaving a gap for cleaning.
Six complaints cover almost everything, and each one points at a different part.
Two of these are worth separating in your head, because mixing them up is the most common mistake. Friction decides whether the sash stays where you put it when the window is open. The receiver and the espagnolette decide how tightly the sash pulls into the frame when it is shut. A draught is never a friction problem, and a sash that drops open is never a receiver problem.
Friction is what holds the sash at the angle you leave it. Too slack and the window swings or falls. Too tight and you fight it every time.
The adjustment is a screw in the slide block on each side of the sash. Open the window, find the block where the arm runs, and turn the screw to increase or reduce the friction.
Tighten both sides by the same amount. This is the rule that matters most, and our own product guide states the reason: unequal tightening warps the sash. A warped sash then leaks, catches the frame, and creates a second problem while you were fixing the first.
Work in small increments. A quarter turn, then open and close the window and check how it holds. Repeat rather than guessing at a final setting.
On a side hung window with a slack brake, the same principle applies through a single adjusting screw on the brake at the bottom of the sash. On a side guided window, the adjustment sits in the top hardware rather than at the sides.
Before adjusting anything, check which slot the window is closed onto. Some receivers have two slots: the inner one closes the window, and the outer one holds it in a fresh-air ventilation position.
A window latched onto the outer slot looks shut and is not. It is the single most common cause of a "draughty" window that seemed fine last week, and the fix takes seconds.
Once that is ruled out, three things remain.
The receiver. Closing tension is set by how the roller bolts meet the receivers on the frame. Where the sash does not pull in evenly, the receivers are the part to look at rather than the friction.
The weather stripping. Run a finger along the strip in the groove around the sash perimeter. Soft and flexible is healthy. Hard, flattened or cracked means it has perished, and no adjustment recovers it. Our product guide is explicit that weather stripping should not be removed, so treat replacement as a job to ask us about rather than a strip to pull out.
The clearance. The air gap between frame and sash should be the same at the top and at both sides. Uneven clearance points at the frame rather than at the sash, which is covered below.
One safety note carried over from our own guide: never leave the house with a window latched in the ventilation position.
A sash that catches on one side, or shows a gap that is wider at the top than the bottom, usually has a clearance problem rather than a friction problem.
Correct clearance means the air gap between the sash and the frame measures the same at the top and down both sides.
Where it does not, the frame is the likelier culprit, and our own installation instructions set the standard: the frame has to be plumb, level, and square, with equal diagonal measurements corner to corner.
Check the diagonals of the frame with a tape measure. A difference of more than a few millimetres means the frame is out of square, and no amount of adjustment at the sash will correct it.
This matters commercially as well as practically. Our warranty does not cover units installed out of plumb, out of level or without equal diagonals, and it does not cover units fixed with foam alone.
A window that will not come right is worth diagnosing as a fitting question before it is treated as a hardware question.
Yes, and it is one of the simpler jobs on a window. The handle drives the espagnolette, the locking bar that runs inside the sash and throws the bolts into the receivers, so a broken handle usually means a broken handle rather than a broken mechanism.
Two things to get right. Spindle length and handle type have to match the espagnolette you already have, so take the old handle with you or photograph it alongside a tape measure. And handedness matters on some designs, because a side hung window can have the handle on either side of the sash.
Before replacing a handle that has become stiff, lubricate the mechanism first. Our guide specifies all-purpose oil on hinges, handles, rivet joints, espagnolettes, slide bars, roller bolts and locks, at least once a year. A gritty handle is often a dry espagnolette rather than a failing one.
If the handle turns freely without throwing the bolts, the espagnolette itself has failed, and that is a replacement rather than an adjustment.
Five things cause more damage than the fault being fixed.
The first is worth expanding, because it runs against most advice you will find. Plenty of maintenance guides recommend spraying every hinge and moving part. On windows fitted with friction brakes or concealed reversible hardware, our product guide is specific: the slide rails stay clean and free of both oil and paint. Lubricant on a friction rail defeats the friction, which is the thing holding your window open.
The second is a mechanical one. On a side hung window with a handle-controlled brake, the handle locks the brake into position. Forcing the window closed against a locked brake is how brakes break.
Adjusting hardware does not put your cover at risk. Our warranty terms treat finishing details such as minor planing and hardware adjustment as outside the scope of the warranty, which means they are normal owner maintenance rather than warranty events.
The reverse is worth knowing too. Cover excludes damage caused by incorrect installation, insufficient maintenance and incorrect operation. A window installed out of square, or one that was never lubricated, sits outside the warranty for a different reason.
Two situations where you should contact us rather than reach for a screwdriver. A window that misbehaves within weeks of installation, because that usually points to a fitting issue worth diagnosing properly. And any fault involving the sealed glazing unit, where cover comes through the glazing manufacturer under a separate arrangement.
For anything else, annual lubrication and small seasonal corrections are exactly what the adjustment screws exist for.
