Maintaining an electric opening mechanism

1. Clean the gasket

The most important one. Grit, leaves and moss on the compression seal stop the sash seating properly.

Two consequences: it lets water past, which gets reported as a leak, and the actuator works harder every cycle trying to compress against an obstruction, which shortens its life.

A wipe with a damp cloth is all it needs. Under trees, twice a year.

2. Lubricate the chain

A light spray on the chain where it extends from the housing. Dry chains get noisy and stiff, and stiffness is load on the motor.

Light oil or a dry PTFE spray. Not grease, which collects grit.

3. Wipe the rain sensor

A dirty sensor either misses rain, which defeats the point, or reads permanent moisture from grime and refuses to let the window open at all. The second is the more common complaint and it looks exactly like a fault.

4. Cycle it

Open and close it fully a few times a year even in winter. Mechanisms that sit unused seize, and a full cycle keeps the chain and the seals working.

What not to do

Force a sash that will not move under power. The chain is rigid and does not want to be back-driven, and forcing it damages the mechanism and sometimes the frame.

If it will not move, find out why.

Solar units

Add keeping the panel clean, since a dirty panel charges slowly. The battery is a consumable, typically several years, and replaceable.

Four jobs a year, and one of them matters most

A motorised rooflight asks very little, and the whole routine takes under half an hour. Done, it is the difference between an actuator lasting fifteen years and one lasting eight.

Cleaning the compression gasket

The single most useful thing on this list, and on a motorised unit it matters twice over.

Grit, leaves and moss collect on the compression seal around the sash. When they do, the sash cannot seat properly. Two consequences follow.

Water gets past, which is reported to us as a leak and is nothing of the kind. And the actuator works against an obstruction on every single cycle, which is a load it was not designed to carry repeatedly.

The second point is specific to motorised units and it is why this matters more on them than on a manual window. A person closing a window by hand feels the resistance and clears whatever is in the way. A motor does not: it simply strains and keeps going, and it does that twice a day for years.

Open the window fully, wipe the seal all round with a damp cloth, and check it is not split, hardened or displaced from its channel. Five minutes.

Lubricating the drive

The rigid link chain that extends from the actuator housing benefits from light oil or a dry PTFE spray once a year.

Not grease. Grease collects grit and turns into an abrasive paste, which is worse than nothing. A dry film or a light oil is what the mechanism wants.

Extend the chain fully to apply it, then cycle the unit a few times to distribute it and wipe off any excess so it does not drip.

Keeping the sensor clean

A small detector on the frame, and a source of a surprising number of unnecessary callouts.

A sensor caked in grime does one of two things. It misses rain, which means a wet floor. Or it reads permanent moisture from the grime itself and refuses to let the window open at all, which looks exactly like a fault in the motor.

A damp cloth is all it needs, and it is worth doing at the same time as the gasket so it is not forgotten.

4. Cycle it fully

Several times a year, including in winter.

Mechanisms that sit unused seize. An actuator that has not moved since August will be stiff in March, and a seized one is considerably harder to override manually than a well used one.

A full cycle also tells you something. Listen to it. A motor that is straining, running more slowly than it used to, or stopping partway and needing a second command is giving you early warning that it is approaching the end of its life. That is useful rather than alarming.

The rest, as for any rooflight

Clean the filter at the top of the sash, behind the removable strip. It clogs with dust over a few years, the trickle ventilation stops working, and the room gets damper without anybody connecting the two.

Clean the glass. On a centre pivot unit rotate the sash and lock it in the cleaning position, which is what the feature is for.

Look at the outside every few years and after storms, for lifted flashing edges, slipped tiles or rust staining that indicates a plated fixing failing.

On a flat roof unit, keep the perimeter clear and check the outlet the roof drains to, because standing water against a seal is what kills a flat roof installation early.

What eventually needs replacing

The actuator, at ten to fifteen years. It is the shortest lived component on a motorised rooflight, against twenty five for the glazing and considerably longer for the frame and flashings.

That is not a design fault. It is a mechanism with a motor, a gearbox and a chain, cycling in an environment that swings from freezing to very warm, and ten to fifteen years of daily use is a reasonable service life.

It is a serviceable part. It unbolts and a new one goes on, usually from inside the room in under an hour, for a fraction of the cost of a new window. Where we fitted the original installation the labour is covered by our workmanship guarantee within its term.

The battery, on a solar unit, good for several years and also replaceable. It does not fail suddenly: the unit becomes slower to respond and less able to cope with a run of dull days, which is clear enough warning.

Gaskets, at fifteen to twenty years, and their life depends almost entirely on whether they have been kept clean.

The manual override

Find out how yours works at handover, demonstrated rather than described, and keep whatever it needs somewhere memorable rather than in the packaging.

Most chain actuators have either a detachable crank that winds the chain in by hand, or a release that disengages the actuator so the sash can be pushed closed.

On a rooflight above reach the crank needs a pole, and a pole you do not own is not much use. Confirm you actually have whatever it requires, and confirm whether it can be reached from floor level.

The scenario to plan for is open when the power goes, and then it rains. A chain actuator holds its position mechanically, so a cut leaves the window exactly where it was: nothing falls shut and nothing springs open. Solar units are unaffected by a mains cut entirely.

What to keep with the paperwork

The model details of the window and of the actuator, and the position of the control unit on a mains system.

Identifying a fifteen year old actuator from a photograph is possible and it is a great deal quicker if the specification is to hand, and nobody will remember in fifteen years where the control unit was put.

That is also why the control unit should be somewhere accessible in a loft or a cupboard rather than buried behind plasterboard, and why we agree its position before the wiring is run.

What is not maintenance

Anything involving the flashing, the underlay collar or the covering. Those are installation details rather than serviceable parts, and if water is getting past them it is a fault rather than a maintenance lapse.

On work we did, that is what the ten year workmanship guarantee is for, and a motorised unit is covered on exactly the same terms as a manual one.

The annual cycle test

Run the unit fully open and fully closed, and pay attention to it rather than glancing.

Listen. A motor that hesitates before moving, labours partway through, or sounds different from last year is telling you something before it fails.

Watch the sash. It should move evenly and seat evenly on the gasket all round. A sash that closes tight on one side and leaves a gap on the other is out of square, and the actuator is fighting it every cycle.

What to clean

The gasket, wiped and checked for perishing, hardening or displacement. It is compressed on every cycle and it is what makes the unit weathertight.

The sill and drainage path, cleared of debris. Leaves and grit sitting at the bottom edge hold water against the seal, and that is the commonest cause of a sound powered unit starting to let water in after fifteen quiet years.

The rain sensor, wiped with a damp cloth. A dirty sensor either stops responding, which is the dangerous failure, or starts closing the unit in dry weather.

The chain path or spindle, cleared of anything that could obstruct it.

Lubrication

Only what the manufacturer names, and sparingly.

General purpose oil attracts grit, and grit in a chain or a spindle track accelerates wear rather than reducing it. A dry lubricant or a specified grease at the stated points is the correct approach.

Testing the backup

The task nobody does and everybody should.

Isolate the supply at the fused spur and operate the unit. If it moves, the battery is good. If it does not, the battery has reached the end of its life and needs replacing.

Backup batteries fail silently after a few years. The unit works perfectly on mains right up to the power cut when you need it.

Before assuming the motor has failed

Check the supply at the isolator. Replace the remote battery. Re-pair the remote to the unit.

A surprising proportion of dead rooflights are unpaired remotes or tripped circuits rather than failed actuators, and all three checks take five minutes.

The one prohibition

Never force a stalled unit by hand.

An actuator is geared, and driving a gearbox backwards under load strips it. A fault that might have been a pairing problem or a jammed sash becomes a replacement motor and a call out.

Where a model has a mechanical override, find out where it is and how it works before you need it.

Keeping the paperwork with the window

Actuator model, control system, pairing instructions and the backup battery type, recorded with the house paperwork.

Re-pairing a handset is a simple operation if you have the instructions and a guessing game if you do not, and it is the single most common cause of a rooflight that has apparently stopped working.