Electric and Hydraulic Headsail Furlers: Care, Manual Override and Safety

Most damage comes from operating errors.

• Ease the sheet before you furl and keep a little tension on it so the sail rolls tightly. Seldén's built-in current limiter cuts torque if you try to furl with the sheet still made fast, then resets a few seconds after you let go of the button.
• Release the furling brake or lock first, if your system has one.
• Watch the sail while the motor runs. If it stops or slows, let go of the button and find out why (a riding turn, a jammed sheet or a halyard wrap) instead of holding the button down.
• Don't keep cycling after a stall. Repeated stalls heat the motor and trip the breaker.
• Reef early. A button makes reefing so easy that it's tempting to wait. BoatUS's roller-furling article reminds sailors that a furler doesn't change the old rule of reefing too soon rather than too late, and that it stays a simple one-person job only if you don't let the wind get too strong first. Harken adds that after reefing, moving the genoa lead car forward keeps the reefed sail's shape, and that a sail built for reefing on your furler works best.

Do this on a calm day, before you ever need it.

• Turn off the furler's breaker first. Harken warns that if the power is on, the motor could start and spin the drill.
• Harken: remove the cover on the manual-drive socket, then use the supplied crank handle, or a cordless drill with the supplied adapter. A winch handle also fits but is slower and harder. Harken says not to rely on the drill alone as your emergency drive.
• Seldén Furlex Electric: an emergency line-driver comes as standard, and an emergency handle is an option.
• Furlex Hydraulic: can be furled by hand with an ordinary winch handle.

Write the steps on a card, keep the tool in a known place, and practice a full furl by hand at least once a season.

Salt crystals and grit wear swivel bearings and attack aluminum. After salty sailing and before layup, gently rinse the drive housing, drum or tack area, foil and halyard swivel with fresh water and mild soap, then rinse well. Use a low-pressure hose; don't blast water into seals, electrical connectors or switch housings.

With the sail down (or the halyard eased), turn the tack swivel and halyard swivel by hand. They should spin smoothly without grinding. Gritty or stiff swivels make the motor work harder; flush them as the maker describes and lubricate only where the manual says to. Check the halyard leads at a proper angle from the swivel to the mast, since a halyard wrap can jam the furler and damage the forestay. See the roller furler guide for more.

With the power off, look over the motor and gear housing:

• Paint blistering, white powdery corrosion or bubbling at screws or seams
• Loose or missing cover screws and a damaged manual-drive cover
• Cracks or wear at toggles and link plates
• Signs of water inside if there is an inspection point

Harken says its gears are permanently lubricated and sealed with double-lip seals; don't open a sealed gearbox yourself. Report leaks or noises to a rigger.

Most electric furler faults are wiring faults.

• Check the cable where it passes through the deck or into the anchor locker. Gland seals should be tight, and the cable should not chafe on chain, the windlass or the locker edge.
• Look for green corrosion at connectors and terminals. Clean and protect them as the maker allows.
• Make sure the cable is secured, not hanging where the anchor chain can snag it.
• Feel the cable after a long furl; it should not be more than slightly warm.

Many installs share the windlass cable run to the bow (Harken notes this is common). That's fine if the wiring was sized for it, but check both circuits.

• The breaker protects the motor and wiring. Facnor supplies a specific marine breaker that trips if the motor overheats.
• Make sure someone can cut the power fast. The breaker or isolator should be reachable from the cockpit or close to it, and everyone aboard should know where it is. In a fatal 2025 accident investigated by the UK's MAIB, an electric winch had a known fault that let the motor keep running after the switch was released, and the only way to stop it was an isolator in the forward cabin. If your furler ever keeps turning after you let go of the button, or starts on its own, kill the power and don't use it until a marine electrician has found the fault.
• Never replace it with a bigger breaker to stop nuisance trips. Find the cause: stalls, a dragging swivel, a halyard wrap, low battery voltage or a wiring fault.
• Open the control box or relay box only with the power off and only if the maker allows. Look for corrosion, loose terminals and water.
• If the breaker trips under light load, have a marine electrician check the wiring and motor current draw. Seldén quotes a normal draw of roughly 10 to 25 amps for Furlex Electric.

Press each switch in both directions. Cockpit buttons should have intact rubber covers; cracked covers let water in and cause stuck or dead buttons. Replace wireless remote batteries every season and keep a wired switch as backup if your system has one. On Furlex Electric, one button runs slowly and pressing both doubles the speed, so make sure everyone knows how yours works.

Have a helper run the furler while you measure voltage at the battery and, if accessible, at the control box. A big drop points to undersized wiring, a bad connection or a weak battery. Run the engine or charger during long furling sessions if your maker recommends it.

With the system shut down, check the fluid level at the power pack and top up only with the fluid the maker specifies. Look for weeping fittings, chafed hoses and oil stains below the furler or in the locker. Leaks, a sinking sail under load, or slow, jerky furling need a hydraulic technician.

At the dock in light wind, unfurl and furl the whole sail. Listen for grinding, clicking or uneven speed, and watch for the foil twisting unevenly (top lagging behind the bottom). Try a partial reef and check it holds. Seldén and Harken use self-locking worm gears so a reefed sail doesn't unfurl under load.

Remove the sail if you can (it reduces strain and UV damage), rinse the unit, turn off the breaker, and cover the switch if it is exposed. In spring, check the wiring and switches again, practice the override, and run a full test before your first sail.