Why is my automatic pool cover not closing?

The short version: clear the path, check the water, then call

An automatic cover that stops or will not close is nearly always telling you about friction or load. The common culprits are debris in the track, water sitting on the cover, a pool that is too low, a tripped breaker or a stuck edge. You can check all of those safely from the deck. Anything involving the motor, wiring, ropes or a pulley belongs to the installer.

When the cover stalls, do not hold the switch. The manufacturer's guidance is that if the cover hesitates or stops before it reaches the end of the pool, you should immediately release the switch and investigate the problem.^[1]

Look for what is in the way

Sometimes dirt, debris, or obstacles like towels or hoses can stop the cover.^[1] Walk the length of the pool and check the cover path, the rails along each side and the gap where the cover leaves its housing. A pool toy or a skimmer pole under the leading edge is more common than any mechanical failure.

Then try the manufacturers' own trick. One says to remove any excess water or debris and try reversing the direction;^[2] the other says you should reverse the direction of the cover a foot or two and then retry to cover the pool.^[1] If it moves, carry on. If it will not move further in the intended direction, the Cover-Pools manual says to call your service technician.^[2]

Check the water, on and under the cover

Two water problems cause a lot of stalls.

Water under the cover is too low. One manufacturer says to maintain the water level at the middle elevation of the skimmer opening, and that if the water drops below this level, the cover may operate under stress.^[1] After a dry spell or a lot of backwashing, top the pool up first.

Water on top of the cover. The same troubleshooting chart lists "Water on cover" as a reason the cover will not move forward or reverse.^[1] A small submersible pump or a broom clears it. Do not run the cover over a heavy pool of water.

A third symptom looks similar: "Cover adhering to deck" is also on the list.^[1] After a wet spell or a hot day, the fabric can stick to the coping. Lifting the edge of the fabric a little to let air under it usually breaks the grip.

Power: a breaker or GFCI that has tripped

The chart's first cause of a cover that will not move is that the circuit breaker or GFCI is tripped.^[1] A GFCI must be used in the electrical supply line for the motor,^[1] so a trip can mean there is water in the wrong place. Resetting once is reasonable. A second trip means leave it off and call a technician. Resetting again and again only masks the fault.

Tracks and housings

Dirt in the tracks is the quiet cause of slow, noisy or stalled covers. The guide notes that in windy and dusty areas with blowing dirt, covers may become inoperable until the debris has been hosed from the tracks.^[1] "Debris in housing" is also listed as a cause of a cover running under strain.^[1] With the cover retracted, rinse the tracks and the pulley housings at the end of the tracks, and keep leaves out of the housing.

What to leave to the installer

The mechanism is heavy and wired to the pool's power. The guide itself warns: "Disconnect the breaker first if you attempt to service any movable part of the cover system."^[1] Its own approach is that a cover that will not retract or extend may need the torque limiter adjusted,^[1] but a limiter that keeps slipping means something is wrong elsewhere, usually a worn pulley or a binding rope. Uneven ropes, frayed webbing and a motor that hums without moving all call for a service visit. If the cover is not working you also have no safety barrier, and the CPSC's advice is to maintain pool and spa covers in good working order.^[3]

Stop and call a pro if

• The breaker or GFCI trips again after one reset.
• The cover stalls in the same spot after you have cleared the track and tried reversing.
• The motor hums, grinds or runs but nothing moves.
• Ropes, webbing or pulleys look frayed, worn or uneven.
• Water has got into the housing or the mechanism area.
• A fix would mean opening the housing, touching wiring or working on the mechanism.

Getting help in Virginia

For torn fabric, see how to repair a torn mesh pool cover, and for budgeting a service call read what pool cover repair costs in Virginia. Browse more pool and spa answers or pool maintenance pros near you.

When you want someone to look at it, describe the problem and local pros will quote it.