My Winterized Above Ground Pool Is Leaking

Evaporation

• You will lose water due to evaporation. Even though the pool is covered, the air bubbles beneath the winter cover create a gap between the water and the cover. The evaporation will not happen as fast as when the pool is covered, but over the course of six months, you should expect to lose some water in the pool. It can be difficult to determine how much because there are many variables to consider.

Skimmer Cover

• Use a skimmer cover plate, which can be applied by two methods. Some covers are plastic and snap on like a cover for a plastic storage container. This type of cover can warp over the years, and as a result the seal between the skimmer and the cover can leak. The skimmer plate that screws onto the face of the skimmer is more reliable, but the gasket that seals the plate to the pool skimmer can also fault, leading to a leak. This issue can damage the pool liner and structure if the water freezes and expands.

Check Plugs

• The leak can also be the result of a loose return jet plug. Besides the vinyl liner, this is the only other place the pool can leak from. Loosen the cover to access the plug. Tighten the plug by turning it clockwise. The plug may have loosened from pressure or from water expansion due to freezing in the outlet. Unless water is gushing from the plug, it is probably best to tighten the plug and replace it at the end of the season.

Other Leaks

• A rip in the lining can cause a significant amount of water loss over the course of the winter season. If you have a slow but consistent leak, you can probably make it through the winter months. There's no way you are going to remove the winter cover and head into freezing water to search for a tear in the vinyl lining. If you suspect a leak in the lining, replace the lining before you close the pool for the winter. A sign of a major leak during the winter is puddling water around the base of the pool. This means the water is leaking considerably and the cold water may have made a slight tear in the lining worse. Remove the water from the cover, and loosen the cover to relieve pressure on the pool walls. Repair the cover immediately.