Written by Randy Racioppi, founder of Atlantic Pool Leak Detection, with more than 15 years of experience locating pool leaks throughout New Jersey and Staten Island.
A pool that begins losing water after it has been winterized should not be ignored until spring. The first priority is to confirm that the pool water is actually dropping, protect the winter cover and pool from possible damage, and determine whether winter leak detection is practical.
This situation is different from knowingly closing a pool that was already leaking. If a pool is known to be leaking, the leak should be detected and resolved before the closing, even if it means rescheduling your appointment with your pool service company. This article addresses water loss that is first discovered after the pool has already been closed.
First, Confirm That the Pool Water Is Dropping
Water may collect on top of a solid safety cover after rain or melting snow. That water is separate from the water inside the pool. Before assuming the pool is leaking, make sure the level beneath the cover has actually fallen.
Inspect the pool only from a safe location. Never walk onto a safety cover, stand on accumulated snow or ice, or loosen an anchored cover simply to check the water level. If the water cannot be viewed safely through an opening or from the pool edge, contact the company that closed the pool.
If possible, document the water level against a fixed point and photograph it. Recheck it after several days. A continuing decline is stronger evidence of a leak than a single observation.
Check the Cover Pump and Discharge Hose
On a solid cover, a cover pump should remove water from the top of the cover only. Inspect the cover for holes that may allow pool water to be pumped out of the pool accidentally. If the pump remains plugged in throughout the winter, it may continue running and gradually pump water out of the pool without the homeowner realizing it. Also confirm that the pump is positioned properly and that the discharge hose is not creating a siphon.
Each spring, Atlantic Pool Leak Detection encounters pools that were unintentionally pumped down over the winter and initially believed to be leaking. Before assuming the pool has a leak, confirm that the water loss was not caused by the cover pump or discharge hose.
Do Not Blindly Add or Remove Water
Adding water may temporarily restore support beneath a safety cover, but it does not solve an active leak. Adding too much water may raise the water above the pool’s proper winterized level, allowing water to enter the skimmer or other areas that were intended to remain dry.
Do not pump additional water out of the pool unless a qualified pool professional directs you to do so. Contact the company that closed your pool or a pool leak detection specialist before making a large water level adjustment. The correct response depends on the pool type, cover type, current water level, winterization method, and suspected leak location.
Why a Winterized Pool Can Still Lose Water
Winterization may isolate plumbing lines that were properly blown out and plugged, but it does not seal every part of the pool. Water can continue escaping through a vinyl liner, pool shell, skimmer body, light niche, main drain, fitting, step area, or other areas below the waterline.
The level where the water slows or stops can provide a clue, but it does not prove the exact source or location of the leak. As the water level drops, reduced water pressure may slow the rate of water loss – or even stop it. In a vinyl liner pool, dirt or debris can also become lodged in a hole and temporarily slow or stop the leak. For these reasons, the water level may stabilize even though the leak has not been located or repaired.
Protect the Safety Cover
The water inside the pool helps support a safety cover when snow and ice accumulate. If the pool water drops too far below the cover, the cover, straps, springs, anchors, and surrounding deck may be forced to carry additional strain.
Do not walk on the cover or attempt to push heavy snow through it. Follow the cover manufacturer’s maintenance instructions and contact the installer if the cover is sagging, overstretched, pulling at anchors, or no longer properly supported.
Can a Closed Pool Be Tested During Winter?
In some situations, yes. Winter leak detection may be possible when the pool is safely accessible, the water is not frozen, weather conditions allow testing, and the cover can be opened or partially removed without damage.
The appropriate testing depends on the symptoms and the way the pool was winterized. It may include checking accessible underwater components, dye testing a suspected area, inspecting the liner or shell, or evaluating plumbing that can be tested without compromising the winterization.
Severe cold, ice, snow, an unsafe cover, or inaccessible equipment may limit what can be done immediately. A professional should explain whether testing can proceed, whether temporary protective steps are needed, or whether conditions must improve first.
Do Not Wait Without a Plan
Low water can damage a vinyl liner, reduce support for a safety cover, expose a plaster finish, or create structural risk in an empty pool. The complete explanation of those risks is in our separate guide about why a known pool leak should be resolved before closing.
If the pool is losing water after closing, record the level, check the cover pump, avoid unsafe access, and contact a professional. Waiting until spring without monitoring the pool can allow a manageable problem to become much more costly.
Contact Atlantic Pool Leak Detection
Atlantic Pool Leak Detection provides professional pool leak detection throughout New Jersey and Staten Island. When contacting us, explain the pool type, cover type, current water level, estimated rate of loss, closing date, and whether the water appears to stop at a particular height.
New Jersey homeowners can call 732-333-3304. Staten Island homeowners can call 718-532-4880 or use the contact form to request an evaluation.
Frequently Asked Questions
Should a covered pool lose water during winter?
A continuing decrease in the pool water level should be investigated. Water on top of a solid cover and water inside the pool are separate, so confirm which level is changing before assuming there is a leak.
Can evaporation lower the water under a winter cover?
Some evaporation may occur, especially with mesh covers and changing weather, but a noticeable continuing drop should not automatically be blamed on evaporation.
Should I add water to a leaking pool during winter?
Do not make a large adjustment without guidance. The proper level depends on the pool, cover, and winterization. Adding water may provide temporary support, but it will not repair the leak.
Can winter leak detection be performed without opening the pool?
Sometimes, but access and weather determine what can be tested. The cover may need to be opened or partially removed, and frozen water or unsafe conditions may delay testing.
What information should I provide when calling?
Provide the pool and cover types, the current water level, how quickly it is dropping, when the pool was closed, whether a cover pump is being used, and any level where the loss appears to slow or stop.
