Nassau County & western Suffolk
Leak Detection & Repair on Long IslandHidden Leaks, Wet Spots, High Bills
All Island Plumbing, Heating & Cooling is a plumbing company at 5788 Merrick Rd, Suite 203, Massapequa, NY 11758, finding and fixing water leaks across Nassau County and the Towns of Huntington, Babylon and western Islip. Call (631) 644-2084. We answer calls 24/7 and are open Monday through Saturday (closed Sunday).
Smell gas? Leave the house first, then call the gas utility's emergency line or 911.
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- Local office · Merrick Rd, Massapequa
- Nassau County & western Suffolk
- Licensed & insured across Long Island
- Answering calls 24/7 · Open Mon–Sat, closed Sunday
Not every leak drips where you can see it. A water bill that jumps, a damp patch that never dries, a warm spot on a slab floor or the sound of running water when everything's off can all mean a hidden leak in a supply line or a drain.
What we do
- Find hidden supply leaks inside walls, ceilings, crawl spaces and under slab floors
- Find leaking drains, toilet seals and shower pans
- Repair or replace the leaking section of pipe
- Repair leaks on your side of the water meter, including the service line on your property
What we don't do
- Repairs to the water main or the curb valve, which belong to your water supplier
- Mold remediation or drywall and flooring restoration after a leak (we fix the plumbing)
How it works
- Check the meter. With every fixture off, a meter that keeps moving means water is leaving the pipes somewhere.
- Narrow it down. We isolate sections of the plumbing to find whether it's the service line, the supply piping in the house, a fixture or a drain.
- Open only where needed. The goal is to find the spot before anyone breaks into a wall or a floor, then repair it.
Who owns which leak
On Long Island the line from the water main to your meter is split between you and your water supplier, and the split depends on the supplier. The South Huntington Water District's ordinance, for example, says the district maintains the service up to the property line, and from the property line in, including the meter pit, the line is the owner's. The Dix Hills Water District has its own rules for who may work on service pipes. Call your supplier first for a leak in the street or at the curb.
Lead and old galvanized service lines are part of the same question. Water suppliers have filed service line inventories with the state. Mineola's lists 552 lead lines, 474 of them on the customer side, and Garden City issued a lead notice in July 2025. Ask your supplier what your inventory entry says.
Slab houses
Levittown's houses were built on concrete slabs with no basement, and some lines run under or inside the floor. In a slab house, a warm spot on the floor, a hissing sound or a jump in the water bill are the usual signs. That's a leak to locate before anyone breaks concrete.
Where
Leak Detection & Repair near you
Town pages with local facts for this service, plus every community we serve.
Other plumbing services
Questions
Leak Detection & Repair FAQ
My water bill doubled and I can't see a leak. What should I check?
There's a wet spot on my ceiling under the bathroom. Is it the pipe or the shower?
Who fixes a leak between the street and my house?
Sources:South Huntington Water District, Water Ordinance (2017); Dix Hills Water District, Consumer Handbook; Village of Mineola service line inventory (filed with NYSDOH, Oct. 2025); Incorporated Village of Garden City, 2025 Annual Water Quality Report and lead action level notice (July 2025); Wikipedia, "Levittown, New York" (slab construction).