Short answer: Plan on getting a permit. The Town of Brookhaven (which covers Centereach, Selden, Coram, Farmingville and Port Jefferson Station) exempts only "minor repairs to existing plumbing systems" from a building permit, and its code does not include the state's optional exemption for replacing equipment like-for-like, so a water heater swap goes on a building permit application with the Town's Plumbing Worksheet (the "Heating/Hot Water" box).
The short version
- Brookhaven hamlets (Centereach, Selden, Coram, Farmingville, Port Jefferson Station): Town of Brookhaven Building Division, Farmingville.
- Incorporated villages (Lake Grove, Port Jefferson and others): the village building department, not the Town.
- Town of Smithtown: Smithtown Building Department, which takes "Plumbing Only" and heating-unit applications online.
- Split hamlets (Ronkonkoma, Holbrook): your tax bill shows which town you're in.
Why a swap isn't automatically exempt in Brookhaven
New York's rules for local building departments (19 NYCRR 1203.3) list categories of work a town may exempt from permits, but only if its own code says so. One of those optional categories is "replacement of any equipment provided the replacement does not alter the equipment's listing or render it inconsistent with the equipment's original specifications."
Brookhaven's building code (Chapter 16, §16-3) lists its exemptions, and that equipment-replacement category isn't among them. Its list covers small sheds, awnings, finish work like painting and tiling, portable listed appliances, and repairs that don't affect fire and life safety. A water heater is permanently connected to water, venting and usually gas, so it isn't portable. Separately, the zoning chapter (§85-12(B)) says no permit is needed for "minor repairs to existing plumbing systems," but the code doesn't define "minor."
The practical reading: treat a water heater replacement as permit work, and if you think your job is only a minor repair (say, a new thermostat or valve on the existing heater), ask the Building Division before skipping the permit. An exemption never makes non-code-compliant work okay; §16-3(B) says so directly.
What the Brookhaven application asks for
- Building permit application plus the Plumbing Worksheet, which the Town says is required "if the project includes any type of plumbing work." The worksheet has a "Heating/Hot Water" box to check, and separate boxes for gas line extensions and oil-to-gas conversions.
- Riser diagram if piping changes: the worksheet says "any new or altered piping requires a riser diagram," and the application lists a riser diagram for gas lines.
- Manufacturer's equipment specifications for equipment being installed, where applicable.
- Who signs: the worksheet says an owner's signature "is only for an existing residential dwelling," and new construction must have a plumber's signature. If a plumber does the work, the worksheet asks for their Suffolk County Consumer Affairs license number and its expiration date.
- Workers' comp and disability forms for the person doing the work, or a CE-200 exemption form if the homeowner does it.
How to file in 2026
Brookhaven moved its Building Division to an online Digital Services portal in fall 2026 and no longer accepts drop-offs. Applications from expeditors or licensed professionals, such as a plumber filing for you, must go through the portal. Property owners filing their own residential application can still ask for a paper application at Town Hall, as long as every plan and document is on 8½ by 11 inch paper.
The Building Division is at 1 Independence Hill, Farmingville, 631-451-8696. Hours are 9:00 AM to 4:15 PM weekdays through October 30, 2026, then 9:00 AM to 3:30 PM starting November 2.
Once issued, a Brookhaven building permit expires 12 months after issuance unless the Chief Building Inspector allows longer (§16-3(H)), and it must be posted visibly at the work site until the work is done (§16-3(F)).
What if work is done without one?
Brookhaven's code allows a fine of up to $125 per day of violation, or a civil penalty of up to $125 per day, and the Town can issue stop-work orders for permit work done without a permit (§16-8, §16-9). Unpermitted work can also surface later, for example when you sell and the buyer's side checks the Town's records.
Smithtown and the villages
The Town of Smithtown's permit application covers heating equipment for "domestic hot water," with boxes for new, conversion and replacement, and Smithtown residents can apply online for "Plumbing Only" or "Air Conditioning/Heating Unit/HVAC" permits. Smithtown's fees are set in Town Code §112-11; ask the Building Department (23 Redwood Lane, 631-360-7520) which line applies to your heater. If you live inside an incorporated village such as Lake Grove, call the village building department instead of the Town.
Questions to ask the plumber
- Will you pull the permit, or should I? (If they file, it goes through Brookhaven's online portal.)
- What's your Suffolk County plumbing license number? You can check it with the County's free lookup; see our guide on checking a plumber's license.
- Are you changing any gas, water or vent piping? If so, a riser diagram is needed.
- Is the new heater the same fuel and type? Switching fuel (for example oil to gas) is a separate box on the worksheet.
Sources
- Town of Brookhaven Code, Chapter 16, Building Construction Administration (§16-3 permit requirement and exemptions; §16-3(B) exemption is not authorization for noncompliant work; §16-3(F) display; §16-3(H) 12-month term; §16-8 penalties up to $125/day; §16-9 stop-work orders)
- Town of Brookhaven Code, Chapter 85, Article II, §85-12(B) (no permit for minor repairs to existing plumbing systems)
- Town of Brookhaven, Building Permit Application (Plumbing Worksheet if any plumbing work; riser diagram for gas lines; equipment specs; workers' comp, disability, CE-200)
- Town of Brookhaven Plumbing Worksheet, rev. 03/23/2026, as included in the Town's permit packet (Heating/Hot Water box; new or altered piping needs a riser diagram; owner signature only for an existing residential dwelling; plumber's Suffolk County license number and expiration)
- Town of Brookhaven, Building Division (Digital Services portal, no drop-offs, owner paper applications on request, address, phone, hours)
- New York State, 19 NYCRR 1203.3 (optional local permit exemptions, including like-for-like equipment replacement)
- Town of Smithtown, Online Residential Building Permits, Application for Permit to Build or Install, Town Code ch. 112 (§112-11 fees) and Building Department contact page
General information, checked against Town of Brookhaven, Town of Smithtown and New York State pages on Oct 27, 2026. Only the building department for your address can say whether your specific job needs a permit.
Common questions
Do I need a permit to replace a water heater in Centereach?
Plan on yes. Centereach is in the Town of Brookhaven, whose code exempts only minor repairs to existing plumbing and does not include the state's optional exemption for like-for-like equipment replacement. The job goes on a building permit application with the Plumbing Worksheet (Heating/Hot Water). Confirm with the Brookhaven Building Division if you're unsure.
Can a homeowner pull the water heater permit in Brookhaven?
The Town's Plumbing Worksheet allows an owner's signature for an existing residential dwelling; new construction needs a plumber's signature. Owners can still ask for a paper application at Town Hall, while plumbers and expeditors must file through the Town's online Digital Services portal.
Does a tankless or gas water heater need anything extra?
If gas, water or vent piping is new or altered, the Brookhaven worksheet requires a riser diagram, and the application lists a riser diagram for gas lines. Switching fuel, such as oil to gas, is a separate box on the worksheet.
What happens if I replace a water heater without a permit in Brookhaven?
The Town Code allows fines or civil penalties of up to $125 per day of violation and stop-work orders for permit work done without a permit.
I live in Lake Grove or Smithtown. Is it the same?
No. The Village of Lake Grove has its own building department, and the Town of Smithtown handles its own plumbing and heating permits, including online applications. Check with the department for your address.
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