N.Y.C. Admin. Code § 28-105.4.4: § 28-105.4.4 Ordinary plumbing work.

The following ordinary plumbing work may be performed without a permit, provided that the licensed plumber performing such work: (i) provides a monthly report listing completed work and work in progress during the preceding month, including the block, lot and address of each job, a description of the work performed or in progress at each address, and the location in each building where the work was performed or is in progress; (ii) pays the fees for such work in accordance with this code; and (iii) submits to the department a certification that the work was performed in accordance with this code and all applicable laws and rules. Ordinary plumbing work shall include:

1. The removal of a domestic plumbing system not connected to a fire suppression or fire protection system, or the removal of a portion of such system.

2. The relocation of up to two plumbing fixtures within the same room to a maximum of 10 feet (3048 mm) distant from the original location, except in health care facilities.

3. The installation, replacement or repair of a food waste grinder (food waste disposal) or secondary back flow preventer and the replacement or repair of a sump pump.

4. The repair components of a plumbing appliance or plumbing appurtenance or the replacement of a plumbing appurtenance.

5. In buildings classified as residential occupancy groups occupied by five families or fewer, the replacement of a gas water heater, gas furnace, or a gas-fired boiler with a capacity of 350,000 BTU (103 kW) or less where the existing appliance shutoff valve is not moved, provided that the plumber has inspected the chimney and found it to be in good operational condition.

6. The repair or replacement of any non-gas, non-fire suppression piping not longer than 25 feet (7620 mm) inside a building, or connected piping previously repaired or replaced under this provision.

7. The repair or replacement of any non-gas, non-fire suppression branch piping after the riser shutoff valve, including the replacement of fixtures.

8. The replacement of an appliance connector serving the following domestic gas appliances: ranges, ovens, stoves, barbecues, and clothes dryers where the existing appliance shutoff valve remains and replacement shall be in accordance with this code and the New York city fuel gas code. The existing appliance shutoff valve shall be accessible and in good working condition with no noticeable corrosion or deterioration.

9. The replacement of the following domestic gas appliances: ranges, ovens, stoves, barbecues, and clothes dryers where the existing appliance shutoff valve remains and when such appliance replacement is in accordance with this code and the New York City fuel gas code. The existing appliance shutoff valve shall be accessible and in good working condition with no noticeable corrosion or deterioration.