When a major plumbing project is involved, get 3 or more bids and get a written contract prior to beginning work. Ask for, and inspect, local references. The contract should specify the type of work to be performed, total charges, permitting, warranty coverage, the completion date, brand names of fixtures, and the condition in which the plumber will leave the house. Do not make the final payment until the project is finished. Be sure to get a receipt for money paid.
PermitsPermits must be issued before any plumbing can be installed, altered, removed, replaced, or repaired. Permits for performing plumbing work are issued only to licensed plumbers. A permit is not required for minor repairs such as fixing a leaky faucet, valve or other working part of a plumbing fixture, or for clearing a blocked drain because these minor repairs do not include replacing or relocating a faucet, valve or other working part of a plumbing fixture, or water supply, sewer, drainage, soil, waste, vent or similar piping, or any work which may affect the public health. Ask to see the permit before work begins.
LicensesVerify the plumber's license. Call the Board of State Examiners of Plumbers and Gas Fitters at 617-727-9952 to verify licensure, the number of years licensed, and the licensee's disciplinary history. A master or journeyman plumber's or gas fitter's license type and number must be shown on any sign, listing, or advertisement.
Any person licensed as a master or journeyman plumber may perform the work of a gas fitter, but a licensed master or journeyman gas fitter may not carry out the work of a plumber.
A master plumber has worked for a minimum of one year as a journeyman, completed 100 hours of advanced plumbing theory, and successfully passed the master plumber examination. A master plumber may work either as an individual, a firm, or a corporation. A master plumber must maintain a regular place of business where the current license is displayed. The master plumber may employ journeymen and apprentices. A journeyman plumber has worked for three years as an apprentice, completed 300 hours of theory at an institution approved by the Department of Education and the Board of State Examiners and successfully passed the journeyman examination. A journeyman works as an individual in performing plumbing work. State regulations require that a journeyman carry a license and display it upon request.
An apprentice plumber is a person learning the trade who is registered with the Board and works under the direct supervision of a master or journeyman plumber.
Please see following info--
http://www.mass.gov/?pageID=ocaterminal&L=5&L0=Home&L1=Government&L2=Our+Agencies+and+Divisions&L3=Division+of+Professional+Licensure&L4=Consumer+Fact+Sheets&sid=Eoca&b=terminalcontent&f=dpl consumer factsheet pl&csid=Eoca