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Serving the Hamptons since 1950


Renovations &

New Construction 

Includes bathrooms, kitchens, waste piping, vent piping, water piping, and more. Call our office to let us help you tackle your next project!

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Service & Installation of Plumbing &

Heating Systems 

If water runs through it, we do it! Contact us today to let us help you find an efficient solution to your plumbing & heating needs! 

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Harold McMahon Plumbing and Heating was established in 1950 by Harold McMahon Sr. Harold McMahon, Jr. has been at the helm for more then 35 years and has helped to bring the business forward to match the unique needs of every home on the east end of Long Island from Southampton to Montauk. We cater to customers with any need in the plumbing, heating, and cesspool line of work in both residential homes and commercial businesses and no job is too big or too small. Service and customer satisfaction is our primary concern.

Harold McMahon Plumbing and Heating has been a member of the Hamptons community for over 65 years. Our master plumbers and trained technicians have years of experience and keep up on certifications and training. We are proud to say most have been with us for over 20 Years. They and we are longtime members of the local community, dedicated to quality and enthusiastic about our profession – you can't find a finer organization to entrust with your project.



Deb C. 

El Cajon, CA | 6/1/2019

"I manage a home in East Hampton and did not have hot water. I thought I would have to purchase a new hot water heater. Harold and his associate came out within 1 hour (I called at 3:15), told me I did not need a new hot water heater. I needed a valve from the boiler to the hot water heater since the boiler was off. I didn't need the boiler to also heat my water. Yay, money saved. Thank you for coming out so I could have hot water that night and being very efficient and a pleasure to work with."

Kim R.

New York, NY | 8/10/2019

"We had an emergency plumbing situation in our Montauk house. We called Harold McMahon Plumbing, and they sent Mike over. He was extremely professional, very pleasant, and did an amazing job in record time. We couldn't be more pleased with him! He is our go-to plumber for any future issues, and we have already recommended him to three of our friends. Thank you for a job well done!"

Jay D. 

East Hampton, NY | 7/30/2020

"While writing reviews isn't something I ordinarily do, I wouldn't consider the service we just received as ordinary either. After an unexpected plumbing issue caused us to turn off the water to our house, we called Harold McMahon and Riley responded right away. He was friendly, knowledgeable, and pr, and took the time to do the job right. The comfort in knowing that a local company and its employees truly care sometimes doesn't get recognized enough, but I'm glad that in this instance I'm able to do just that."



For any inquiries, questions, and quotes, please leave a message or call us at 631-267-3471

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