A Dependable Hot Water System Starts With Proper Installation, And Our Licensed Experts Ensure It’s Done Right.
A properly installed water heater is essential for comfort, safety, and efficiency. At NJM Mechanical & Contracting, we provide expert water heater installation and replacement services for homeowners throughout Long Island, Nassau County, and Suffolk County.
Whether your current unit is failing, outdated, or unable to keep up with your household’s needs, our licensed team delivers clean, precise installations backed by decades of experience.
Professional installation of gas and electric tank-style water heaters. We ensure proper venting, secure connections, and safety valve testing for reliable, long-term operation.
Energy-efficient, on-demand tankless systems installed with precision. We assess your home’s flow rate, gas supply, venting, and electrical requirements to ensure peak performance.
Proper installation of expansion tanks to regulate pressure and prevent future leaks or system strain.
Upgraded water lines, shut-off valves, venting systems, and gas or electrical connections as needed for safe operation and code compliance.
Fast response for homes experiencing leaks, no hot water, or failed systems requiring same-day replacement.
Expert Plumbing Solutions
Backed by Over 33 Years of Experience
Why Long Island Homeowners Trust NJM for Water Heater Installation & Replacement
Expert installation backed by licensed professionals, clean workmanship, and the highest safety standards.
Every installation is completed by trained professionals who follow all local codes and safety requirements.
Your installation is supervised by a Master Plumber to ensure proper setup, venting, and long-term reliability.
We install all major brands and water heater types, delivering tailored solutions for your home’s size and hot water demands.
We protect your home during the installation process and leave your space clean when we’re done.
No surprises. We provide clear estimates before any work begins.
Serving homeowners across Nassau and Suffolk County with reliable, high-quality plumbing solutions.
Water Heater & Boiler Safety Testing
Assessment of temperature controls, pressure relief valves, gas/water connections, and venting to prevent hazards and improve efficiency.
Fixture & Appliance Safety Checks
Inspection of water heaters, boilers, valves, shut-offs, and plumbing fixtures to ensure proper operation and safe performance.
Leak Detection & Line Evaluation
We use advanced diagnostic tools to locate leaks, pressure issues, corrosion, and worn components before they evolve into major problems.
Emergency Shut-Off Valve Testing
Ensuring all plumbing shut-off valves function properly in the event of leaks or system failures.
Drain, Vent & Pipe System Assessment
A full review of your home’s plumbing infrastructure — drains, vents, supply lines, and connections — to ensure proper flow and system health.
Code Compliance Review
We verify that your plumbing system meets all Long Island, Nassau, and Suffolk County regulations — essential for renovations, additions, or property sales.
Trusted Plumbing Expertise for Long Island Homes & Businesses
Our Plumbing Safety & Inspection Services Include:
NJM provides advanced inspection, leak detection, and safety evaluations to keep your plumbing system running efficiently, safely, and fully compliant with local codes.
Find HVAC Services Near You!
Service Area Links:
- Long Island
- Nassau County
- Suffolk County
What Our Long Island Clients Are Saying...
Kris
I couldn’t recommend Neil enough! From start to finish him and his team were professional, efficient and experienced. We had a job pulling up rocks and putting top soil down which I know can be a tedious job. We appreciate the work and look
Evelyn Powers
We had an ongoing issue with clogs. My daughter woke up to flooding in her bedroom from her toilet, which was not fun! This was our first time having NJM in our home. Neil was knowledgeable and gave us several options. we chose to have him use the camera to get to the root of the problem. He was able to pinpoint several issues and was able to fix clog and clean out the pipes. Neil and his crew were very professional,
Irene Cheung
I contacted NJM Mechanical because I didn’t have hot water anywhere in my house. Neil was able to diagnose the issue and get to work. My navien tankless water heater is only a year old and still under warranty. Instead of waiting on Navien to send the part so the issue can be corrected, Neil went out, found the part, purchased it,
William Lo
Great experience. Neil came out and took the time to explain everything thoroughly. He was able to fix all the errors on our Navien and have it back up and running. Following up a week later. Neil and Mike came out to redo the Navien system for proper instillation.
Unfortunatley, after there was a gas leak with our Navien system. Neil was able to get
James Farnworth
Neil from NJM was able to get my ac system up and running when others could not. He was honest with me right from the beginning and all costs were discussed before repairs began. Additionally, Neil spent time explaining to me how my system operates and the things I could do to help it run at peak performance. It was quite refreshing to experience a service technician who demonstrated the uppermost
Raul Chardon
Honest professional full of knowledge not BS. Takes pride in his craft and is a master of it.