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Top-Rated Tankless water heater installers in West Islip - Updated Nov 2026

Avatar for AquaFlow Plumbing Heating & Water Systems
AquaFlow Plumbing Heating & Water Systems
5.0(
10
)
Tankless Water Heater - Install

Serving West Islip, NY and surrounding areas

Approved

In business since 2020

Free estimates

Small jobs welcome

"I moved into my new home on 7/8 and knew I needed to replace the 20 year old hot water heater. The water was warm in the shower and brown. Originally, I planned on getting a tankless unit, but that was prohibitively expensive and not allowed in my community. Taking the next prudent steps, I secured my three estimates. Not only was AquaFlow the least expensive, but when I met Enrique, I knew I wanted to work with him on this project and all future plumbing issues. He explained what needed to be done, secured the tank from the supply dealer, and showed up at 9:00 AM promptly as promised. It was originally planned to be a two man job, but the other person couldn’t make it. Enrique did the entire job on his own. I was amazed. He worked until 5:00 PM. I asked why he didn’t just reschedule with me, but he stuck to the date and time he gave me. He also installed my new touch-less faucet and adjusted the cartridge in the shower and I now can take hot (not warm) showers."
Project Photos
Projects done
Projects done
Projects done
Projects done

+5

2 neighbors recently requested a quote
Avatar for Mr. Big Plumbing & Heating
Mr. Big Plumbing & Heating
4.9(
15
)
Tankless Water Heater - Install

Serving West Islip, NY and surrounding areas

Approved

In business since 2022

Free estimates

Warranties offered

"They were friendly, experienced and attentive to our concerns. They also provided critical advise/information as to our overall plumbing needs including competitive cost estimates."
Response time1 day
Response rate90%
Recommended by100%of homeowners
Avatar for Varsity Home Service Company, Inc.
Varsity Home Service Company, Inc.
4.4(
244
)
Tankless Water Heater - Install

Serving West Islip, NY and surrounding areas

Approved

In business since 1962

Free estimates

Emergency services offered

"Although I didn’t hire Varsity for my Aircon installation, I had the pleasure of working with their top class representative, Erica Bellini. She is an amazingly responsive, smart and diligent person. If you are considering using this company, I highly recommend you ask for Erica."
Shower Fixtures
Installation
Truck
Best of L.I. Winner 2024
Angi 2022 Super Service Award Winner

+86

Response time11 hrs
122 neighbors recently requested a quote
Recommended by84%of homeowners
Avatar for Patience HVAC, LLC
Patience HVAC, LLC
4.9(
30
)
Tankless Water Heater - Install

Serving West Islip, NY and surrounding areas

Approved

In business since 2020

Free estimates

Emergency services offered

"I am very happy that I hired Patience HVAC to replace my hot water heater. I have an oil burner and oil hot water heater. The 18 year old heater was making crackling noises and I was advised by the oil company to replace it. I wanted to convert to a gas hot water heater and tried going through Lowes. However, they only do swap outs if the existing heater is already set up for gas. So I contacted several companies for a quote. Out of all of them, Anthony was the most professional, down to earth and reasonably priced. First, he suggested to explore correcting the issue on the old heater and save me money which was impressive. I decided to proceed with a new gas heater. The quote he gave me was $800 less than the next lowest quote. Anthony sent his workers Caesar and Matt the next day which I greatly appreciated. They were both very polite and wore covers on their shoes so to avoid dirtying my house more than necessary. Anthony came later in the day to ensure everything was done correctly. He then offered to call him with any questions even if they were not pertinent to the work they performed. I am extremely impressed with patience HVAC honesty, professionalism and reasonable prices. I will be sure to recommend them to friends and family. When I am ready to install a ductless air conditioner, I will definitely contact Patience HVAC."
Peerless
Peerless Boiler with Hot Water
Annual Service
Response time4 hrs
Recommended by100%of homeowners
Avatar for All Weather Heating & Cooling
All Weather Heating & Cooling
4.5(
70
)
Tankless Water Heater - Install

Serving West Islip, NY and surrounding areas

Approved

In business since 1969

Free estimates

Emergency services offered

"Tom was terrific....repaired boiler....cost reasonable.....explained everything so clearly so that even this 88year old understood it....experience with company from start to finish was a pleasure"
Additional Photos
Additional Photos
Additional Photos
Additional Photos
Additional Photos

+13

Response time3 days
7 neighbors recently requested a quote
Recommended by94%of homeowners
Avatar for BERARDI ELECTRICAL CONTRACTING, INC.
BERARDI ELECTRICAL CONTRACTING, INC.
3.7(
72
)
Tankless Water Heater - Install

Serving West Islip, NY and surrounding areas

Approved

In business since 1999

Free estimates

Emergency services offered

"We contacted Berardi Electricals through Angi, and Leo reached out to us right away.Leo came to our house within an hour, quickly identified the issue as water damage to the main electrical box, and explained that it was an emergency situation. He returned the following week, exactly as discussed, despite bad weather, and efficiently moved the box, repaired the wiring, and provided temporary electricity until the next day. His work was exceptionally clean, efficient, and thorough, and he took the time to give us the right advice, possibly saving us from an electrical fire. We found him to be honest, knowledgeable, and true to his word. We would highly recommend Berardi Electricals to anyone looking for a trustworthy electrical work."
Lido beach NY
Lido beach NY
Lido beach NY
Response time7 hrs
Response rate100%
4 neighbors recently requested a quote
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The West Islip, NY homeowners’ guide to tankless water heater installations

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