If you hire this pro, you’re covered by a money-back guarantee. Learn more
If you hire this pro, you’re covered by a money-back guarantee. Learn more
About
I'm a Master Plumber. I provide Quality and Perfection. That is my number one goal. I do the job correctly and professionally. I'm not the cheapest, but I am skilled at what I do.
Notes : We charge a $100 service fee, but if GNK Plumbing is hired for the job the fee will be waived.
Monday to Saturday from 8.00 Am to 6.00 Pm
Overview
Current Top Pro
Hired 328 times
Serves Methuen, MA
Background checked
License verified
2 employees
21 years in business
Business hours
This pro hasn't listed their business hours.
Payment methods
This pro accepts payments via Cash, Check, and Credit card.
Top Pro status
Top Pros are among the highest-rated, most popular professionals on Thumbtack.
2025
2024
2023
Credentials
License verified
Plumber – Master
License state: MA
Background checked
Passed by Jean Kossaifi on Jan 4, 2023.
Services offered
Project type
Pipe material
Copper
Iron
Steel
PVC or CPVC
Appliances to hook-up
Stove or oven
Outdoor BBQ or grill
Water heater or boiler
Dryer
Projects and media
Projects and media
Reviews
Customers rated this pro highly for professionalism, work quality, and responsiveness.
Excellent 4.9
217 reviews
5
96%
4
1%
3
1%
2
1%
1
1%
Your trust means everything to us. Learn about our review guidelines.
Read reviews that mention:
James D.
Apr 25, 2026
•
Hired on Thumbtack
Jean was at my house within 30 minutes and took care of my job for a great value. He was very honest and sincere about our heating system and how to properly maintain it. We will definitely use GNK for all of our plumbing needs in the future. I already recommended him to my neighbors. Thanks again for your help Jean!
Details: No, repair is not urgent • No, the building is not currently flooded • Part of a larger issue with the plumbing system • House
Plumbing Pipe Repair
Ria R.
Feb 5, 2026
•
Hired on Thumbtack
Jean was efficient and did an excellent job fixing our heating system. Will continue to use his company for any future heating projects. Thanks Jean!
Details: Boiler • Not enough heat • Two-story building • House
Heating System Repair or Maintenance
Maria V.
Apr 13, 2026
•
Hired on Thumbtack
Jean came out in 20 min, quoted a very fair price and completed the work super fast. Would recommend his services anytime and will likely be calling him back for more plumbing projects soon. Thanks!
Details: No, repair is not urgent • No, the building is not currently flooded • Other pipe issue • Sink • House
Plumbing Pipe Repair
Milagros H.
Oct 29, 2025
•
Hired on Thumbtack
We recently had an issue with the heating system at one of our rental properties — the tenant was left without heat. GNK responded quickly and handled the situation with professionalism from start to finish. They arrived promptly, diagnosed the problem efficiently, and made the necessary repairs the same day.
The tenant now has full heat restored, and they were very pleased with how courteous and respectful the plumber was throughout the visit. Communication was clear, the work was completed neatly, and the overall service was excellent.
Highly recommend GNK for anyone in need of reliable, skilled plumbing or heating repair service.
Details: Boiler • No heat • Two-story building • Condo or apartment
Heating System Repair or Maintenance
John S.
Feb 26, 2026
•
Hired on Thumbtack
Jean was extremely responsive! He kept out appointment the morning after the blizzard. we made a slight adjustment with the appointment time due to the snow. He actually arrived a half hour before the agreed upon time.
Once he diagnosed the situation, he proceeded to fix it.
He explained what the issue was and what he did to fixbit.
I would highly recommend Jean!!
Details: No, repair is not urgent • Only one drain has issues • Leaking (problem area known) • House
Plumbing Drain Repair
FAQs
What should the customer know about your pricing (e.g., discounts, fees)?
I offer multiple options with different proces and offer discounts depending on the job
What is your typical process for working with a new customer?
meet to customer assess the issue and discuss the options for the solution and make sure the customer is comfortable with our work
What education and/or training do you have that relates to your work?
I completed my journey license and master license. I have attended trainings around boilers and I complete yearly trainings to stay up to date with the latest procedures
