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Our Service Area

Proudly Serving New Hampshire Homeowners

At GSMS, we are proud to serve New Hampshire with our comprehensive range of HVAC and plumbing services.

As a family-owned business with 35+ years of experience, we have built a reputation for excellence, reliability, and outstanding customer care. Our skilled technicians are dedicated to providing top-quality repairs, installations, and maintenance tailored to meet the unique needs of New Hampshire homeowners.

Explore our service area below, read reviews in your city, and see why homeowners across New Hampshire trust GSMS for their HVAC and plumbing needs.

Contact us online today or call 603-424-8258 to schedule your service and experience the GSMS difference.

Recent Jobs and Reviews

Rated 5.0 out of 5 stars based on 393 customer reviews

Customers say: The recent reviews exhibit a predominantly positive sentiment, with recurring themes of satisfaction, professionalism, and expertise. Customers express gratitude, recommend the company, and acknowledge the quality of the work performed. Positive reviews frequently mention friendly and knowledgeable technicians, timely responses, and efficient service. Negative reviews are minimal and do not represent a clear, recurring trend. Overall, the reviews suggest a positive experience with the company, with many customers expressing satisfaction with their HVAC and plumbing needs.

Job Locations and Reviews

Manchester, NH - Installed a new 40 gallon atmospheric natural gas water heater
Adam P.
Adam P. Checked in
Installed a new 40 gallon atmospheric natural gas water heater
Manchester, NH 03109
Qwentin G.
Qwentin G. Checked in
Completed the first AC start up. All my pressures and temperatures looked great. It is ready to start cooling this summer!
Bow, NH 03304
Jack D.
Jack D. Checked in
New AC startup. Everything is running fantastic. Thanks again!
Nashua, NH 03064
Review
Qwentin was on-time. Friendly, polite, and conscientious. All work was performed and verified. Would recommend to anyone looking for HVAC service or installation.
Thomas - Merrimack, NH 03054
Qwentin G.
Qwentin G. Checked in
Completed the AC maintenance today. Everything went great! Please see the attached form.
Merrimack, NH 03054
Jack D.
Jack D. Checked in
Mitsubishi Ductless maintenance and central air maintenance. All set. Thank you! Replaced air filter for furnace system.
Salem, NH 03079
Review
Great service, nice app to track when service tech will arrive. Answered all questions pleasant to talk with and very conscientious.
John L - Bedford, NH 03110
Qwentin G.
Qwentin G. Checked in
Completed the AC maintenance today. Everything went great. Please see the attached form.
Bedford, NH 03110
Jack D.
Jack D. Checked in
Today I replaced 2 outdoor water spigots with new frost free versions. I reccomend a water test due to the old hoses being stuck on and the appearance of a lot of the fittings in the basement. I reccomend replacing irrigation valve and the hose/ drain valve below it.
Londonderry, NH 03053
Review
Qwentin was his professional and friendly self today. I am always very happy with his work.
Barry Fitzgerald - Manchester, NH 03109
Jack D.
Jack D. Checked in
GSMS HomeClub AC visit. All 3 systems serviced. I only had to replace the filter for upstairs Mitsubishi system. The furnace had a spare filter by the side that I replaced. Thank you!
Londonderry, NH 03053
Qwentin G.
Qwentin G. Checked in
Completed the AC maintenance today. Everything went great. Please see the attached form.
Manchester, NH 03109
Completed the AC maintenance, furnace maintenance and the tankless water heater maintenance. Everything went great today! Please see the maintenance forms that are attached to the email.
Completed the AC maintenance, furnace maintenance and the tankless water heater maintenance. Everything went great today! Please see the maintenance forms that are attached to the email.
Qwentin G.
Qwentin G. Checked in
Completed the AC maintenance, furnace maintenance and the tankless water heater maintenance. Everything went great today! Please see the maintenance forms that are attached to the email.
Exeter, NH 03833
Review
Glad to see the ole man still working!! LOL
Phil - Windham, NH 03087
Review
Friendly, efficient service
Charlie - Concord, NH 03301
Review
Excellent and very prompt.. Thank you
Mike - Hampton, NH 03842
Review
Great service
Mark - Barrington, NH 03825
Review
Jack did an excellent job cleaning and servicing our mini-split. He is amiable, efficient, and professional. It was a great experience!!!
Kathleen - Nashua, NH 03062
Review
good service
Peter - Merrimack, NH 03054
Review
The best
James - Manchester, NH 03104
Review
Love dealing with this company. Their techs are always prompt, efficient and courteous. We've been happy to be their customer since 2010.
Skip Sagris - Bow, NH 03304
Response from GSMS Air•Heating•Plumbing:

Thank you so much for the kind words and for being part of the GSMS family since 2010! It means the world to us to have earned your trust over the years. I’m proud of our team for continuing to deliver the kind of service that keeps clients like you coming back. We truly appreciate your loyalty and support. – Zak D., Second-Generation Owner

Review
Qwentin was on time, very friendly and professional. He was able to identify the issue, communicate it effectively, and then fix it. Highly recommend.
Phil Cutler - Bedford, NH 03110
Response from GSMS Air•Heating•Plumbing:

Thank you so much for the kind words and for trusting GSMS to take care of your home. Qwentin is a rising star on our team, and it means a lot to hear that his professionalism and communication made a strong impression. As a local, family-run business, we’re grateful for your recommendation and honored to have earned your trust. – Zak D., Second-Generation Owner

Review
Great service again. On time and professional. I highly recommend GSMS.
Katherine Turner - Exeter, NH 03833
Response from GSMS Air•Heating•Plumbing:

Thank you for the great review! I’m glad to hear our Specialist was able to get your water heater squared away and offer some extra tips while he was there. We always aim to go beyond just the repair, and I really appreciate you taking the time to share your experience. Thanks for choosing GSMS — it means a lot to our family and our team. – Zak D., Second-Generation Owner

Review
David DiNardo - Bedford, NH 03110
Response from GSMS Air•Heating•Plumbing:

Thank you for the 5 stars, David! We really appreciate you choosing GSMS and supporting our family-run team. If there’s ever anything more we can do for you, don’t hesitate to reach out. – Zak D., Second-Generation Owner

Review
claire lafond - Merrimack, NH 03054
Response from GSMS Air•Heating•Plumbing:

Thank you so much for the 5 stars, Claire! We’re grateful for your support and truly appreciate you choosing GSMS. It means a lot to our family and our entire team. – Zak D., Second-Generation Owner

Review
Great work, fair prices.
Tom Grasse - Manchester, NH 03104
Response from GSMS Air•Heating•Plumbing:

We thank you for sharing your positive experience. It made our day.

Review
top notch service, always professional. would recommend to anyone needing HVAC service, repair or install.
Ben Bouchard - Nashua, NH 03062
Response from GSMS Air•Heating•Plumbing:

It was a pleasure serving you and your family. Thank you for sharing your kind words with us. It means the world to us and to our entire team!

Review
Had an issue with our heat pump. Reached out for assistance and they had someone on site that afternoon. Problem was resolved quickly. Super friendly service. The tech was exceptionally friendly and an excellent communicator. Highly recommend
Mark Cooke - Greenland, NH 03840
Response from GSMS Air•Heating•Plumbing:

It was a pleasure serving you and your family. Thank you for sharing your kind words with us. It means the world to us and to our entire team!

Review
I needed to have shut off valves under my kitchen sink and a new hose attachment on my sprayer since the cheap plastic tubing was cracked. Mark was punctual, professional and extremely knowledgeable regarding the job. I am always impressed with GSM and how they run their family business. Mark completed the job quickly and efficiently. I can trust GSM and will continue to seek their help in the help in the future. GSM has installed a mini split, oil boiler, hot water heater in my home and I would highly recommend them to family and friends.
Kimberly Cichon - Newmarket, NH 03857
Response from GSMS Air•Heating•Plumbing:

We thank you for sharing your positive experience. It made our day.

Review
As usual, Jack's work is stellar.
Bob Bedrosian - Merrimack, NH 03054
Response from GSMS Air•Heating•Plumbing:

We are so glad to hear that you had a good experience.

Trusted Quality & Service