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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 406 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

Jack D.
Jack D. Checked in
Replace existing failed water heater with a new direct replacement model. Will include bringing up to code with a new expansion tank bracket.
Hampton, NH 03842
Qwentin G.
Qwentin G. Checked in
Completed the AC maintenance today. The unit is a little low on refrigerant. Previously someone put a UV dye in the system. I recommended seeing how the unit performs when it gets a little warmer out and then we can go from there with repairing or replacing the system.
Goffstown, NH 03045
Adam P.
Adam P. Checked in
Thank you for having me out to evaluate your home's comfort issues! Based on my load calculation, your first-floor cooling issues are stemming from the original installation. The previous contractor attempted to cool both the living room and the kitchen by placing one oversized 15,000 BTU unit in the living room. Because that unit is so large for the space it's actually in, it cools the room too quickly and shuts off before it can pull the humidity out of the air—leaving your living room feeling "cold and clammy" while the kitchen stays hot. The Solution: We are going to add a dedicated, perfectly sized single-zone Mitsubishi mini-split directly into the kitchen where the heat is trapped. By running this new kitchen unit continuously, it will act as the "heavy lifter," efficiently cooling the space and pulling the trapped humidity out of the entire first floor. This will allow you to raise the temperature on your oversized living room unit so it stops short-cycling, finally balancing
Barrington, NH 03825
Qwentin G.
Qwentin G. Checked in
Completed the AC maintenance today. Everything looks great. Please see the attached form.
Nashua, NH 03064
Qwentin G.
Qwentin G. Checked in
Completed both of the AC maintenances today. Everything went great! Please see the attached form.
Hollis, NH 03049
Jack D.
Jack D. Checked in
GSMS HOMECLUB AC VISIT.
Manchester, NH 03104
Review
Friendly, thorough and efficient!
Bob - Sandown, NH 03873
Review
Qwentin was super communicative about what the AC service check entailed - accommodating/ polite/professional. Thank you Qwentin!
Susan - Hooksett, NH 03106
Jack D.
Jack D. Checked in
Go over auto changeover on thermostat. Would like to see other options for thermostat. We will send over an estimate.
Manchester, NH 03102
Review
Customer service great, technician knowledgeable & explained what was going on.
Michelle - Manchester, NH 03104
Review
Very good.
Phil - Hooksett, NH 03106
Jack D.
Jack D. Checked in
Furnace PM and wash condenser coil. The vent near the furnace needs fittings to be replaced. The customer said that they will replace them.
Hooksett, NH 03106
Qwentin G.
Qwentin G. Checked in
Completed the AC maintenance today. Everything looks good. Please see the attached form.
Manchester, NH 03104
Qwentin G.
Qwentin G. Checked in
Completed the AC maintenance today. Everything looks great for the age! Please see the attached form.
Hooksett, NH 03106
Review
I’ve used GSMS for years now. They have always provided top notch services and workmanship. Shout out to Jack specifically for today help 🙌🏻
Sam - Concord, NH 03301
Review
Prompt and attentive young man. Excellent job
Sandra - Bedford, NH 03110
Review
As always, Excellent work!
Jenn - Hudson, NH 03051
Review
Jack is a nice guy. Explains things well. Respectful of my home. Thorough
Georgia - Epping, NH 03042
Review
Arrived on time, was meticulous in his work and answered all my questions, even the ones not related to my service.
Terry - Manchester, NH 03109
Review
Excellent service
Lisa - Exeter, NH 03833
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