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Our Service Area

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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 388 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

Review
Excellent and very prompt.. Thank you
Mike - Hampton, NH 03842
Jack D.
Jack D. Checked in
The display for the MHK2 controller said "REPLACE ME". Homans tech support confirmed that the display needed to be replaced due to a failed sensor or other reason. I replaced with a new MHK2 and everything is operating correctly now.
Hampton, NH 03842
Review
Great service
Mark - Barrington, NH 03825
Qwentin G.
Qwentin G. Checked in
Completed the mini split maintenance today. Everything went great. Please see the attached form.
Concord, NH 03301
Jack D.
Jack D. Checked in
Minisplit preventative maintenance.
Barrington, NH 03825
Mark D.
Mark D. Checked in
Remove second d floor toilet and replace was gasket and closet bolts.Replace 22' of 1/2" l copper pipe and installed new valve.
Manchester, NH 03104
Qwentin G.
Qwentin G. Checked in
Completed the AC maintenance today. Everything went great! Please see attached form.
Bow, NH 03304
Jack D.
Jack D. Checked in
AC maintenance. Please see the form for details of todays servicing. Thank you!
Barrington, NH 03825
Jack D.
Jack D. Checked in
Bad control board. We will be back tomorrow
Milford, NH 03055
This is our highly recommended design utilizing premium Mitsubishi equipment. It utilizes the exact same second-floor layout and standard heat pump capabilities as Design 1, but upgrades the third-floor unit to a low-profile Floor-Mounted Console. Given the specific dimensions and ceiling angles of your third floor, this option provides the absolute cleanest aesthetic and optimal airflow. Scope of Work 1. Indoor Equipment (Third Floor - Floor Mount) Third Floor Space: Install one (1) Mitsubishi Floor-Mounted ductless console. Layout Adjustment: As we discussed during our consultation, utilizing this floor-mounted unit will require a minor rearrangement of the craft table furniture, but it guarantees the most unobtrusive and visually pleasing installation for this unique space. The exterior lines will drop down to meet the second-floor lines in a "T" and run horizontally along the roofline. 2. Indoor Equipment (Second Floor) Back Guest Bedroom: Install one (1) Mitsubishi wall-moun
This is our highly recommended design utilizing premium Mitsubishi equipment. It utilizes the exact same second-floor layout and standard heat pump capabilities as Design 1, but upgrades the third-floor unit to a low-profile Floor-Mounted Console. Given the specific dimensions and ceiling angles of your third floor, this option provides the absolute cleanest aesthetic and optimal airflow. Scope of Work 1. Indoor Equipment (Third Floor - Floor Mount) Third Floor Space: Install one (1) Mitsubishi Floor-Mounted ductless console. Layout Adjustment: As we discussed during our consultation, utilizing this floor-mounted unit will require a minor rearrangement of the craft table furniture, but it guarantees the most unobtrusive and visually pleasing installation for this unique space. The exterior lines will drop down to meet the second-floor lines in a "T" and run horizontally along the roofline. 2. Indoor Equipment (Second Floor) Back Guest Bedroom: Install one (1) Mitsubishi wall-moun
Adam P.
Adam P. Checked in
This is our highly recommended design utilizing premium Mitsubishi equipment. It utilizes the exact same second-floor layout and standard heat pump capabilities as Design 1, but upgrades the third-floor unit to a low-profile Floor-Mounted Console. Given the specific dimensions and ceiling angles of your third floor, this option provides the absolute cleanest aesthetic and optimal airflow. Scope of Work 1. Indoor Equipment (Third Floor - Floor Mount) Third Floor Space: Install one (1) Mitsubishi Floor-Mounted ductless console. Layout Adjustment: As we discussed during our consultation, utilizing this floor-mounted unit will require a minor rearrangement of the craft table furniture, but it guarantees the most unobtrusive and visually pleasing installation for this unique space. The exterior lines will drop down to meet the second-floor lines in a "T" and run horizontally along the roofline. 2. Indoor Equipment (Second Floor) Back Guest Bedroom: Install one (1) Mitsubishi wall-moun
Lee, NH 03861
Qwentin G.
Qwentin G. Checked in
Completed the AC maintenance today. I started off with washing the outdoor units coil with coil cleaner and water. I checked all the electrical connections and the capacitor and everything looked good. Next I went inside and I checked the air filter, that was clean. I checked the blower motor capacitor and electrical connections and everything looked good. I brushed and flushed the condensate trap with cleaner. Lastly I ran the unit in cooling mode. I connected my gauges and all my readings were coming back great.
Merrimack, NH 03054
Jack D.
Jack D. Checked in
Maintenance on 3 central air split systems & 2 HRV'S. Replace 3 air filters. I found 2 capacitors that need to be replaced.
Manchester, NH 03102
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
.
Zsolt - Nashua, NH 03062
Review
Seems like a thorough inspection and update....great job Qwentin.
Phil - Windham, NH 03087
Review
The service was really good. He did great work.
Ann - Derry, NH 03038
Review
Always GREAT service
37 - Manchester, NH 03103
Review
Qwentin did a great job. Highly recommend him.
Gary - Stratham, NH 03885
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 water heater service. On time and professional l He gave me some helpful tips on other water related issues. 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.

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