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
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
Undersink water heater leaking caused by supply hose. I replaced both hot and cold hose. The leak is now gone.
I ran almost 2 gallons of water through Ductless system in XRAY. Everything was working properly related to the drain. I could not find a source of a water leak related to the system.
Prompt and attentive young man. Excellent job
Replace two outdoor faucets. New spigots will be frost free. Cutout mess of fittings and tee in boiler room as discussed with David.
Completed the AC maintenance today. Everything was working great. Please see the attached form.
Completed the AC maintenance today. Everything looks great! Please see the attached form.
Gsms homeclub ac maint.
Completed the AC maintenance today. Everything went great. Please see the attached form.
Completed the AC maintenance over here. Everything went great. Please see the attached form. The office will be reaching out with scheduling the water heater replacement. We will bring the replacement air filter as well
This proposal outlines the installation of a premium 5-Zone Mitsubishi heat pump system. To honor your request of having only one outdoor unit while properly serving all three levels of the home (basement, first floor, and second floor), we have upgraded the design to utilize Mitsubishi’s advanced Smart Multi system. This commercial-grade technology uses a centralized "Branch Box" distribution method, allowing us to run the extended refrigerant line lengths required for this specific floor plan while strictly adhering to manufacturer engineering specifications. Scope of Work 1. Outdoor Equipment & Distribution Condenser Placement: Supply and install one (1) Mitsubishi Smart Multi outdoor heat pump condenser. The unit will be located on the gable end of the home (garage side), neatly tucked into the corner where the chimney jogs out. Attic Branch Box: Install the required Mitsubishi Branch Box up in the attic space. The main refrigerant trunk line will route from the outdoor unit up
As always, Excellent work!
Jack is a nice guy. Explains things well. Respectful of my home. Thorough
Arrived on time, was meticulous in his work and answered all my questions, even the ones not related to my service.
Excellent service
He arrived on time and was neat and orderly and very pleasant to deal with.
Respectful and knows what he is talking about. Even dealt with Stanley in a way they are always welcome back. If i could give more than 5 stars i would.
Very pleased with Qwentin
Qwentin was on-time. Friendly, polite, and conscientious. All work was performed and verified. Would recommend to anyone looking for HVAC service or installation.
Great service, nice app to track when service tech will arrive. Answered all questions pleasant to talk with and very conscientious.
Love dealing with this company. Their techs are always prompt, efficient and courteous. We've been happy to be their customer since 2010.
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
Qwentin was on time, very friendly and professional. He was able to identify the issue, communicate it effectively, and then fix it. Highly recommend.
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
Great service again. On time and professional. I highly recommend GSMS.
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
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
top notch service, always professional. would recommend to anyone needing HVAC service, repair or install.
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!
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
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!
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.
We thank you for sharing your positive experience. It made our day.
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