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 overall sentiment across these reviews is overwhelmingly positive, reflecting high levels of customer satisfaction and appreciation. Customers consistently express enthusiasm about the quality of service they received, with recurring praise for professionalism, expertise, and efficiency. A dominant theme throughout is the technical skill and knowledge demonstrated by the service team, with many reviewers highlighting how thoroughly problems were diagnosed and resolved. The interpersonal qualities of the technicians emerge as another strong positive trend, with customers frequently describing them as friendly, personable, pleasant, and respectful. Communication stands out as a particularly valued aspect, with reviewers appreciating clear explanations, patience in answering questions, and being kept informed throughout the service process. Timeliness and punctuality are consistently mentioned as strengths, alongside respect for customers' property and maintaining clean, orderly work practices. Many customers express strong loyalty and trust in the company, with several indicating they are repeat customers or plan to continue using the service. The tone is enthusiastic and grateful, with multiple reviewers offering strong recommendations and expressing genuine happiness with the results. Overall, these reviews paint a picture of a service provider that excels in both technical competence and customer care, creating consistently positive experiences that foster long-term customer relationships.
Job Locations and Reviews
Well Water test Comprehensive + radon.
Completed the AC maintenance and the furnace maintenance today. Everything went great! Please see the attached maintenance forms. I will send over the estimate for the hot water heater repairs.
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This proposal outlines the replacement of your failed 40-gallon Bradford White power-vented natural gas water heater. Because your tank is currently covered under the manufacturer's warranty, the physical cost of the new tank itself is covered. The pricing in this proposal strictly covers the professional labor, the distributor's warranty processing fee, the necessary structural plumbing modifications, and the required safety code upgrades to properly install the new unit. Scope of Work 1. Demolition & Warranty Processing Removal: We will safely drain, disconnect, and remove your existing failed water heater. Warranty Handling: GSMS will handle the logistics of returning the failed tank and will cover the $100 warranty processing fee charged by the distributor on your behalf. 2. Equipment Installation & Code Upgrades The New Tank: We will supply and install your new warranty-replacement 40-gallon Bradford White power-vented natural gas water heater in the exact same footprint. Conn
Removed the dip tube and the anode rod. Cleaned the threads on the tank really well. Taped and used pipe sealant on the threads. I let the client know that the wet sensor got a little bit of water on it so I left it unplugged so it can dry out.
Completed the Central AC maintenance and the mini split maintenance. Everything went great! I found inside of the furnace two gas leaks and a gas leak below the shut-off for the furnace. After repairing the leaks I gas sniffed all lines with my electronic sniffer and everything was good. No more leaks. Please see the attached form as well.
very courteous, efficient. a pleasure to work with.
Installed new thermostat. Tested operation and everything was working as it should.
This proposal outlines the rapid replacement of your existing, failed Fujitsu multi-zone system. Because your current system has suffered a refrigerant leak, we will completely remove the old equipment and replace it with a highly reliable Mitsubishi 2-zone ductless system. Based on our load calculations, your current capacities are perfectly sized for the spaces. We will be installing a standard Mitsubishi heat pump (non-Hyper Heat), which acts as a direct equivalent to your previous system. This will provide you with excellent, reliable air conditioning throughout the summer, as well as highly efficient supplemental heating during the milder spring and fall shoulder seasons. Scope of Work 1. Demolition & Equipment Removal Safe Extraction: We will safely recover any remaining refrigerant, disconnect the electrical components, and completely remove the existing Fujitsu outdoor condenser and the two indoor wall heads. 2. Indoor Equipment (2 Zones) We will supply and install two (2
CALL BACK IS IN THE WORKS- THERMOSTAT IS BLACK - NO REPSOPONSE.
Found overflow switch off.Looks like air was blowing on it from door cover moved switch .
Removing vent and relocate drain line under sink and install atm vent.We will do temperaily cap on roof flange.Home owner to do have roofer do permanent patch.Will cut vent pipe and leave inside wall unless owner has sheetrock removed than we can remove pipe.
First time using this company, and I was very impressed with the service as well as the knowledge of the Technician
Excellent as usual
Great service, right on time. Jack did a great job picking out my new faucets.
Qwentin was right on time and provided friendly and thorough service for my boiler. He answered all of my questions and the pricing felt very fair. Thanks!
Arrived quickly to my situation and solved the problem immediately
Excellent service, hard working individual, arrived on time
Great job
Great team to work with very knowledgeable and easy-going
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!
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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