Residential heating & air conditioning contractor in Merrimack, NH
GSMS is proud to serve the residents of Merrimack, NH, with top-quality heating and air conditioning services. As a family-owned business with over three decades of experience, we are dedicated to providing reliable, efficient, and professional HVAC solutions tailored to your home’s specific needs.
GSMS is proud to be your Merrimack Lennox Premier Dealer!
Whether it's an emergency repair, a total replacement, or routine maintenance, we have you covered. Call 603-424-8258 today!
Air conditioner repair & replacement
- AC Repair: We handle cooling problems big and small with speed and attention to detail. Our technicians are trained to troubleshoot and fix refrigerant leaks, thermostat issues, electrical failures, compressor problems, and more.
- AC Replacement and New Installation: Time for a cooling upgrade? We offer high-quality systems from Lennox and other leading manufacturers to improve efficiency, enhance comfort, and reduce homeowners' carbon footprint.
Furnace repair & replacement
- Furnace Repair: Dealing with a broken furnace? GSMS technicians work efficiently to track down even the smallest of problems and repair them in no time. Common furnace issues we repair include pilot light problems, thermostat malfunctions, ignition system failures, and blower motor problems.
- Furnace Replacement and New Installation: Upgrading your furnace takes your home's winter warmth to the next level. Our energy-efficient systems provide consistent heating, reduced maintenance, and enhanced safety.
Boiler repair & replacement
- Boiler Repair: Common boiler problems with pressure, thermostats, pilot lights, and leaks, can be a homeowner's nightmare. GSMS technicians work quickly to repair your boiler and get your home warm again in no time.
- Boiler Replacement and New Installation: Whether you are considering switching to a boiler system or it's time to replace your existing system, GSMS is here to help you increase efficiency and reliability with advanced units.
Mini-split heat pumps
GSMS provides comprehensive services for mini-split heat pumps, including installation, maintenance, and repair. We specialize in Mitsubishi ductless units, known for their reliability and efficiency. Whether you’re looking to install a new system or need service for your existing mini-split heat pump, our technicians are here to ensure optimal performance and comfort in your home.
Ductwork cleaning & installation
- Duct Cleaning: Regular duct cleaning helps improve air quality, increase HVAC efficiency, extend system lifespan, and eliminate odors. We use an advanced Roto Brush system to reach every corner of the ductwork and keep your home clean and comfortable.
- Duct Installation: Proper ductwork installation is crucial for airflow, efficiency, comfort, and durability. Choosing GSMS to install your ductwork gives you peace of mind that your new air ducts are safe and secure.
Merrimack plumbing services
GSMS is proud to provide comprehensive plumbing services to homeowners in Merrimack, NH. Our experienced and professional team is dedicated to delivering reliable and efficient plumbing solutions tailored to your specific needs.
Quick plumbing repairs, complete installations, and preventative maintenance are what we do best. Call 603-424-8258 today!
Water heater plumbers
- Repair: Our skilled technicians can quickly diagnose and repair common water heater issues, including inconsistent temperature, leaks, and strange noises.
- Replacement: When it’s time to replace your old water heater, we offer professional installation of both traditional tank models and modern tankless systems.
- Maintenance: Regular maintenance is essential to keep your water heater running efficiently. Our comprehensive maintenance services include inspections, cleaning, and tune-ups.
- Tankless Water Heaters: Upgrade to a tankless water heater for endless hot water, improved energy efficiency, and space savings. We provide expert installation and maintenance for these advanced systems.
Kitchen plumber services
- Faucets: From repairing leaks to installing new faucets, we ensure your kitchen faucets are functioning perfectly.
- Sinks: We handle all sink-related services, including installation, repair, and replacement, to keep your kitchen fully operational.
- Garbage Disposals: Our team can install and repair garbage disposals, ensuring efficient waste management in your kitchen.
- Dishwashers: We provide installation and repair services for dishwashers, making sure they are properly connected and running smoothly.
- Water Lines: Whether you need new water lines installed or existing ones repaired, GSMS ensures a reliable water supply for your kitchen appliances.
Bathroom plumber services
- Toilets: From fixing leaks and unclogging blockages to installing new toilets, we provide comprehensive toilet services.
- Showers and Tubs: We offer repair, replacement, and installation services for showers and bathtubs to keep your bathroom comfortable and functional.
- Sinks and Vanity Plumbing: Our team can install and repair bathroom sinks and vanity plumbing, ensuring everything operates seamlessly.
- Pipe Repairs and Replacements: Whether it’s a minor leak or a major pipe replacement, GSMS provides expert pipe repair and replacement services to prevent water damage and maintain optimal plumbing performance.
Why choose GSMS in Merrimack?
- Proven Track Record: With a long-standing presence in Merrimack, NH, GSMS has earned the trust of countless homeowners. Our dedication to excellence and reliability has made us a preferred choice for HVAC and plumbing services in the community. We are proud of our reputation and continually strive to uphold the high standards that have set us apart.
- Local Expertise and Dedication: GSMS has been serving the Merrimack, NH community for over three decades, building a reputation for excellence and reliability. As a family-owned business, we are deeply committed to our local community and understand the unique needs of Merrimack homeowners. Our local expertise allows us to provide tailored solutions that keep your home comfortable and efficient year-round.
- Comprehensive Range of Services: From HVAC to plumbing, GSMS offers a full spectrum of services to meet all your home comfort needs. Our skilled technicians are trained in the latest technologies and techniques, ensuring top-quality service for every job. Whether you need a quick repair, a new installation, or regular maintenance, we have the expertise to get the job done right.
Become a GSMS Home Club member today
Join the GSMS Home Club and enjoy exclusive benefits designed to keep your home’s HVAC and plumbing systems in top condition. Membership perks include:
- Priority Service
- No Diagnostic Fees
- 10% Off Repairs
- Home ID and Smart Monitoring
- Monthly Credits Towards Major Purchases
- Regular Maintenance
- Labor Warranty Upgrades
Call today for great service in Merrimack.
Trust the experts at GSMS to provide reliable, efficient, and top-quality services tailored to your needs. Whether you need a quick repair, a new installation, or regular maintenance, our dedicated team is here to ensure your Merrimack home remains comfortable and functional year-round.
Call 603-424-8258 today or fill out our online contact form to book an appointment!
Recent Jobs and Reviews in Merrimack, NH
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.
Our Local Reviews by City
- Amherst, NH (10)
- Atkinson, NH (2)
- Auburn, NH (1)
- Barrington, NH (22)
- Bedford, NH (28)
- Candia, NH (2)
- Chester, NH (2)
- Concord, NH (7)
- Deerfield, NH (1)
- Derry, NH (2)
- Dover, NH (1)
- Durham, NH (2)
- Epping, NH (1)
- Gilford, NH (1)
- Gilmanton, NH (1)
- Goffstown, NH (8)
- Greenland, NH (2)
- Hampstead, NH (2)
- Henniker, NH (3)
- Hillsborough, NH (1)
- Hollis, NH (15)
- Hooksett, NH (14)
- Hudson, NH (7)
- Lee, NH (1)
- Litchfield, NH (3)
- Londonderry, NH (14)
- Manchester, NH (59)
- Merrimack, NH (49)
- Milford, NH (8)
- Moultonborough, NH (1)
- Nashua, NH (55)
- New Boston, NH (4)
- Newbury, NH (1)
- Newmarket, NH (2)
- Northfield, NH (1)
- Northwood, NH (1)
- Pembroke, NH (1)
- Raymond, NH (1)
- Rochester, NH (2)
- Salem, NH (4)
- Sandown, NH (2)
- Stratham, NH (6)
- Tilton, NH (1)
- Weare, NH (5)
- Windham, NH (7)
- York, ME (1)
Job Locations and Reviews
Replace indirect tank. Install over flow pan.
Found that the indirect water tank is starting to fail. Wrote up an estimate and the client approved.
Customer had no heat. Found blown 1 amp fuse in zone panel
Fix boiler issues (COVERED UNDER WARRANTY). Replace toilet fill valve.
Completed the Rinnai tankless water heater maintenance today. I ran cleaner through it for 40 minutes. Next I flushed 10 gallons of water through it. I cleaned the water inlet screen. I vacuumed out the inside of the unit and vacuumed the filter. I checked incoming gas pressure and that was according to manufacturer specifications. I also checked all the drains and fixtures and everything looked great!
Completed the Rheem tankless water heater maintenance today. I started off with running a cleaner through it for 40 minutes. Next I flushed 10 gallons of water through it. I cleaned the water inlet screen. I checked incoming gas pressure and that was according to manufacturer specifications. The clients weren't sure if the water filter has ever been changed so I wrote up an estimate to replace the filter and the O-ring. I also inspected all of the drains and fixtures and everything looked great. We will order those parts today and reach out to you when they come in.
Completed the Rinnai tankless water heater maintenance today. I started off with flushing a cleaner through it for 40 minutes. After that I ran 10 gallons of water through it. I cleaned the water inlet screen. I vacuumed out the inside of the unit and the air filter. I checked incoming gas pressure and that was according to manufacture specifications. I also cleared the code 55 which is a service reminder. Next I completed the Veseman boiler maintenance. I cleaned the inside of the heat exchanger which was extremely dirty. I cleaned the flame sensor and electrode assembly. I cleaned out the trap and primed it. Lastly I ran the boiler on low and high fire and performed a combustion analyzer test that checks the units CO, CO2 and oxygen levels. The boiler was running great. I let the clients know about home club as well.
GSMS HomeClub plumbing maintenance.
Quentin arrived in time, was courteous and professional and answered all my questions.
I replaced the faulty flow check today. I insured there was no leaks. I ran the system and made sure the return came back hot.
I replaced the three-way valve today. After installing it I turned on both heating zones and made sure the returns came back hot. I had the client turn on the hot water and there is no loud clunking anymore when the three-way valve engages.
GSMS HomeClub PLUMBING VISIT.
Excellent!!!
Client was complaining of clogged toilet. I arrived client was snaking drain. I observed and took note of plumbing. Last couple years client has had issues. Plumbing pipes need to be pitched more for better flow. Advised client of how to resolve issue. Plumbing was not clogged when I was there.
Customer called and complained of fuel smell and haze in house. Smoke and carbon monoxide detectors did not detect anything. Ran burner and did tests,numbers and smoke levelsand draft matched previous numbers. Took apart smoke pipe. No signs of soot in boiler or smoke pipe. Noticed pieces of chimney tile in flue,mentioned to homeowner to get chimney inspected. I believe that she must of had a downdraft that brought in smell and haze.
Jack did a super job! Very thorough and competent. I feel like I’m in good hands with GSMS.
I diagnosed a bad flow check valve as the issue with upstairs over heating.
Replace thermostat with more basic option.
Replaced pressure switch ,will stop back after my next call to check thermostat differential
3 filters
The last snowstorm pushed snow through the exhaust vent and froze up inside of the unit. Pulled the inducer off and there was water and ice inside of it. Put it back together and ran the unit and everything was working great.
Replaced boiler burner door gasket and electrodes block. Completed the house plumbing inspection. I checked the fixtures and drains and everything looked good. The only thing that I noticed was that the expansion tank coming off of the indirect tank has failed. I will send you over an estimate to replace the tank.
Check all controls we think it could be gas valve and pressure switch
Jack from GSMS came today and serviced our tankless hot water heater. Excellent job as always
Installed the new hot surface igniter for the Lennox furnace. I completed the plumbing maintenance today. I inspected all the fixtures and the drains and everything looked great. I labeled some emergency shut off tags. I drained down the Rheem tanked water heater. I didn't pull the anode rod because the water heater is only 4 months old. I made sure to turn the water heater back on and I let the client know that it would be hot again within an hour. Lastly I removed the kitchen sink aerator and made sure there was no air in the hot water pipes.
Perform maintenance on propane Viessmann boiler. Please see maintenance form for details of today's service. Thank you!
Arrived on time, organized equipment. Friendly, answered all my “many questions”. Adam made sure all the equipment was in working order. Excellent service.
Intermittent problem with furnace. Checked in incoming gas pressure at 5.9 inches, manifold pressure was 3.5 inches. Check the pressure switch rollout switch. Look for loose wire connections check air filter. Check condensate tube turn furnace on and off multiple times was not able to replicate problem.
No heat. Oil pressure no spark. Went through wires on primary checked connections. Put back together,
Always amazing service, every team member at GSMS has always been great and performed exceptionally great service.
Jack was once again on time, diagnosed the problem quickly and fixed it. All GSMS staff are courteous and extremely professional. I wouldn’t go with anyone else.
The experience started with Gina in the office who was very responsive and accommodating and made the scheduling process super efficient and friendly. Then Mark came and brought his expertise to my home and systems to point areas of installation failures by the company that installed my system. Just using the basic manual to point out how they cut corners. Mark spent the time to correct the exhaust piping to fix leaks and improve air flow. He was friendly and accommodating.
Very happy with the job done.
Quick service call to replace thermostat. Done in about 15 minutes, explained the workings. Very satisfied Great service as usual
Jack was polite and very neat.
We have been working with GSMS for 8 years. They provide the best service for installs and maintenance. The people are very professional, friendly and do great work. Today Qwentin was the tech doing the service maintenance. This young man came at the time scheduled, knew what he was doing and did excellent work. If you are in need for heating, air conditioning and plumbing work, this is the company for you!
Jack did a great job. Provided a lot of good information. Thank you
Excellent service
Excellent Service
Excellent
Quentin was awesome he was very professional, respectful and extremely knowledgeable and competent. Great personality. and exhibited interpersonal and communication skills.
Never problem with GSMS! They have installed and serviced my furnace and AC for 27 years. Over the years Mark has gone out of his way to fix problems and now crew is continuing his great service! I have recommended them to many people.
Very good experience - good communication from Gina about scheduling. Techs (Jack and Qwentin) showed up on time and completed the job (new hot water heater and related cleanup) efficiently.
Qwentin is a valued team member of GSMS (Granite State Mechanical Services). He is friendly and knowledgeable
Qwentin was on time and provided excellent service as always
Excellent in all areas of service. Punctual, courteous, kept us well informed of service progress. Upon completion of the furnace installation Adam explained all features of the new system , and addressed questions . The above statement can be said of all GSMS employees as we have used them over the years for several different systems installation. Excellent in all areas.
Excellent service
Friendly and knowledgeable
Everything is working great!
