Your Trusted Heating, AC & Plumbing Experts in Londonderry, NH
Since 1987, GSMS has been proud to offer top-notch HVAC services to residents of Londonderry, NH. With over three decades of experience, our family-owned business has built a reputation for excellence, reliability, and outstanding customer service. We provide a comprehensive range of HVAC services, including air conditioning repair, replacement, and maintenance, as well as heating services for furnaces and boilers. Our expert technicians are also skilled in installing and maintaining ductless mini-split systems, ensuring that your home stays comfortable year-round. At GSMS, we use only the highest quality products from leading manufacturers, guaranteeing efficient and long-lasting solutions for your HVAC needs. Whether you need a quick repair, a complete system installation, or regular maintenance, our team is dedicated to providing personalized service tailored to your specific requirements. Don’t let HVAC issues disrupt your comfort—call GSMS today at 603-424-8258 to schedule your HVAC service in Londonderry, NH, and experience the difference of working with trusted local professionals.
In addition to our heating and air conditioning services, we offer top-quality plumbing services to the residents of Londonderry, NH. With over three decades of experience, our family-owned business has established a reputation for trust, reliability, and exceptional customer care. Our comprehensive plumbing services include water heater repair, replacement, and maintenance for both tank and tankless models, ensuring your home has a consistent supply of hot water. We also specialize in kitchen plumbing, from faucet and sink installations to dishwasher and water line services. In the bathroom, our expert plumbers handle everything from toilet and shower repairs to vanity plumbing and pipe replacement. At GSMS, we use only the highest quality materials and the latest techniques to provide efficient and long-lasting solutions for your plumbing needs. Whether you require a quick repair, a complete installation, or regular maintenance, our team is committed to delivering personalized service tailored to your home’s unique requirements. Don’t let plumbing issues disrupt your daily routine—call GSMS today at 603-424-8258 to schedule your plumbing service in Londonderry, NH, and experience the peace of mind that comes with working with trusted local professionals.
Recent Jobs and Reviews in Londonderry, NH
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Job Locations and Reviews
Completed the mini split maintenance today. Everything went great. Please see the attached form.
Washed outdoor coil added 2lbs r-22
Mice chewed up wires.
Found that the outdoor units coil has a big leak. Waiting to hear back from Mitsubishi parts to see if there is availability on a coil or unit. Zak will come out to give an estimate on adding a new unit for the son and daughter's bedroom or replacing the old unit and adding four heads onto it.
GSMS HomeClub plumbing visit & replace aquastat on indirect water heater.
Project Overview This option provides a highly efficient, 2-zone ductless system designed to condition the main living area and the rear second-floor bedroom. This is a cost-effective solution utilizing standard heat pump technology for excellent summer cooling and efficient supplemental heating during the spring and fall shoulder seasons. Scope of Work 1. Indoor Equipment First Floor: Install one (1) wall-mounted ductless head at the foot of the staircase to handle the primary first-floor load. Second Floor (Rear Red Bedroom): Install one (1) wall-mounted ductless head on the backyard-facing wall, positioned above the existing mirror. 2. Performance & Temperature Expectations Second Floor Distribution: The unit in the rear red bedroom is designed to condition that specific room and blow conditioned air out into the hallway to assist the front office and primary bedroom. Important Note: Because there are no dedicated indoor units in the front rooms with this option, there will
AC maintenance agreement. No issues were found.
Completed the AC maintenance today. Everything went great. Please see the attached form. I emailed over the invoice because service titan was not working.
Completed the central air and the mini split maintenance. Everything went great. Please see the attached forms.
Completed the AC maintenance today. Everything is running great. Please see the attached form.
Completed the central air and the mini split maintenance today. Everything went great! Please see the attached form. The office will be in touch regarding the HRV maintenance.
Planned AC service as part of maintenance agreement. Everything looked good. I repaired a few electrical connections in both condensers.
Add refrigerant to systwm not cooling. Gina will reach out to schedule system replacement estimate with Zak.
Ductless condensate pump was gunked up. This caused the float switch to stick. I removed and cleaned. I tested operation and added a special cleaner to the system. We will make note to continue chemical treatment on all ductless units in the facility, moving forward.
Connected ice maker line to valve in pantry closet also replaced toilet flapper
Replace control board.
Today I replaced 2 outdoor water spigots with new frost free versions. I reccomend a water test due to the old hoses being stuck on and the appearance of a lot of the fittings in the basement. I reccomend replacing irrigation valve and the hose/ drain valve below it.
GSMS HomeClub AC visit. All 3 systems serviced. I only had to replace the filter for upstairs Mitsubishi system. The furnace had a spare filter by the side that I replaced. Thank you!
Replace 1/2" valve due to old stop and waste leaking.
Upon further investigation, it was determined that the Daikin mini-split unit in the elevator room has a crack in the drain pan which is further causing the leak. For this Daikin unit, the drain pan is a part of the bottom frame assembly and will require us to replace that section. This repair will be completed.
This proposal outlines the complete replacement of your existing Lennox R-410A two-zone mini-split system. We will be upgrading the equipment serving your Master Bedroom and Great Room to ensure reliable, high-efficiency cooling and supplemental heating. To provide the most cost-effective and clean installation possible, we will be reusing the Fortress line hide and heavy-duty exterior wall bracket that our team previously installed, while completely replacing all the internal working components (copper, wiring, and equipment). Scope of Work 1. Equipment Removal & Preparation Safely disconnect, recover existing refrigerant, and remove the failing Lennox indoor and outdoor equipment. Prepare the existing GSMS-installed outdoor wall bracket to accept the new condenser. 2. New Indoor & Outdoor Equipment Indoor Air Handlers: Supply and install two (2) perfectly sized, high-efficiency wall-mounted ductless heads located in the Master Bedroom and the Great Room. Outdoor Condenser: Su
Found that the thermostat wire was grounding out somewhere. I used one of the extra thermostat wires.
Performed a deep cleaning on the mini split head in the IT room. I took a before and after video. Turned it back on to 64 degrees in cooling mode.
Primary side of transformer shorted out. Caused by power issue on 3/17. I replaced and tested operation. We will order limit switches to replace to help prevent intermittent low voltage short issue.
Both boilers faulted out. See invoice line item for details. Thank you!
Excellent Service
Working with GSMS was a fantastic experience. There was attention to detail from the estimate to the clean up at the end of the project. Especially during the planning process, Zak helped me evaluate different options, quickly readjusted as I changed my mind... without ANY pressure! Superior, prompt communication during the whole (and post) process.
Jack did a great job at my home today. GSMS is a fine company to do business with. Unlike many they know what they are doing ! I appreciate their work.
Hi, Art! Zak here - Thank you for your kind words! We work hard every day for our amazing clients like you!
Excellent service
GSMS installed my furnace in 2018, Mark and Team are the only service providers that I will use. Mark is very knowledgeable and has shared some knowledge how’s with me.
Thank you so much for this 5-star review. We really appreciate you being a customer and helping to share the word about us. We’re here for you anytime.
Excellent Service!
Excellent Service!
Jack is always very knowledgeable and kind and helpful when servicing our home. Thank you!
We're thrilled to hear that you enjoyed your experience with us. Thanks for the kind words!
Service with a smile
Thanks for sharing your review with us and the community.
👍
We thank you for sharing your positive experience. It made our day.
We are so glad to have found GSMS. Jack is very knowledgeable and courteous. We had a bad experience with our previous company and really needed to find someone who services System 2000. We are very pleased with the work and would highly recommend them. Their prices are very fair too.
A very nice young man that replaced my condensate pump and did a nice job. He represents GSMS as a Pro just like the rest of the group. You can not go wrong with this company.
Thank you so much for taking the time to leave us this amazing review!
Excellent service
Excellent Service







