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Londonderry, NH

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

Rated 5.0 out of 5 stars based on 14 customer 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

Jack D.
Jack D. Checked in
Completed the mini split maintenance today. Everything went great. Please see the attached form.
Londonderry, NH 03053
Mark D.
Mark D. Checked in
Washed outdoor coil added 2lbs r-22
Londonderry, NH 03053
Jack D.
Jack D. Checked in
Mice chewed up wires.
Londonderry, NH 03053
Qwentin G.
Qwentin G. Checked in
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.
Londonderry, NH 03053
Jack D.
Jack D. Checked in
GSMS HomeClub plumbing visit & replace aquastat on indirect water heater.
Londonderry, NH 03053
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
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
Adam P.
Adam P. Checked in
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
Londonderry, NH 03053
Jack D.
Jack D. Checked in
AC maintenance agreement. No issues were found.
Londonderry, NH 03053
Qwentin G.
Qwentin G. Checked in
Completed the AC maintenance today. Everything went great. Please see the attached form. I emailed over the invoice because service titan was not working.
Londonderry, NH 03053
Qwentin G.
Qwentin G. Checked in
Completed the central air and the mini split maintenance. Everything went great. Please see the attached forms.
Londonderry, NH 03053
Qwentin G.
Qwentin G. Checked in
Completed the AC maintenance today. Everything is running great. Please see the attached form.
Londonderry, NH 03053
Qwentin G.
Qwentin G. Checked in
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.
Londonderry, NH 03053
Jack D.
Jack D. Checked in
Planned AC service as part of maintenance agreement. Everything looked good. I repaired a few electrical connections in both condensers.
Londonderry, NH 03053
Jack D.
Jack D. Checked in
Add refrigerant to systwm not cooling. Gina will reach out to schedule system replacement estimate with Zak.
Londonderry, NH 03053
Jack D.
Jack D. Checked in
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.
Londonderry, NH 03053
Mark D.
Mark D. Checked in
Connected ice maker line to valve in pantry closet also replaced toilet flapper
Londonderry, NH 03053
Jack D.
Jack D. Checked in
Replace control board.
Londonderry, NH 03053
Jack D.
Jack D. Checked in
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.
Londonderry, NH 03053
Jack D.
Jack D. Checked in
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!
Londonderry, NH 03053
Jack D.
Jack D. Checked in
Replace 1/2" valve due to old stop and waste leaking.
Londonderry, NH 03053
Jack D.
Jack D. Checked in
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.
Londonderry, NH 03053
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
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
Adam P.
Adam P. Checked in
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
Londonderry, NH 03053
Qwentin G.
Qwentin G. Checked in
Found that the thermostat wire was grounding out somewhere. I used one of the extra thermostat wires.
Londonderry, NH 03053
Londonderry, NH - 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.
Qwentin G.
Qwentin G. Checked in
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.
Londonderry, NH 03053
Jack D.
Jack D. Checked in
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.
Londonderry, NH 03053
Jack D.
Jack D. Checked in
Both boilers faulted out. See invoice line item for details. Thank you!
Londonderry, NH 03053
Review
Excellent Service
Guimont - Londonderry, NH 03053
Review
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.
Ethel - Londonderry, NH 03053
Review
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.
Art - Londonderry, NH 03053
Response from GSMS Air•Heating•Plumbing:

Hi, Art! Zak here - Thank you for your kind words! We work hard every day for our amazing clients like you!

Review
Excellent service
Alison - Londonderry, NH 03053
Review
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.
Lorralyn - Londonderry, NH 03053
Response from GSMS Air•Heating•Plumbing:

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.

Review
Excellent Service!
Frank - Londonderry, NH 03053
Review
Excellent Service!
Frank - Londonderry, NH 03053
Review
Jack is always very knowledgeable and kind and helpful when servicing our home. Thank you!
Alison - Londonderry, NH 03053
Response from GSMS Air•Heating•Plumbing:

We're thrilled to hear that you enjoyed your experience with us. Thanks for the kind words!

Review
Service with a smile
Guimont - Londonderry, NH 03053
Response from GSMS Air•Heating•Plumbing:

Thanks for sharing your review with us and the community.

Review
👍
Guimont - Londonderry, NH 03053
Response from GSMS Air•Heating•Plumbing:

We thank you for sharing your positive experience. It made our day.

Review
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.
Laura - Londonderry, NH 03053
Review
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.
Art - Londonderry, NH 03053
Response from GSMS Air•Heating•Plumbing:

Thank you so much for taking the time to leave us this amazing review!

Review
Excellent service
Alison - Londonderry, NH 03053
Review
Excellent Service
Frank - Londonderry, NH 03053
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