
Your Trusted Heating & AC Repair Experts in Amherst, NH
Since 1987, GSMS has been proud to offer top-notch HVAC services to residents of Amherst, 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.
Get the Best HVAC Service in Amherst
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 heating and cooling service in Amherst, NH, and experience the difference of working with trusted local professionals.
- Furnace Repair: Is your furnace blowing cold air or refusing to turn on? Our certified techs are trained to service all major brands. We’ll get your heat back fast.
- New Furnace Installation: Upgrading your heating system? We install energy-efficient gas furnaces, electric furnaces, and hybrid systems designed for winters.
- Heat Pump Repair: Troubleshoot and repair heat pumps for both heating and cooling issues, including compressor failure and refrigerant leaks.
- Heat Pump Installation & Replacement: Looking to upgrade to an energy-efficient heat pump? We’ll help you choose the right system and install it with precision.
- HVAC Maintenance & Tune-Ups: Annual maintenance keeps your system running efficiently and avoids unexpected breakdowns. Our furnace tune-up service includes inspection, cleaning, and performance checks. Prevent breakdowns and high energy bills with seasonal AC maintenance. We clean coils, check refrigerant levels, and test performance.
- AC Repair Service: If your air conditioner isn’t cooling, is leaking, or making loud noises, don’t wait. We handle repairs quickly and professionally.
- Air Conditioning Installation: Need a new system? We replace central AC systems and high-efficiency cooling units sized for your home and budget.
- Ductless Mini-Spilt Systems: Our expert technicians are also skilled in installing and maintaining ductless mini-splits, 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.
- Indoor Air Quality Solutions: Dust, allergens, and humidity making life uncomfortable? We install whole-home air purifiers, dehumidifiers, and advanced filtration systems.
- Duct Cleaning Services: Clogged air ducts can reduce airflow and raise energy bills. Our air duct cleaning improves HVAC efficiency and air quality.
- Humidity Control: From humidifiers to dehumidifiers, we help you balance indoor moisture for health, comfort, and HVAC performance.
Expert Plumbers Serving Amherst
In addition to our heating and air conditioning services, we offer top-quality plumbing services to the residents of Amherst, NH. With over three decades of experience, our family-owned business has established a reputation for trust, reliability, and exceptional customer care.
- Water heater repair, replacement, and maintenance for both tank and tankless models.
- 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 Amherst, NH, and experience the peace of mind that comes with working with trusted local professionals.
Recent Jobs and Reviews in Amherst, NH
Our Local Reviews by City
- Amherst, NH (3)
- Atkinson, NH (1)
- Auburn, NH (1)
- Barrington, NH (12)
- Bedford, NH (14)
- Candia, NH (2)
- Chester, NH (1)
- Concord, NH (5)
- Derry, NH (2)
- Dover, NH (1)
- Epping, NH (1)
- Gilmanton, NH (1)
- Goffstown, NH (3)
- Henniker, NH (2)
- Hillsborough, NH (1)
- Hollis, NH (7)
- Hooksett, NH (5)
- Hudson, NH (4)
- Lee, NH (1)
- Londonderry, NH (10)
- Manchester, NH (33)
- Merrimack, NH (14)
- Milford, NH (3)
- Moultonborough, NH (1)
- Nashua, NH (19)
- New Boston, NH (3)
- Northfield, NH (1)
- Northwood, NH (1)
- Pembroke, NH (1)
- Raymond, NH (1)
- Rochester, NH (2)
- Salem, NH (3)
- Sandown, NH (1)
- Stratham, NH (1)
- Weare, NH (4)
- Windham, NH (6)
Job Locations and Reviews

I found out that the zone dampener was being opened to the second floor when the first floor was calling for heat. The thermostat wires going through the wall to the upstairs thermostat were shorting out to each other creating a call when the first floor would turn on. I talked to the client and the only way to solve that is to use a Wireless thermostat. The client wanted to update all three of his thermostats as well. I performed a maintenance on both Lennox and Mitsubishi mini splits. I started with cleaning them both from the inside out with water. I cleaned the outside of the unit as well. Everything looked great. Inside I washed the air filters with Dawn soap and water. I cleaned the indoor coils as well with Dawn soap and water. All the mini splits were in very good condition.

Replace check valves and corroded copper elbow fitting. Replaced sprinkler shut off valve

Replace

The upstairs bathroom under sink drain piping was back pitched towards the trap, I reccomend replacing the drain piping. The upstairs bathroom faucet has an aerator cap that leaks. I tried tightening it but the threads are no good on it. The upstairs bathroom tub spout diverter doesn't seal and the shower valve cartridge does not seem to seal when in the off position. The basement bathroom toilet is wobbly, I tried tightening the flange nuts but they are plastic and will not tighten enough. The basement bathroom sink drains very slowly due to not having a vent.

Removed shower drain,recaulked drain and installed

I replaced the expansion tank and relief valve which had both failed. I diagnosed the humidifier that was not working. The flow restrictor was clogged. I replaced the humidifier pad as well. I resent the estimate to replace the check valve for the basement heat loop. I also will get back to you in regards to the third zone above the garage once I talked to the install team and system replacement designer. Thank you.

Run new 2” pvc line to existing 3” abs line

The drain is draining fine. It is only slow when large amounts are drained at once. I believe there new basket strainer is more restrictive than before.

Cutout 3” elbow and replace with a new one. Test for leaks.

Furnace maintenance completed on Lennox signature series propane furnace. New humidifier pad was installed today. Everything looked great thanks!

Estimate for washing machine hook up
First time, here.Wonderful guys, great work. See them, next year!

Pm on furnace

Everything went well with the maintenance on your Rheem furnace. I only had to adjust the low fire gas manifold pressure. I found fitting on the vent pipe to have a small leak that had condensation on it. I taped the fitting for temporary fix but I will send an estimate for the repair.

Call back so diagnostic is waved.

Installed new garbage disposal and switch.Repaired first floor toilet
Great

I replaced the basket strainer and the tail piece. They were both corroded and frail. I tested it for leaks and all is well. Thank you!

Repaired 3” vent through roof,

The HomeClub heating maintenance visit went great! I went through each furnace and checked safeties, cleanliness, electrical connections, and gas pressures according to manufacturer specifications. The Bryant furnace in the attic did not require any adjustments. The Whirlpool furnace in the basement needed a slight gas adjustment. Both air filters looked clean so I did not replace them. Thank you and see you next time!

Cleared the kitchen drain with snake and used the rest of the drain after I pushed the blockage out into the main. We ran water and tested operation. I recommend replacing the copper drain tail piece as the bottom is brittle and breaking.

Check flashing she is going to call and set appointment when roofer is here

Removed toilet installed spacer and new gasket.ALSO REPLACED FLAPPER

Repaired a Navien NPE-240S tankless water heater with an issue of inconsistent hot water supply near Amherst. Diagnosed the problem as a malfunctioning flow sensor. Replaced the faulty sensor with a new OEM part and cleaned the heat exchanger to remove scale buildup. After reassembling the unit, performed a system check to ensure consistent water flow and temperature stability. The heater is now operating correctly and the customer is pleased.

Completed a water heater installation in Amherst using customer purchased AO Smith ProLine XE 50-gallon gas model. Removed the old unit, installed the new heater on a stable platform, and connected the water supply lines with new brass fittings. Set up the 3-inch venting system to ensure proper exhaust and connected the gas line with a secure seal. Filled the tank and tested the system for leaks, then adjusted the thermostat for optimal performance.
We have used GSMS for years and have always been very pleased with their service!
Love to hear it, Maria!! Thank you for taking the time to shout out our awesome team.

Cleaned shower head.

Removed pressure switch and cleaned pressure port/repaired two leak and replaced bath rm sink shut off.