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Exeter, NH

Gsms In Exeter Nh At Dodges Agway

Your Trusted Heating, AC & Plumbing Experts in Exeter, NH since 1987

When something goes wrong with your heating, cooling, or plumbing, you don't want to wait around for a company that has to look up where Exeter is. GSMS has been serving Exeter and the surrounding Seacoast area for nearly four decades, and our service specialists know these neighborhoods, these homes, and the kinds of systems that run in them.

Whether you need a furnace repaired before a cold snap hits, a new AC system installed before summer, or a plumbing issue resolved before it turns into something bigger, we're ready to help. Give us a call at 603-424-8258 or contact us online.

FAQs about HVAC and plumbing service in Exeter, NH

Services we provide in Exeter, NH

Heating

New Hampshire winters are no joke, and Exeter homes need heating systems they can count on. Our service specialists install, maintain, and repair all types of heating systems, including furnaces, boilers, and heat pumps. Whether your system needs a tune-up heading into winter or it's stopped working altogether, we'll get you taken care of quickly.

  • Furnace installation and repair
  • Boiler installation and repair
  • Heat pump installation and repair
  • Heating system maintenance
  • Emergency heating service

Air conditioning

When summer arrives in the Seacoast region, you want to know your AC is ready. GSMS installs and services central air conditioning systems and ductless mini-splits, so whether you're cooling a whole house or a specific room, we have a solution that fits.

  • Central AC installation and repair
  • Ductless mini-split installation and repair
  • AC maintenance and tune-ups
  • Emergency cooling service

Indoor air quality

Most Exeter homeowners don't think about the quality of their indoor air until something feels off. Dry air in the winter, musty smells, allergy symptoms that won't quit, or a home that just never feels quite comfortable can all point to an air quality issue. Our service specialists can run a full in-home air quality assessment using our Air Advice diagnostic tool and recommend exactly what your home needs.

  • Whole-home humidifiers and dehumidifiers
  • Energy recovery ventilators (ERVs)
  • UV in-duct air purifiers
  • High-efficiency air filtration
  • In-home air quality assessments

Plumbing

From a dripping faucet to a full water heater replacement, GSMS handles plumbing jobs of all sizes for Exeter homeowners and local businesses. Our service specialists are trained to diagnose problems quickly and give you straightforward answers about what needs to be done and what it will cost.

  • Water heater installation and repair
  • Tankless water heater installation
  • Leak detection and repair
  • Drain cleaning and clearing
  • Water filtration and softener systems
  • Kitchen and bathroom plumbing
  • Reverse osmosis systems

Why Exeter homeowners choose GSMS

There's no shortage of HVAC and plumbing companies serving the Seacoast area, so we don't take it for granted when a homeowner calls us. Here's what we hear most often from our Exeter customers about why they keep coming back.

We're a local, family-owned business. GSMS was founded in 1987 by Mark Downing and is now led by his son Zak as a second-generation owner. We're 100% locally owned and operated, which means when you call us, you're calling a neighbor, not a call center.

We send service specialists, not just technicians. At GSMS, we don't use the word technician. Our team members are service specialists because their job goes beyond fixing the immediate problem. They take the time to understand your system, explain what they find, and make sure you feel confident in every decision you make.

We've been doing this for a long time. Nearly four decades of serving New Hampshire homeowners means we've seen just about everything. That experience shows up in the speed and accuracy of our diagnostics, the quality of our installs, and the relationships we've built with customers who have trusted us for years.

We stand behind our work. We offer some of the best warranty options available, and we only install products from brands we trust and know how to service. When we leave your home, the job is done right.

Ready to schedule service in Exeter?

Whether it's a heating emergency, a plumbing repair, or you're just due for a maintenance visit, GSMS is ready to help. Our service specialists serve Exeter and the surrounding Seacoast area, and we're known for showing up on time, communicating clearly, and getting the job done right the first time.

Call us at 603-424-8258 or contact us online to schedule your appointment. We look forward to earning your trust.

Recent Jobs and Reviews in Exeter, NH

Job Locations and Reviews

Completed the AC maintenance, furnace maintenance and the tankless water heater maintenance. Everything went great today! Please see the maintenance forms that are attached to the email.
Completed the AC maintenance, furnace maintenance and the tankless water heater maintenance. Everything went great today! Please see the maintenance forms that are attached to the email.
Qwentin G.
Qwentin G. Checked in
Completed the AC maintenance, furnace maintenance and the tankless water heater maintenance. Everything went great today! Please see the maintenance forms that are attached to the email.
Exeter, NH 03833
Mark D.
Mark D. Checked in
Installed shower head
Exeter, NH 03833
Qwentin G.
Qwentin G. Checked in
Completed the mini split maintenances today. I started off with washing both outdoor units coils with water. I cleaned the outside of the units with a cleaner and a rag. I checked electrical connections and everything was good. I went inside next and I cleaned both of the indoor heads coils with coil cleaner. I washed the filters with soap and water. I replaced the two return filters for the unit in the attic. Lastly I ran all the units in max heating and my supply temperature was 120°. Everything was running very good!
Exeter, NH 03833
Qwentin G.
Qwentin G. Checked in
Completed the AC maintenance. Started off at the outdoor unit. I checked all the wiring connections and the capacitor and everything was good. I washed the coil with water and coil cleaner. Inside I flushed and brushed out the trap with cleaner. The client replaces her own air filters. Lastly I ran the unit and all my readings were coming back great!
Exeter, NH 03833
Mark D.
Mark D. Checked in
Replacement of existing corner shower, 34" x 34". We will remove existing shower unit, glass enclosure, and old plumbing as needed. For the tile floor, the goal is to chip away the mortar edge between the tile and the existing shower base. If this is achieved, there will be minimal finish work required afterward. In the worst-case scenario, the first row of tiling closest to the existing shower base will need to be removed. A new MAAX rounded corner 32" shower will be installed in place. A matching MAAX glass sliding door enclosure will also be installed for the unit. The glass enclosure has a polished chrome finish with clear, smooth glass. A standard Moen Chateau shower valve with a shower arm will be installed in polished chrome. The client will source and provide a showerhead to be installed. The client is responsible for finish work - including drywall edging around shower walls (where drywall abuts shower walls) and tile flooring. GSMS will dispose of trash/debris.customer wi
Exeter, NH 03833
Exeter, NH - New Fujitsu remote holder as top right tab snapped off of original holder.
Zak D.
Zak D. Checked in
New Fujitsu remote holder as top right tab snapped off of original holder.
Exeter, NH 03833
Mark D.
Mark D. Checked in
Installed. New water lines&jack installed new heater.Jack will finish heater tomorrow and install toilet.I need to go back to install plumbing and pump to new sink.Also Eric wants hot and cold outside faucet
Exeter, NH 03833
Boiler PM on Ideal high efficiency boiler. Everything went great. Please see the maintenance form for details of todays servicing. Thank you!
Boiler PM on Ideal high efficiency boiler. Everything went great. Please see the maintenance form for details of todays servicing. Thank you!
Jack D.
Jack D. Checked in
Boiler PM on Ideal high efficiency boiler. Everything went great. Please see the maintenance form for details of todays servicing. Thank you!
Exeter, NH 03833
Jack D.
Jack D. Checked in
Low psi. Filled up. No visible leaks anywhere. Heat is working.
Exeter, NH 03833
Mark D.
Mark D. Checked in
Estimate for plumbing repairs
Exeter, NH 03833
Qwentin G.
Qwentin G. Checked in
I found that the cold water inlet line going to the boiler had a leaking 90. I also found that the boilers water filter nut was a little loose. I cut out the old 90 and replaced it with a new one and I tightened up the nut for the filter.
Exeter, NH 03833
Review
Great service again. On time and professional. I highly recommend GSMS.
Katherine Turner - Exeter, NH 03833
Response from GSMS Air•Heating•Plumbing:

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

Jack D.
Jack D. Checked in
Everything went great with your Rinnai tankless water heater service. There are no reccomended repairs to be made. I removed the shower heads and cleaned out the flow restrictor to improve water pressure. Thank you!
Exeter, NH 03833
Adam P.
Adam P. Checked in
The existing Daikin system that provides cooling and heating for the main living floor and primary bedroom will be replaced. The existing locations and placement will be reused to retain the current design aesthetics. A second new mini-split system will be installed to provide cooling for the second-floor boys' bedrooms. Designed as a mini-ducted unit, the small air handler will be placed in the attic with the necessary short lengths of ductwork to feed the two bedrooms with a dedicated supply and filter return. Due to ceiling / wall limitations, the return register for the smaller bedroom may need to be located in the hallway (this will not impact efficiency). The new mini-split system outdoor unit will be located on the "garage side" of the home, tucked in the corner, as discussed. The line hide will run up the exterior to the attic location. *Electrical panel will need to be upgraded to allow for future capacity. The price listed is a budget number and our electrical team will ne
Exeter, NH 03833
Qwentin G.
Qwentin G. Checked in
When I got to the clients house, I turned on the indoor unit and put the heat and fan speed at max. I used my temperature probes to check supply and return temperature. When the unit turned on and ran for about 10 minutes, I was getting 115° air coming out which is good. The temperature split was 45°, which is good as well. I went to the outdoor unit and checked it out. The only thing I noticed outside is that there was a good amount of snow and ice buildup on top of the unit. I cleaned the snow and ice off of the unit. I believe the reason why the unit wasn’t turning on before was because snow got inside of the unit and built up ice around the fan which caused the unit to not be able to produce heat.
Exeter, NH 03833
Mark D.
Mark D. Checked in
Conversion of failing oil-fired boiler with indirect hot water tank for domestic hot water to our new GSMS Choice Ideal high-efficiency gas combi boiler. The system will remain as a two-zone system, serving the first floor and the second floor. New basic programmable thermostats will be installed for control. Boiler location will be placed in the front of the basement area where the existing oil tank is. The oil tank will be removed and recycled for proper disposal. We will utilize the existing two holes as best to our ability to use for the new venting of the boiler. All piping will be carried over to the new boiler location. The existing boiler and indirect will be properly recycled and the thimble for the boiler into the chimney will be capped off. On the first floor, due to remodeling, baseboard will be modified. A toe kick unit will be installed underneath the 36" sink cabinet for the kitchen / entry area. A new length will be added underneath the new TV location, on the back w
Exeter, NH 03833
Mark D.
Mark D. Checked in
Made system one zone. NO CHARGE IF YOU GO WITH NEW SYSTEM
Exeter, NH 03833
Jack D.
Jack D. Checked in
Fixed boiler heating zones that would not shutoff. Zone valves were stuck. We will reach out to schedule an estimate for a boiler replacement and oil to natural gas conversion! We will also get back to you for shirts floor remodel heat re-installation,
Exeter, NH 03833
Mark D.
Mark D. Checked in
Connect gas stove and plumb in kitchen sink
Exeter, NH 03833
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