AHT Inc. Plumbing & Heating is a full service plumbing and heating contractor serving the Upper Valley region of Vermont and New Hampshire. Our plumbing and heating services are focused on alternative-energy technologies that utilize solar and solid fuel sources for sustainable on-grid or off-grid plumbing and heating solutions. AHT Inc. specializes in comprehensive system design, installation and service of energy-saving plumbing and heating systems for residential and commercial clients.

Highlights, Specialties & Features

  • Comprehensive System Design, Installation & Service of Energy-Saving Plumbing & Heating Systems
  • Sales, Installation & Service for Viessmann Heating Systems: Oil. Gas, Wood & Solar
  • Alternative-Energy including Solar & Solid Fuel sources for On-Grid or Off-Grid Plumbing & Heating
  • Radiant Heat & Radiant Floor Heating Systems

Professional Associations & Certifications

  • Renewable Energy Vermont
  • Vermont (VT) & New Hampshire (NH) Licensed Master Plumber

Serviced Areas

  • Upper Valley Region of Vermont & New Hampshire (VT, NH) ; Orange County, Windsor County, Windham County, Rutland County, Grafton County, Sullivan County, Merrimack County

Payment Options

  • Credit Terms Available, Personal Checks

Contact Details

  City Sharon, VT
  Zip Code 05065
  Address 5632 Vermont Route 14
  Phone Number (802) 763-2200

Products & Services

Comprehensive Plumbing & Heating System Design, Installation & Service

AHT Inc. Plumbing & Heating strategically designs all of the plumbing and heating systems we install in order to allow for the most efficient, reliable, and optimal work product. We do not rely on our suppliers for system design, as some other companies do. Since we design everything we install from the ground up, we have a far greater understanding of the systems that we build. With this knowledge, we are able to make each plumbing and heating system fit the site-specific needs of the customer with minimum waste, maximum efficiency and absolutely no trial and error involved. We only install materials and apply practices that have a proven performance record, ultimately insuring your comfort and the long-term security of your home or business.


AHT Inc. Plumbing & Heating is first and foremost a plumbing company. All of our employees are licensed Master Plumbers or Apprentice Plumbers in the State of Vermont. We take great pride in our craft and honor being part of the tradition of the American plumbing trade. AHT Inc. specializes in all types of plumbing. We install complete drain, waste, ventilation and water distribution systems in new construction and remodeled homes and businesses. From a single bathroom fixture replacement to refurnishing a multiple bathroom home, AHT Inc. has the knowledge and experience to get the job done right the first time, resulting in years of trouble-free operation and comfort for our customers.

Wells, Pumps & Water Filtration

AHT Inc. Plumbing & Heating is fully equipped to install all types of well and water pumps. We perform new installations and replacements of submersible pumps, jet pumps and pressure tanks as well as water filtration systems. In the event of an issue with your systems, AHT Inc. does trouble-shooting to assess and locate the problem so we may address it correctly to get your water flowing again in as little time as possible. Where pumps are called for, we prefer to install Grundfos SQE constant pump systems. These constant pump systems supply an even pressure to the fixtures in your water line by steadily increasing pump speed as multiple faucets or taps are opened. By utilizing this approach, undesirable swings in pressure are eliminated regardless of the overall system demand. The result is a smooth operating water system combined with a reduced overall electrical consumption.

Outdoor Reset & Weather Responsive Control

AHT Inc. Plumbing & Heating employs weather responsive controls in all of our heating systems to ensure peak efficiency. Weather responsive controls, otherwise known as outdoor reset, accommodates the change of supply temperature to the heating circuits by factoring the desired inside temperature and existing outdoor temperature. The colder it is outdoors, the higher the temperature that will be required to meet the desired temperature indoors. However, when it's warmer outside, supply temperatures can be dropped substantially to conserve energy. By taking the outdoor temperature into account, your heating system can be controlled to run at its peak efficiency and comfort level with no wasted energy.

Radiant Heating System Installation

AHT Inc. Plumbing & Heating prefers radiant heating systems when considering optimum comfort and efficiency for our clients. The simple fact is that a larger thermal mass can heat a larger space while using lower water temperature than that of a smaller thermal mass. AHT Inc. prefers to rely on radiators and radiant heating zones as much as possible (greater thermal mass) as opposed to finned baseboard heaters (lesser thermal mass) because of this fact.

These systems normally include conventional radiator heating and radiant floor heating zones, although entire ceilings and walls may also be utilized in radiant heating system design. While many people think of the uncomfortable nature of older cast iron radiators when it comes to radiant heating, and many seem to recall them being too hot to touch, inefficient and loud, this is no longer the case when a radiator system is used with condensing boiler technologies. When utilized in this manner, even old-fashioned cast iron radiators are actually a safe, efficient, quiet and comfortable heating source. Whether you have them in an existing home, are doing a restoration or just plain like the old style and aesthetics, they may be retrofitted to work extremely well with condensing gas boilers and outdoor reset temperature controls.

One of the greatest advantages in radiant heating systems is the constant water circulation during each heating cycle (moving the water constantly through the radiator during the heating program) . Using this model in combination with a weather responsive control sensor, radiant heating systems may be kept at a temperature that will heat your space to an even comfort level in a highly efficient manner. Instead of the on-and-off high temperature cycles consistent with non-condensing boilers, radiant heating systems combined with condensing boilers allow for even greater efficiency by allowing for constant water circulation with lower water temperatures. By installing a radiant heating system and condensing boiler that will allow for constant circulation of water during a heating program, both efficiency and comfort are increased while room temperature fluctuations are eliminated.

Solar Hot Water

AHT Inc. Plumbing & Heating firmly believes in the use of solar hot water to augment your existing domestic hot water or heating system. What could be a better energy source than the sun? Utilizing the highest quality equipment from Viessmann, solar thermal energy can be harvested all year round for your domestic hot water needs. When solar hot water is used in a well-insulated building, it may even be able to supplement your existing heating system. Solar hot water is an excellent way to reduce your consumption of fossil fuels and save money along they way. All of our solar hot water systems meet the highest mandated efficiency ratings and may be eligible for federal and state tax credits, which can cover a significant percentage of total installation costs.

Solid Fuel Boilers

AHT Inc. Plumbing & Heating strongly advocates the use of solid fuel boilers. Let's face it, we're in New England and we have easy and immediate access to wood fuels, one of the most renewable and cost-stable heating fuels in the world. Many of us already have wood burning stoves at home and use them to offset our volatile heating fuel costs. The logical step is to employ this same fuel which is very literally in our own backyard to heat our domestic hot water and fuel hydronic heating systems.

There are now boilers on the market that burn cordwood (or pellets) and are capable of Annual Fuel Utilization Efficiency (AFUE) ratings of over 93%. This is a 5% higher efficiency rating than even the best oil burning boilers that are rated at 88%. Wood burning boilers are even considered to be near carbon neutral as the fuel they burn absorbs Carbon Dioxide (CO2) as it grows. With this in mind, it is important that any fuel is burned as efficiently and cleanly as possible to avoid unnecessary waste and pollution.

In most cases, when a wood-fired boiler is installed, an oil or gas boiler is already in place for use as a back up, or for seasons when burning wood is not as practical. For many of the higher efficiency wood-boilers, a thermal storage tank is required to maximize efficient combustion in the boiler. By burning a wood fire hot and thoroughly, the fire is not dampened to smolder and won't create toxic creosote as a byproduct. While this type of system cannot utilize all the heat produced in this manner, the heat may be stored in a thermal storage tank for later distribution.

This method, along with connecting to a back-up boiler requires that piping and controls be designed and arranged to make the system operate with maximum efficiency. AHT Inc. is well versed in these techniques and can design an elegant and efficient system so you can take advantage of this readily available renewable resource to supplement your current heating system.

Condensing Gas Boilers

AHT Inc. Plumbing & Heating strongly recommends condensing gas boilers when gas (propane) is used. Propane is a good clean burning fuel and generally requires less maintenance and cleaning than oil-fired boilers do. A gas boiler needs cleaning only every two to three years since the fine gas particles contain less volume to create sooty compounds. As a byproduct of petroleum, propane is just as finite in supply and as subject to price fluctuations as oil and gasoline are. If using propane as a heating system fuel, we must endeavor to burn as little of it as possible. Therefore, we recommend using condensing gas boilers as opposed to non-condensing gas boilers.

Condensing gas boilers are the clear solution for a number of reasons, including overall efficiency and simplicity of system design. Even the very best non-condensing gas boilers can only come close to an 86% Annual Fuel Utilization Efficiency (AFUE) rating. Additionally, they have a minimum return water temperate of 135 degrees, which is the "dew point" that the flue gas will begin condensing inside of the boiler, creating highly corrosive acidic compounds which will eat through cast iron and cause the system to leak. This is a problem with modern radiant panel systems that require supply temperatures well below this dew point. As a result, the boiler temperature must be higher than the emitter requires. This scenario, combined with the fact that every 3% we lower the water temp equals a 1% reduction in fuel costs, poses a definite argument for the use of condensing gas boilers.

A perfect solution for gas-fired boilers may be found in the Viessmann Vitodens line of condensing gas boilers, which are by far the best design in the world, especially when compared to other products readily available in the U. S. Utilizing Inox stainless steel heat exchangers and burners, Vitodens boilers are designed to handle the acidic condensate created by low boiler water temperatures. They not only handle the condensates' corrosiveness but actually extract the latent heat in the condensate as it falls back down the flue pipe and on the return water section of the Inox heat exchanger.

This means that we can utilize these boilers to supply the low temperatures that radiant panel heating systems require (directly from the boiler with no mixing valve required) and lower the flue gas (exhaust) temperature well below its dew point of 135 degrees. Given that exhaust temperatures for most conventional gas boilers are in excess of 400 degrees with the excess heat from the flue gas being exchanged into the return piping of the boiler, a condensing gas boiler is clearly the more efficient solution. The significantly higher 94% AFUE rating of the Vitodens doesn't even take into account the heat gain from condensing flue gas.

The Vitodens boiler design is perfectly suited for today's modern radiant heating systems, including radiant floor and panel radiator heating systems. The Vitodens line is remarkably quiet, making no more noise than a refrigerator when running. Vitodens boilers do not require a masonry chimney and may either be vented through a side wall or vertically by using their own specialized concentric vent piping, allowing for much more flexible installation requirements.

Emergency Service

AHT Inc. Plumbing & Heating upholds all our product warranties, installations and repairs while retaining a backup inventory of parts in the rare event that an emergency service call requires immediate product replacement. In the event that our clients should ever encounter a problem with a plumbing or heating system we have installed, we offer emergency service seven days a week with at least one employee on call at all times, including 24 hour emergency service for our Viessmann line of products.

  • I would recommend this business
  • cost effective,

"We had AHT Inc. replace our heating system, a 1987 vintage 150,000 BTU Power vented propane gas boiler and an 80 gallon indirect fired water heater with baseboard radiation. They installed a Viessmann Vitocell 200B dual coil indirect water heater, using our old water heater for supplemental space heating and replaced the baseboard with Radson panel radiators. In addition, they installed 64 Vitosol 200 vacuum tube solar collectors to supplement our hot water and radiant heating.

We didn't do any substantial building or envelope improvements and in fact ended up adding an additional 1600 square feet of space with two new residential apartments. In one year our fuel consumption dropped from 1679 gallons to 960 gallons, even after we added an additional 1600 square feet of space. The installation of the new condensing gas boiler and solar panels to supplement our hot water has provided a huge savings for us. Thanks AHT Inc.!

Value for moneyOur fuel consumption dropped from 1679 gallons to 960 gallons
Service & support
Overall ratingExcellent