Boilers and Radiant Heating

Click on the manufacturers listed below to go to their websites for viewing the many products in stock at DESCO Energy. Click on the logos or underlined blue text to go to the manufacturers' websites. Choose from a wide array of manufacturers including New York Thermal Inc., New Yorker Boiler Company, Peerless Boilers, Takagi, Taco, Zurn, Watts Regulator and Watts Radiant as well as Amtrol. For assistance call us toll free at 877-265-9764 or email info@descoenergy.com

Click here to find answers to the most frequently asked questions.

Manufacturer of Steel and Cast Iron Boilers for Gas and Oil

Manufacturer of Wall Hung Boilers and Instantaneous Water Heaters

Manufacturer of Cast Iron Gas Fired Boilers

Manufacturer of Indirect Water Heaters and Expansion Tanks

Manufacturer of Boiler Hydronic Components and radiant floor heating systems and tubing

Manufacturer of Pumps, Valves and Controls for radiant and baseboard heating systems

Manufacturer of PEX tubing, fittings, manifolds, heat transfer plates and controls


Gas Boilers

High Efficiency Condensing Boiler. Also available with Domestic Hot Water Trinity Wall Mount 94% AFUE Modulating with Hot Water Reset. The most efficient boiler in the market today with the most energy efficient features. DESCO Energy is the largest distributor of Trinity boilers on the internet and on the Northeast part of the country.


For more information click here


Standard Efficiency Wall Mount Boiler


The Takagi wall mount boiler with 83% AFUE

Sidewall venting


For more information click here

Standard Efficiency Cast Iron & Steel Boilers

From 78-87% Efficiencies


For more information click on the pictures above


Oil Fired Cast Iron & Steel Boilers

From 80-88% AFUE

For more information click on the links above


Boiler Accessories

Concentric Vent Kit

Vent Wall Termination Kit

Propane Conversion

Thermostats Pumps Controls

Fill Valves - Expansion Tanks - Air Scoops

Indirect Water Heaters




To get started click on any of the blue words in this introduction for a more complete explanation. DESCO Energy and SEER Solutions for Energy Efficient Results will guide you through the entire process of sizing and selecting the most efficient system for your house or business. We recommend all potential customers review all the information provided in our Getting Started and Solutions section of the web site. When you're ready an Online Sizing Form using Manual J is provided to complete with detailed construction and sizing of your home including location and insulation values to determine the exact heating and air conditioning requirements of your building. This valuable information provides the necessary information to accurately select and size the heating and air conditioning system that's right for you.


Boilers are rated for efficiency and capacity.  Efficiency is rated in levels of AFUE or Annual Fuel Utilization Efficiency. Capacity is rated in BTUS. Today's new more efficient systems have more technical features which can save more energy than what the AFUE rating describes. The vast majority of homes with hydronic heating continue to heat with 60% to 80% efficient boilers and even old mammoth type boilers which have been converted from coal to oil to gas at 45 to 50% efficiencies. Some very old systems continue to heat with very wasteful steam heating. All these inefficiencies are opening many more opportunities to save energy and increase comfort. Newer boilers feature benefits such as Modulation and Hot Water Reset and Intelligent Igniter Control. Controls and pumps have high tech features with outdoor reset and variable speed which are incredibly accurate.

Whether your needs are for a replacement hot water or steam boiler or a hot water baseboard system, radiant floor heating system, snow melt radiant system or hydronic forced air system, we can provide a complete system with all components. DESCO Energy is the only online source capable of providing hot water high efficiency condensing boiler systems with the manufacturer's approval, warranty and in-house certified factory trained technical support. There is no other online source that is approved or endorsed by any boiler manufacturer for warranties or technical support nor are their sales approved by the boiler manufacturer they represent. DESCO Energy will never knowingly sell any boiler to any homeowner who has no intention of following SEER - Solutions for Energy Efficient Results and the guidelines and requirements including the use of a licensed installer of your choice to provide final start up and check out of the boiler and complete the warranty validation form. SEER and the warranty validation form are exclusive to DESCO Energy and are created in cooperation with the manufacturer, industry standards and our 34 years experience of providing thousands of successful do it yourself heating and air conditioning systems. 


DESCO Energy will put together a complete package for your specific application including an energy efficient In Floor Radiant Heating System. Only here can you find a complete package including the air handling systems and hydronic systems designed and selected for your specific needs. Radiant Floor Heating provides many energy savings and comfort features which surpass all other forms of heating. We like to refer to floor radiant heating systems as Decorating with Comfort. Features and benefits of radiant heating are quiet operation, maximum comfort, individual room control and maximum energy efficiency. Only slightly more expensive than a forced air heating system radiant heating is all about comfort. .


Whether your needs are for your home, business or industrial applications DESCO Energy can provide the best system for you at wholesale pricing. And we'll show you how your new system may be eligible for Tax Credits under the New Energy Bill.


On January 23, 2006 all HVAC manufacturers have been mandated to only produce air conditioning systems with a minimum 13 Seer or Seasonal Energy Efficiency Ratio. Heat Pumps are also mandated for the same air conditioning efficiency with a minimum 7.7 HSPF or Heating Seasonal Performance Factor. 13 Seer line will be the lowest grade equipment produced with the lesser of all warranties. The 2006 Energy Tax Bill will offer tax credit rebates effective for equipment installed on or after January 1, 2006. A $300 rebate will be offered for split system air conditioning systems of 15+ Seer or packaged systems with 14 Seer. There are also tax credit rebates of $50 for variable speed blower motors. Heat pumps with the same 15 Seer air conditioning and 9.0 HSPF are also eligible for a $300 rebate. Gas or oil furnaces and boilers with 95% AFUE efficiencies or higher are eligible for $150 Tax Credits. Total tax credits for a single home up to $500 are available for a wide variety of energy improvements. For more details see The Energy Star website.


Other sellers online have no guidelines or requirements other than copies of the manufacturers specifications. Because of SEER - Solutions for Energy Efficient Results - the guidelines and requirements established are in cooperation with the manufacturers we represent, industry standards and our 34 years experience assisting business and homeowner do it yourselfers. DESCO Energy is the only online HVAC Distributor able to offer you a complete hydronic heating system which meets and exceeds the manufacturers requirements and approved by the manufacturer. Please note DESCO Energy will never knowingly sell any boiler or HVAC system to any homeowner who has no intention of following the guidelines and requirements we have established including requiring a licensed technician of your choice provide start up and final set up of any boiler and complete the warranty validation form provided by DESCO Energy. For further information about the guidelines and requirements of SEER read about Warranties in our Getting Started Section.

Below are the items required when installing a boiler. The first item in a gas boiler is the size required. Gas boilers are identified as capacity input and oil furnaces are identified for capacity output. A gas boiler at 100,000 btus can have various heating outputs from 75,000 btus to 95,000 btus depending on the efficiency. It is extremely important to size any furnace on capacity output as this is the amount of heat the boiler produces to the house. The input rating is irrelevant when selecting the proper size furnace. Boiler capacity ranges are identified from 45kto 200k btus input for residential applications. It is extremely important to select the boiler not on this size but the output capacity. For example if your heating load as determined by our online Manual J sizing is determined to be 80k btus a boiler of 100k btus input of 100k btus and 80% AFUE will provide 80k btu output and be a perfect selection. But if you want higher efficiency then a 90k boiler at 90k btus input and 95% efficiency will have 85.5k btus output capacity. You can see that the old gas boiler identification by input heat rating was fine when all boilers were of the same efficiency. But this antiquated identification system needs to be discarded for the wide varieties of heating efficiencies available today. SEER - Solutions for Energy Efficient Results recommends that no boiler less than 90% efficiency should be used in any application today. 80% AFUE cast iron or steel boilers require expensive chimneys and waste 20% of the energy supplied up the chimney. 80% boilers have more warranty, maintenance and service problems than the newer hi efficiency condensing boilers because they're not made as well.

The vast majority of gas boilers today require a closed combustion system. Most technicians and homeowners mistakenly believe fresh air intake requirements are an energy efficiency feature. However it is required for protection of the heat exchanger, not energy efficiency. A closed combustion system requires both fresh air intake and discharge through pvc or a chimney to protect the furnace. Boilers many times are located in laundry rooms or in closed basements. Volatile emissions form fabric softener pads or soaps and chlorine bleaches will quickly destroy a heat exchanger when these product fumes come in contact with the combustion flame. To protect the heat exchanger from these types of volatiles including nail polish remover, spray paints or other normal household cleaning agents maximum heat exchanger life is obtained when the air for combustion is taken from outside. Heat exchanger failures caused by volatiles capable of destroying stainless steel heat exchangers are not covered under any manufacturer's warranty. Further there are some home remedies for treating arthritis and other afflictions using chemicals such as DSM which is a dry cleaning fluid. When this chemical comes into contact with a flame it will permeate the metal of the heat exchanger causing a foul rotten egg like odor every time the flame is ignited. The only means of removing the odor is to replace the heat exchanger because it is embedded into the metal. To be safe always use a closed combustion system to protect your new boiler.

When installing your new boiler with a closed combustion system you will need to make two separate wall penetrations for intake and exhaust air. Using the concentric vent kit eliminates the need for two hole penetrations allowing only one hole penetration, creating a more appealing professional appearance. 


While some homeowners may find the cost of installing a concentric vent kit out of their budget the two holes can be made for a closed combustion system and then dressed up with a less expensive decorative vent termination kit. In either option both the concentric vent kit or wall termination kit are substantially more appealing and create a very professional attractive appearance. Nothing looks worse than plastic tubes with various elbow configurations extruding through exterior walls of your home.


The thermostat is the next item required. Thermostats come with many different features and programs today. The newest hi tech thermostats provide a wide array of energy saving features such as every day of the year programming with daylight savings features to monitoring hours of operation with reminders for when to change filters. By slowly raising temperatures at different time periods depending on time required, intelligent energy management will raise indoor temperatures according to the recovery time required.  In addition they can also control humidity for humidification while monitoring outside air conditions to prevent condensation of walls and windows. Some thermostats can actually control both radiant heating systems and forced air systems combined or for floor warming systems in conjunction with forced air or heat exchange recovery systems. Some thermostats are internet ready where they can also be monitored or adjusted over the internet or phone or monitor conditions to send alarms. All this with many more functions or to the simplest electro mechanical thermostats are available.

There are many different methods of controlling multiple zone systems in baseboard or radiant heating systems. There are hi tech controllers available to provide energy saving and precise temperature control as well as preventative maintenance features. For short cycle operation of pumps to prevent lock up during the course of any time period or to control variable speed pumps and water injection or thermostats and floor sensors with outdoor sensing combined. The cost of many of these features are a small investment in the overall project but the comfort and energy savings benefits are incredible. DESCO Energy will design the best comfort control system for you based on your requirements.

In every type of application where the boiler is elevated above the radiant or baseboard heat or where piping is below the boiler a low water cutoff is required to protect in the event of a leak or loss of water. 

Electrical thermostat wire needs to be considered for wiring from the thermostat to the indoor air handler or furnace and then to the outdoor condensing unit. Remember thermostat wiring should never be installed inside conduit or plastic sheathing with power wiring. The new hi tech thermostats can require up to 8 conductors from the thermostat to the air handler or furnace while thermostat wiring from the indoor furnace to the outdoor unit will generally require no more than 3 conductors. When running thermostat wire make certain to always run one or two more leads than required for future changes or a broken wire that may occur. 

All condensing gas boilers produce water and need to be drained to a sewer line. When a drain access is not readily available such as in a basement or first floor application the use of a condensate pump may be required. Condensate from gas furnaces is drained into the pump reservoir where a float energizes operation of the pump. The water can then be pumped to a local sewer line. Alarm contacts are also provided to deenergize the air conditioning system in the event of pump failure. 3/8" clear plastic tubing is then piped outside or to a local sewer drain. Never drain or pump water from a gas furnace outside as the acid in the water will destroy all vegetation.

For customers using propane gas you will require a propane conversion for standard cast iron and steel gas boilers. For standard gas boilers this conversion is a

simple change of gas orifices. DESCO Energy will provide the propane conversion for you when requested at a nominal cost. For the high efficiency Trinity and Takagi boilers there is no need for an extra conversion accessory as these boilers ship with propane conversions as part of the system. We do however advise all customers considering the use of propane gas to reconsider their energy usage. In most parts of the country excluding California the cost of propane gas is more expensive than electric resistance heating. In fact in many parts propane costs 50 to 100% more than electric heat. Ask your technical associate at DESCO Energy about less costly forms of heating.

The first item required in a new or replacement boiler system is the fill valve. The purpose of the fill valve is to maintain a water supply with a constant pressure. The pressure setting of the fill valve is to offset the natural gravitational force of the water in the system as determined by the highest point of piping. A hot water system uses a circulation pump that is not designed to overcome the force required to work against the natural weight of the water. The circulator pump is to circulate the water and to move this water in a closed loop and create flow with the only resistance being that of the piping system. There is another force in a water system due to the height of the piping from the lowest point to the highest point. The gravitational weight of the water produces one pound of pressure for every 2.3 feet of height. In a two story house with a boiler located in the basement the average height from the lowest point at the boiler to the highest point of the tubing to the second floor is 20 feet. That's equivalent to 8.7 pounds of pressure. If we were to take a 20 foot pipe of any size diameter and fill it with water and place the pipe in a vertical position the pressure created by the water from gravitational pull will produce 8.7 pounds of pressure as read at the bottom of the tube. So to eliminate the force of the gravitational force it is necessary to statically charge the entire system a minimum of 2 to 3 pounds higher than the gravitational force of the water as determined by the total height of the piping. Water fill valves are preset for 12 to 15 psi of pressure which is satisfactory for a height of up to 30 feet. Pressurizing the system provides proper flow of water throughout the system by the pumps. Insufficient pressure will result in low or no flow on the upper levels of the heating system. Also pressurization assists in pushing unwanted air out of the system tot he highest points. As air is pushed out of the system or eliminated due to automatic air bleeds a constant supply of pressurized water is always necessary. Fill valves are also rated in how rapidly they can fill a system. Typically the fill valves supplied will be quick fill where maximum flow can be achieved through the valve. It is also important to provide a bypass loop around the fill valve for quick filling after repairs or initial installation is complete or for failure of the valve. The maximum pressure of any system cannot exceed the boiler and relief valve pressure settings. Excessive water pressure will result in a hazardous condition and cause the relief valve to open to reduce system pressure. Causes of excessive water pressure are too high a setting on the fill valve, a faulty water feed valve which leaks by or an expansion tank which is either defective, full of water or undersized. Steam heating systems require a water fill system that operates differently via either a water solenoid and internal water flow sensor. Steam systems only maintain a water level. 

Standard boilers come equipped with circulation pumps already installed. Wall hung boilers require circulation pumps to be installed additionally. High efficiency condensing boilers require a primary and secondary loop with separate pumps for each loop. The primary pump is strictly for the circulating of water through the boiler and has high head pressure and flow capabilities to overcome the resistance of the boiler. In radiant heating systems and baseboard heating systems several pumps will be used for ach zone. Pumps are a far superior method to controlling zone flow rather than zone valves. Pumps and valves are about the same cost but valves last longer and keep flows consistent. Using one pump with several zone valves will result in varied flows and overshooting of temperatures. Variable speed pumps are available to control water temperature in multi function systems using different types of applications such as baseboard heat combined with radiant heat. To control the temperature of the lower water required for the radiant system from the same boiler a variable speed pump can be employed allowing injection of hot water into the loop. Pumps will almost always require flow check valves to prevent convective heat flow when the pump is not in operation. A heating system having several zone pumps will convect water flow in the zone that has no flow check valve creating unwanted overheating. Pumps can be provided with internal flow check valves and are identified by FC in the identification. It is recommended to always use pumps with internal flow check valves internally provided when required. Pumps typically are provided without flanges. Flanges are required and can be supplied with shut off valves built into the flanges. Much easier to install flanges with built in shut off ball valves provide an easy quick method of future pump replacement and service.

All hot water systems with multiple zones or pumps will create water flow sufficient to cause overheating if there is no flow check valve installed. In multiple zone systems any pump operating will cause the boiler to operate or if the system is set up to maintain a constant water temperature on a continuous basis water will flow due tot he difference in temperature called convective water flow. A flow check valve is designed to open as a result of the flow by a pump but remains closed preventing water flow by convection. Older systems did not use pumps and relied on convective water flow to heat the entire house. But today's systems will cause overheating if convective flow is allowed. As described above in pumps a flow check valve can be incorporated into the pump but can also be added separately. 

All hydronic systems need an expansion tank to absorb the expansion and contraction of the water as the temperatures of the water change. The size of the expansion tank is determined by the quantity of water in the system and the size of the boiler in capacity. Older systems use expansion tanks which are simply metal tanks where the water comes in direct contact with the air. The problem with metal expansion tanks is that in several months the water will absorb the air rendering the effectiveness of the expansion tank useless. The system than builds up excessive pressure causing the relief valve to lift. The only remedy is to drain down the expansion tank on a regular basis to introduce fresh air into the expansion tank. The metal tanks sometimes were equipped with sight glasses to monitor the water and air levels. New expansion tanks use a rubber bladder which isolates the water from the air. On the air side the bladder can be inflated to maintain system pressure. The access port for air also permits the expansion tank to be checked for proper pressure or any faults such as the bladder rupturing. Bladder type expansion tanks require less space and last a lifetime if the bladder doesn't rupture.

Air scoop is required in every boiler installation to separate the air out of the system at the main loop. As water passes through the air scoop it is separated by means of baffles in the air scoop and transferring the problem air up and out to an air eliminator. Water constantly looks for oxygen and air and it will absorb as much as possible whenever the opportunity exists. Removing and keeping air out of the system and out of contact with the water will significantly reduce problems associated with it. Air entrapped in a closed water system will release and trap in areas where it is usually the most difficult to remove. Entrapped air results in reduced or no water flow.

Air eliminators are of two basic types which are manual and automatic. Manual air valves are simply opened when the system is serviced or air is entrapped in that particular area. Automatic air vents will remove the water automatically by sensing the air and relieving it to the atmosphere. It is recommended automatic air vents be installed in the highest points of the system. Also eliminators should also be installed in parts of the system where air may be entrapped and it's removal would become difficult to remove. Air eliminators are a very small investment and they should be used abundantly. In most applications there is a severe lack of air eliminators resulting in poor or no water flow. It can take a tremendous amount of time resulting in an equal amount of frustration trying to remove air entrapped when there aren't sufficient eliminators. Attaching a hose to the system using full flow in reverse sometimes may be required to attempt to remove entrapped air. If the system has to be serviced in such a manner to remove air install an air eliminator so the procedure isn't required again. Air can take a long time to accumulate in an area to affect flow and usually the problem doesn't become apparent until the coldest of weather. Save yourself this trouble and frustration by having sufficient air eliminators not only at the highest point but at various points in the system where isolation can occur.

Relief valves are required on all boilers and must be installed directly on the boiler. Relief valves are sized according to the capacity of the boiler in btus and the pressure rating of the boiler which is almost always 30 psi. Relief valves should be checked annually for opening and seating.

To produce hot water for domestic applications it is best to use an indirect water heater in most applications rather than an auxiliary coil that is inserted in standard boilers. The inefficiency of hot water coils in cast iron boilers and the small amount of water that can be produced make producing hot water inefficient and insufficient. An indirect water heater which uses a heat exchanger inside the water tank. Hot water generated by the boiler is the most effective method of providing consistent efficient domestic hot water at sufficient capacities for most applications.

Pex tubing used for in floor radiant applications and also as a connector tubing for baseboard heating and domestic water systems. Loops should be kept to within no more than 260 feet at 5/8". All tubing supplied by DESCO Energy is manufactured by Zurn and has the oxygen barrier. Oxygen inhibited tubing inhibits the oxygen passing through the tubing to the water. Water in a closed loop heating system has an affinity for oxygen and will absorb high amounts of oxygen from any source possible. Incredible as this may seem oxygen can pass through Pex tubing without the oxygen barrier. Because oxygen is such a small molecule and will pass through the Pex material under normal usage. How water systems not using oxygen barriers will se a short term failure of the pumps with in a year. As well other components of the system will be attacked. High efficiency boilers can be destroyed quickly when exposed to heavy concentrations of oxygen in the water. HVAC manufacturers do not provide warranty support for any failure resulting from destruction caused by oxygenated water. Oxygenated water is highly corrosive and quickly destroys all forms of steel and eventually copper and brass prematurely destroying components in the system. For the small difference in cost it is strongly recommended to use Pex tubing with oxygen barrier protection. DESCO Energy excludes warranties on all products installed on hot water heating systems using Pex tubing without the protective oxygen barrier. Pex tubing is sold in 300, 500 and 1000 foot lengths.

For underfloor applications of radiant heat systems radiant transfer plates are required. Heat Transfer Plate
                        Provides enhanced heat transfer from ZurnPEX (Oxygen Barrier) tubing to underside of wood subfloor.
                        Plates measure 5"x 20".Leave 3"-6" gap between plates.


Radiant heating systems require manifolds as a central connection source. The manifold is where flow, temperature and entrapped air can be checked. Each loop can be balanced for correct flow and troubleshooting can occur when the need arises. Each loop can be a zone off the manifold by the addition of valves or the manifold can be a single zone. Manifolds can be located in walls behind access doors in closets or directly with in living areas inconspicuously. 

Baseboard heating sections are available in various lengths and capacity outputs. Baseboard heating sections are selected on the basis of heat requirements per each room. They are typically applied to exterior walls but can also be added to interior walls when there is insufficient exterior wall length. Baseboard heating sections are available to provide 310 btus to 890 btus per linear heat output. Output capacity is determined by type of baseboard section, water temperature and flow rate. We recommend relying on DESCO Energy to select and size the correct baseboard heating sections required for your house. Each length of baseboard is fully assembled, ready for box-to-wall installation.

Hydronic air handlers with hot water coils and self contained pumps for forced air heating are available. Also included in the air handlers are air conditioning coils. Sizes available from 1.5 to 3 tons of cooling and heating capacities from 18,400 btus to 71,000 btus. For specialized applications custom made hot water coils can be supplied for any type of forced air system.



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