High-efficiency boilers. Displays that translate error codes into plain English. Adapters that let technicians skip the flames and heavy welding equipment — and, in some cases, the extra burden of the fire department standing over their shoulders.

Hydronics manufacturers have been focused on making the world of hydronic heating more efficient for contractors and for end users alike.

Here’s a look at some of the newer products to hit the the market in the realm of hydronic heating.



When it comes to piping, Uponor’s newly launched ProPEX copper press adapters say “don’t sweat it” — pun intended.

“As PEX piping becomes more prevalent in commercial plumbing projects, design and installation professionals told us they needed a solution to quickly and confidently connect hybrid plumbing and hydronic piping systems,” said Doug Fulton, senior director, corporate strategy and segment marketing at Uponor.

Using Uponor ProPEX LF Brass Copper Press Adapters and the M18 ProPEX Expansion Tool from Milwaukee Tools, technicians can create a PEX-to-copper transition without the use of flame, glues, or solvents. The adapters connect ASTM F1960 PEX expansion connections to ½-inch to 3-inch copper press piping systems.

“Once you get into those 2½-inch and 3-inch sizes, pressing copper makes a lot more sense than sweating copper or brazing copper, like a lot of people used to do,” said Daniel Worm, manager, Commercial Marketing Segment, Uponor.

Also, there’s a big push toward getting flames and hot-work off of job sites, he said — especially on older wood-frame buildings where re-pipe work is required. Instead, a connection is created by putting a ProPEX ring on the outside of a PEX-A pipe, expanding the pipe, and fitting the two ends together. The pipe then contracts back down on the fitting, and it can be pressure tested shortly after it’s done.

Manufactured from lead-free brass to meet all local and national potable-plumbing codes, the press adapters reduce overall project timelines by an average of 71 percent compared to sweat, according to Uponor. The product also incorporates a patented design for securely fastening the pipe and fitting together, eliminating the need for a stainless steel ring.


Designed for Iron Pipe Size (IPS) stainless steel, Viega’s new line of MegaPress Stainless XL fittings allow for secure connections in 2½-inch, 3-inch, and 4-inch pipe.

“Since Viega introduced MegaPress Stainless fittings in 2017, customers have been asking for them in larger sizes,” said Dominic Küng, Viega product manager for Metals.

MegaPress fittings reduce installation time by up to 90 percent, compared to traditional pipe joining methods, he said.

“Within two minutes, you’ve done a whole 4-inch T, whereas a good welder would probably take somewhere in the neighborhood of two hours,” he said. “With the lack of skilled labor, this is a great way to be able to bring somebody in, let them help contribute to the business while learning to weld or braze or solder on the side.”

Not having to spark a torch also means no hot-work permits and no fire watches, which are required in some cities. In Boston, for example, contractors doing hot-work are required to have a firefighter personally oversee the work to make sure nothing catches fire.

MegaPress Stainless XL fittings are available in 304 and 316 stainless steel and are approved for use with Schedule 10 to Schedule 40 pipe. They are equipped with patented Viega Smart Connect technology, which allows installers to identify unpressed connections during pressure testing.


Weil-McLain’s most advanced commercial stainless steel boiler, the new Stainless Steel Vertical Firetube (SVF), features thermal efficiency up to 97.1 percent, serviceability features, and the Unity control system.

Available in 750 and 1100 models, the SVF line features a clover-shaped stainless steel fire tube heat exchanger for corrosion resistance, a new exterior look, and simple controls to make installation and operation easy. Its cost savings and energy efficiencies allow owners to qualify for local utility rebates, if available.

The unit meets all market-driven bid specifications, and is designed for heating needs including schools, public institutions, health care buildings, offices, hotels, multifamily units, and churches.

For ease of service, the SVF features a hinged cover plate, allowing quick access to the burner and fire tubes for simple heat exchanger wash-down with no need for additional disassembly, and an open back panel design with no side access required for service. The unit also has a removable and replaceable condensate base.

Time-saving installation features include heavy-duty roller casters for improved maneuverability in confined spaces, industrial-grade leveling legs, an end-shot burner design requiring only 18 inches overhead space, and the advanced Unity control setup wizard.

“The Unity controller is designed to reduce installation and set up time for contractors, simplify boiler system design for specifying engineers, and improve control interface commonality and communication across the entire Weil-McLain high-efficiency boiler line,” said John Miller, senior product manager.


With its compact design, Rheem Mfg. Co’s Energy Star® certified Professional Prestige Combination Boiler can free up space in smaller homes or multifamily applications.

“Our new Professional Prestige Combi Boiler combines two essential appliances with one cost-saving solution — and no sacrifices,” said Stacey Scott, tankless marketing manager. “Designed to perform at the industry’s highest efficiency levels, the Combi Boiler provides homeowners with reliable space heating and continuous hot water at reduced utility costs while occupying a smaller footprint.”

At 95 percent AFUE, the Combi Boiler is over 15 percent more efficient than the company’s standard model. The higher efficiency is a result of its ability to extract more heat from the unit’s exhaust gases, which makes it eligible for local rebates, too.

Additionally, the design allows for the use of PVC venting options, which increases flexibility for easy installations and reduced labor costs.

Other features include the Outdoor Reset Sensor, which senses outdoor temperatures and adjusts the boiler accordingly. When combined with the built-in Auto Boost Feature, the boiler will automatically boost the hydronic loop to reach the desired temperature faster.


Navien’s new NFC series stainless steel fire tube combi-boilers, available in two sizes — NFC-175 (175,000 Btuh) and NFC-200 (199,900 Btuh) — provide enough heating input for up to a 3,500-square-foot home and continuous domestic hot water supply for up to three bathrooms.

“With our NFC product, we’re going with the concept of a boiler in a box,” said Eric Ashley, product development manager. “You can replace a cast-iron boiler and provide the equivalent of a stand-alone tankless unit, all in one package.”

Every unit comes with a NaviClean filtration system, designed to remove iron oxides and metal particulates commonly found in heating systems, as the majority are replacements for cast-iron boilers. Other features include 95 percent AFUE for energy savings, 11:1 turndown ratio for wide operating range without cycling, common venting capability up to eight units, cascading capability up to 16 units, and built-in hardware to connect up to three zone pumps without a need for additional external controllers.

All NFC series units include a primary loop manifold that consists of a stainless steel header and 1-inch isolation valves in the box.

“Basically, it has a complete primary loop in the box, so the contractor doesn’t have to think about building something on-site,” Ashley said.

Front panels are now in plain English style display instead of codes.

“It will walk you through setting it up,” said Ashley. “It makes it a lot easier for a contractor to set up, instead of wondering ‘What’s an E03?’”


The new Bosch Hydronic Air Handler can replace ducted furnace systems, eliminating the need for a gas pipe, venting, and fresh air intake required for furnaces. When used with a tankless water heater, it produces both efficient heat and domestic hot water. The system is managed by an integrated control board that connects to the home’s thermostat.

“The pumps and controls are built on board the unit, making it a simple, plug-and-play installation,” said Dan Moffroid, product manager. “Many American homes combine their furnace with an air conditioning system, so Bosch designed its hydronic air handler to be the same dimensions as more furnaces to fit the a/c unit to go on top.”

The air handler connects seamlessly with tankless water heaters, transferring the unit’s hot water through a hydronic heating coil. As hot water circulates through the pipe, warm air is sent through the residential duct system. The cool water in the hydronic coil then recirculates to the tankless unit to be reheated.

Two models — AHU 50 and AHU 70 — can be sized with most cfm and Btu output ratings to suit most typical-sized homes. When the thermostat calls for heat, the air handler activates the integrated pump, turning on the fan 30 seconds later. After the thermostat is satisfied, the blower runs an additional 30 seconds to deliver conditioned air. When the thermostat calls for cooling, the control board activates only the blower.


Publication date: 5/13/2019

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