ProStaff Review—Cross Manifold System: The Evolution of Hydronic Distribution

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Eric Aune, Aune Plumbing LLC, Zimmerman, Minn.




Dan Foley, Foley Mechanical Inc., Lorton, Va.



Andy Mickelson, Mickelson Plumbing and Heating LLC, Missoula, Mont.



The Cross Manifolds with two primary zones: a garage and a partially finished basement.

From across the PHCC Connect trade show floor, a new product offering recently caught the eye of our ProStaff team members. “I like to walk trade shows as I need to physically see a new product before I can evaluate it. I need to touch it, pick it up, and examine it before I make a purchasing decision,” says Dan Foley.

The sparkle in Foley’s eye was the new Cross Manifold system, which combines a zone relay, manifold and zone valves in one compact, pre-wired package. “Any product that saves space, man-hours on the job site, and minimizes wiring gets my attention,” says Foley, whose company specialty is hydronic and radiant systems installations.

Big Sky Zoning

From almost entirely across the country, ProStaffer Andy Mickelson recently installed the Cross Manifold system on a job near Missoula, Mont. The Cross Manifolds were installed in a radiant floor system with two primary zones: a garage and a partially finished basement.

The project called for a simple electric boiler with one circulator feeding the two radiant manifolds. After receiving the manifolds, Mickelson was immediately intrigued with the packaging. Cross Manifold comes in what appears to be a plain cardboard box. On the inside is a well laid out divider that separates the smaller components from the manifold. The parts compartment features basic instructions, a plug-in 24 VAC transformer, the zone control, a pair of 1” NPT isolation valves with thermometers, drain and purge valves and a couple of spare O-rings.

Beyond the small parts divider is the manifold and actuator module. The manifolds come in 4-port thru 12-port configurations, with or without flow meter balancing valve assemblies. Mickelson ordered a 4-port and 6-port for our project, both with flow meter assemblies. When ordering the manifolds there is the option for 1/2” or 3/4” crimp PEX or 1/2” or 3/4” press–sweat adapters.

Installation of the manifold was a simple process, says Mickelson, who used 1/2” PEX adapters on the installation. “I have installed a number of manifolds that had poor threads on the adapter ports or on the isolation valve ports; this is not that type of manifold. Everything went together finger tight, at which time we then bumped them up with an end wrench. I was most impressed with the fit and finish of the sealing surface—not a single leak at the manifold,” says Mickelson.

Mickelson’s only complaint or suggestion was that he could not find anywhere in the manual where it indicated flow direction. It took playing with the flow indicator to figure out which was supply and which was return. The actuator module is attached with two thumb screws, one on each end. Something worth noting: All of the ports on the manifolds come with caps; the adapters are shipped loose. The advantage here is that any unused ports are already capped, no need to purchase additional components.

With all of the piping complete and the actuator mounted, we moved on to the wiring, continues Mickelson. The 24 VAC power supply is attached to the zone control module with two conductors. The thermostats are connected to the zone inputs along the bottom, which include “R”, “W” and “C” terminals. The “C” terminal being important these days, as nearly all Wi-Fi stats require a “C” terminal to operate the Wi-Fi radio properly.

The power draw on this manifold is quite low as the design allows only one circuit to be opening or closing at a time. In Mickelson’s installation, they had one thermostat controlling each manifold, so the circuits that we used had to have the “W” terminals jumped. The “SW Out” terminals provide a dry contact closure to initiate a call for heat to a boiler or other control. The control board also includes a 24 VAC output to operate pump relays or other pilot duty loads. This board has a 1.5 amp fuse holder built in.

“I would like to see an additional fuse included, as accidents do happen,” says Mickelson. The zone control does need to be mounted relatively close to the actuator module, as the two are connected with a Molex plug wiring harness. The harness is roughly 18” long.

Capitol Manifolds

Back in D.C., Foley had an 8-zone radiant heating project he needed to pipe and wire. Typically Foley would have piped a copper manifold, installed eight zone valves, and wired in two 4-zone relay panels. With the Cross Manifold System, the eight zones come pre-piped and pre-wired. The stainless steel manifold assembly is simply bolted to the wall and piped to the boiler. The radiant zones are tied in and the thermostats connected to the terminal strip. The zone valves are already wired.

Installation of the Cross Manifold from Foley Mechanical.

“The system was installed and started this past January. “Running nearly four months now, the system has performed flawlessly,” says Foley.

Foley had only one issue with the Cross Manifold, but it was self-inflicted: the installer over-tightened one of the connections causing it to crack. The instructions were clear: hand tight is sufficient. “Cross was kind enough to overnight a replacement fitting and we had it repaired the next day. Technical support was responsive and knowledgeable,” says Foley.

To the north, Minnesota’s Eric Aune installed a Cross system recently and offers some assembly and installation tips.

Unpacking and assembly:

  • One box contains everything needed for the install.
  • The instructions are simple illustrations, and if one has never used one of the manifolds, it can be a bit confusing for first-time users.
  • In the event that any of the loop connections are not needed on the model you order, it is shipped with plugs on every outlet.
  • The manifold is shipped with every outlet connection plugged; tubing adaptor fittings are included in the box.
  • If you order flow meters, those will have to be assembled onto the manifold as well, removing the stainless plugs in their place for assembly.
  • The whole kit includes the manifold, tubing adaptor fittings, motorized control box, zone control module and power supply cord.

Installation on the wall:

  • This manifold sticks out from the wall more than other manifolds on the market, so if it has to be concealed in a stud cavity, you’re not going to do that without a 2 x 8 at least, this needs to be known ahead of time.”
  • The manifold brackets are like all other standard brackets and position the manifolds offset from each other and from the wall.
  • Since the loop actuators are actually ball valves installed on every outlet there is no additional valve actuator to assemble onto the manifold; the motor carriage simply bolts onto the front of the manifold and connects to the zone control module.
  • The motor carriage connects to the control module with a prewired molex-type plug. “I would prefer this was about a foot longer because it requires the module to be placed rather close to the manifold but it makes for very easy and fast wiring, eliminating the need to spend an hour or two wiring each zone individually,” says Aune. This also eliminates the need to have control wiring in stock for this task.
  • The quality of the stainless steel threaded connections seems better than some others Aune has worked with in the past. Rubber gasket connections on these types of manifold often leak upon initial fill requiring adjustments and time; the Cross manifold had zero leaks on fill and startup.
  • Each individual ball valve on the loops is made from an engineered plastic that moves very freely and gives the first impression of excellent molding and fitment. “These are serviceable/replaceable parts, I will be ordering a few replacements to keep on the truck,” says Aune.

Overall Impressions

“Overall, I would say the time saved by not having to wire individual zone actuators is noteworthy,” says Aune. Although the product is well designed, continues Aune, some improvements to the information and ordering experience on the website could be made to speed that process up and increase confidence that you’re in fact ordering exactly what you need the first time.

“Of course, as you install more of these, that will be less of a factor,” says Aune. “I have one manifold in operation at this time and have already considered using more for either replacement or new installation as I am overall impressed with its performance.”

Foley see several advantages to the Cross Manifold system. No. 1: It’s a time saver—it saved time vs. field fabricating and field wiring. No. 2: Neatness and uniformity: The compact manifold saves wall space and looks professional. It also eliminates the variation of field technicians piping and wiring jobs differently. No. 3: Pre-wired—Low voltage wiring can be a challenge at times. This system is pre-wired from the factory minimizing wiring issues.

“I give the Cross Manifold two thumbs up and intend to use it on future projects,” says Foley.

Overall, Mickelson was very impressed at how quickly the manifold was mounted, piped and wired. “If we had been using multiple thermostats on each manifold it would have been exponentially quicker than wiring up tele-stats and zone control boxes. Once we got the boiler mounted and filled, start-up was a breeze, only requiring us to balance each circuit with the flow meter balancing valve,” says Mickelson.

The actuator is incredibly quiet during its operation, which only takes a few moments to open all of the valves. Once the operation is complete, the actuator module is at rest until the valves need to be closed. Interestingly, the actuator module actively monitors the valves to ensure that they are not moved out of position. If a valve for some reason is incorrect or manually moved, the module will correct that condition accordingly.

“Overall I am impressed with the installation, operation and quality of the manifolds,” says Mickelson. “I look forward to adding these manifolds to our arsenal of products to offer to our customers.”

For more information on the Cross Manifold System,

Cross Manifolds are available through plumbing & heating wholesale distributors nationwide.

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