Large NRG Zone 5 & 6 – 1 1/4″ Side Ports


520.00570.00 ex. VAT

The Larger NRG ZONE 32/32/28 patented manifold is used at the centre of any central heating system and allows for rapid system construction, total flexibility, complete reliability and ultimate cost-effectiveness in both system’s running costs and installation in any new-build or retrofit central heating project.

  • Description
  • Additional information
  • Specifications
  • Technical Documents


The NRG ZONE is one of the most innovative products to appear in the heating sector for many years. At first glance the unit looks like many other manifold type products that already exist in the marketplace and may seem to act simply as a form of extended “low loss header” but that is certainly not the case.

The patented design builds upon well proven and effective design methodologies from the heating industry. It improves system efficiencies, reliability, safety as well as reducing installation cost and saving space.

One of the main features of the NRG ZONE is the three-chamber design. This design ensures that the flow of each zone is the hottest water possible. It also ensures the heating appliances operate under the best conditions possible, thereby improving their efficiencies and reducing running costs.

Conventional Boilers and Solid Fuel Stoves

High-temperature boilers or solid fuel stoves are not designed to have very cold return water. If the return water is too cold acidic condensation might develop inside the heating appliance and corrode it. With the NRG ZONE, these appliances will take their return water from the bypass chamber. The water in the bypass chamber is a mix of the water in the return and flow chambers, and is therefore warm enough to prevent corrosion in the heating appliances while still being cold enough to let the appliances perform efficiently.

Condensing Boilers

Condensing boilers are very good boilers with efficiencies far above the conventional boilers. For the condensing boilers to achieve such high efficiencies they extract heat from the flue gasses through condensation, hence the name. For this to be possible the return water going into the boiler should be below 55°C. With the NRG ZONE, the condensing boilers can take their return water from the return chamber. Since all the zones feed their return water directly into this chamber it contains the coldest possible water in the system. This greatly increases the possibility of condensing and optimizes the amount of time the boiler spends in condensing mode.

Heat Pumps

Heat pumps operate at much lower temperatures than boilers and stoves. They also require low-temperature return water to achieve the best efficiencies possible. As explained in the section above, the NRG ZONE ensures that the heat pump will get the coldest possible return water. The NRG ZONE also makes it easy to combine heat pumps with other high-temperature appliances. The more energy efficient heat pump can preheat the water and deposit it into the bypass chamber. Then a less efficient high-temperature boiler can take the water from the bypass chamber and heat it up to the desired temperature before depositing it into the flow chamber.

Full System Bypass and Air Separation

The NRG ZONE manifold has a full unobstructed system bypass. This guarantees that each zone and heating appliance circuit can work independently of each other as well as together. The pumps in the different circuits won’t pushpull on other circuits. Another benefit of the NRG ZONE is that it includes air separation. Inside the manifold, there are built-in air collection mechanisms. They gather all the air in the system at one point directly below a socket where an automatic air vent can be attached. The air separation point is located at the point in the system with the highest temperature, and lowest pressure and velocity, all complying with best practices. Air separation is important to prevent air locks and corrosion in the system as well as maintaining the water’s heat capacity and system effectiveness.

Different sizes

The NRG ZONE 32/32/28 comes in two different sizes: the  NRG ZONE 5 and NRG ZONE 6. Each manifold has three 1 1/4” sockets on each side, one for each chamber; this is where the heating appliance is typically connected. On the top there are three 1” sockets; where one is for the air separation and the other two can be used for zones, appliances, sensors and cold feed. The only difference between the two manifolds is the numbers of pipes underneath. The NRG ZONE 5 has 6 1” pipes, 3 flows and 3 returns. The NRG ZONE 6 has 8 1” pipes, 4 flows and 4 returns. All the manifolds are fully insulated to limit any heat losses.

The standard NRG ZONE 28/28/28 provides all the same benefits as the 32/32/28, but with smaller side ports (1 (28mm) female iron fittings instead of 1 1/4″ (32mm)). These units will cover most domestic heating systems and are less costly than the NRG Zone 32/32/28.

If you are a tradesman please contact us for trade discount on this product.

Download Installation Manual:

Additional information


NRG ZONE 5 32/32/28, NRG ZONE 6 32/32/28


  NRG Zone 4 32/32/28 NRG Zone 5 32/32/28
Length [mm] 375 525
Width [mm] 150 150
Height [mm] 320 320
Material Mild Steel Mild Steel
Number of direct zones 2 3
Connections 3×1″ female iron fittings
6x 1¼” female iron fittings
4x 1″ female iron fittings
3x 1″ female iron fittings
6x 1¼” female iron fittings
6x 1″ female iron fittings
Threads BSP BSP
Operating temperature 5°C to 95°C 5°C to 95°C
Maximum Pressure Tested to 5 Bar Tested to 5 Bar

    Contact Us

    SEA BOX Energy T/A NRG Awareness

    Unit 3010, Euro Business Park,, Little Island, Cork, Ireland, T45 N795

    SEA BOX Energy is a part of SeaBox Group