System schematic showing a system with a gas boiler and a solid fuel stove as the heat sources. The sytem has a domestic hot water (DHW) cylinder, a radiator zone, an underfloor heating zone, and a heat leak radiator and towel rail on the open circuit of the solid fuel stove. The gas boiler, dhw cylinder, underfloor and radiator zones are a part of a seald system, while the solid fuel stove, heat leak radiator and towel rail are a part of an open vented system.
To connect the two different system types an NRG Link is used. The NRG Link ensures that the solid fuel stove has an open system as required for safety reasons, while still being able to transfer its heat to the sealed system.
The NRG Zone 4 manifold ensures that the boiler receives the coldest possible return water so that it is working under optimum conditions and with optimal efficiency. This is especially important for condensing boilers as it greatly increases the likelihood of the boiler operating in condensing mode, which is by far the most efficient. The manifold also ensures that the central heating zones and the DHW cylinder have access to the warmest possible water for their flow. The manifold also provides the system with a full bypass, meaning that the boiler can always maintain its optimal flowrate.
At the same time, it allows any unused heat from the boiler to have a direct bypass back to the Solid Fuel appliance to minimise condensation in the Solid Fuel appliance. This is beneficial since condensation in the solid fuel appliance can lead to corrosion in the appliance.