System schematic of a open and sealed system with an oil boiler and a solid fuel stove, two central heating zones and a domestic hot water (DHW) cylinder. The boiler and central heating zones are a part of a sealed system while the solid fuel stove is a part of an open system.
To connect the two different system types a NRG Link is used. The NRG Link ensures that the solid fuel stove has an open vented system as required for safety reasons, while still being able to transfer its heat to the sealed system. The DHW cylinder is on the gravity fed circuit of the solid fuel stove and acts as the heat leak of the stove. Since the cylinder has two coils it can also be heated by the sealed system when the solid fuel stove is not burning.
Wiring: This variation of an ‘S’ Plan wiring diagram will prevent the Oil Boiler firing and allow the 2 zones (2 & 3) to receive heat output from the NRG Link when it’s internal pipe thermostat stat calls. The NRG Link pipe thermostat is typically set at 55C and is located on the open Primary return inside the unit.