Installations with low-water-content radiators
+ underfloor heating with thermostatic mixing valves
Installation with mixed zones:
• radiators with 2-way zone valves (low flow rate)
• underfloor heating with thermostatic mixing valves
Connection to a boiler that allows a zone control unit to be connected
BOILER: in this case the boiler is configured for connection of a zone control unit. The boiler may heat domestic hot water either instantaneously or via a cylinder, and may have a sealed or an open combustion chamber.
The boiler does not have to be fitted with a By-pass (lmmergas fits this device as standard to the great majority of its boiler models).
ZONES: The system can be divided into a maximum of three zones. One zone can be controlled by the CAR or Super CAR remote control.
The radiator zone fed through a zone valve must always be the first one (No. 1 - that is, the one upstream of the low loss header). In zones with radiant surfaces (e.g. underfloor heating), the zone circulation pumps are installed at the inlet to the zone, with the mixing valve upstream of the pump. The "common" port of the mixing valve is connected upstream of the pump. The underfloor heating safety thermostats must be wired in series to the relevant contacts of the room thermostat.
Installation with mixed zones:
• radiators with 2-way zone valves (low flow rate)
• underfloor heating with thermostatic mixing valves
Connection to a boiler WITHOUT provision for a zone control unit
BOILER: This layout can be used for boilers that are not designed for the electrical connection of a zone control unit.
ZONES: With this arrangement an unlimited number of zones is permitted. None of them can be controlled by the CAR or Super CAR remote controls. The radiator zone fed through a zone valve must always be the first one (No. 1 - that is, the one upstream of the low loss header).
The zone pumps or valves may be powered through the relevant room thermostats even when the boiler is set to summer mode or to DHW priority: this has no adverse effect on the operation of the boiler, but it is nevertheless recommended to switch the zone pumps off during summer mode. In zones with radiant surfaces (e.g. underfloor heating), the zone circulation pumps are installed at the inlet to the zone, with the mixing valve upstream of the pump. The "common" port of the mixing valve is connected to the suction side of the pump. The contact of the underfloor heating safety thermostat must be wired in series to the contact of the relevant room thermostat.