Type Plate; Appliance Type Overview And Accessories; Product Dimensions And Minimum Clearances - Worcester Greenstar HIU Installation And Maintenance Instructions Manual

System separation
• The two heat exchangers for DHW and heating hydraulically
disconnect the primary heating circuit from the heating circuit.
DHW mode
• Opening the water tap activates the flow turbine [31]. The minimum
volumetric flow rate is 2 l/min.
• The DHW control valve [1] modulates the heating water on the
primary side to achieve the preset DHW temperature.
• The control valve for the heating remains closed [3] (DHW priority
function).
• Primary side heating water flows through the plate heat exchanger
[32] and heats the potable water instantaneously.
• If there is a risk of scalding, the thermal overload protection [25]
interrupts the flow. The valve opens automatically following a cool
down time.
Heating mode
• The control valve for the DHW [1] remains closed until DHW is
requested (DHW priority function).
• The heating control valve [3] modulates according to the required
heating capacity. The flow temperature remains the same and
corresponds to the flow temperature of the primary circuit.
Summer bypass function
• This function bypasses the longer heating-up period of the pipework
in the primary circuit which occurs when the heat interface unit has
been inactive for a longer period. This reduces the DHW heating
waiting times. The heat exchanger is not kept warm continuously. The
summer bypass function can be activated in two ways.
• Variant 1 (standard) - electronic keep hot without thermal bypass,
using the default electronic bypass. The DHW control valve [1] is
used to allow water to run through HIU. The trigger temperature for
this function is fixed at 41°C and can only be changed by a Sense II
room controller (accessory). With this version, the quantity of heat is
recorded by the heat meter (option) [10].
• Variant 2 (accessory) - using the thermal bypass option [12]: the
heating water in the primary circuit flows through the bypass valve.
This ensures that the temperature of the hot water at the heat
interface unit is 30-70 °C. In this case the quantity of heat is not
recorded by the heat meter (accessory) [12]!
If the bypass valve is installed, the electronic bypass function must not
be selected in the room controller and the jumper must be removed
(Fig. 53, page 29 [19]).
The BESA requirements are only achieved with the electronic bypass -
not with the thermal bypass (accessory).
Frost protection
• System frost protection: as soon as the temperature sensor [10]
sends a frost protection signal, the heating pump is activated.
• Device frost protection: as soon as the temperature at the flow
temperature sensor [24] for the heating is below 5 °C, the control
valve opens the heating.
Limiting the return temperature in the heating circuit
• If the system is designed correctly, it is not necessary to limit the
return temperature [8].
• The return temperature limit is set to 50 °C at the factory.
• This temperature can only be changed with the room controller Sense
II.
• When the room controller is removed, the set value is saved.
Greenstar – 6721852556 (2022/11)
2.3

Type Plate

The data plate includes the performance information, approval data and
serial number of the product [2]. There is an additional data plate behind
the control unit [1].
Fig. 4 Type plate and data plate
2.4

Appliance type overview and accessories

Example appliance: HIU KE
• HIU = heat interface unit
• E = differential pressure control valve (DPCV)
• K = higher DHW output
Typ Typ-Nr.
HIU 7735600658
1)
HIU 7735600726
HIU E 7735600659
1)
HIU E 7735600724
HIU KE 7735600661
1)
HIU KE 7735600725
1) with heat meter wired Mbus (standard)
Table 2 Appliance type overview
Refer to the Technical product brochure for a complete overview of all
available accessories. Information on assembly is enclosed with the
accessories.
Flushing valve
Vertical connector pipes (set)
Heat meter adapter kit
Thermal overload protection
Sense II (room controller)
Security fixings
Keyless filling loop
Summer bypass valve
Mounting plate
Table 3 Accessory part
2.5

Product dimensions and minimum clearances

The protection class of the station is IPX4D.
Product Information
2
0086
0010025537-01
Accessory NOT possible
Heat meter wired Mbus
Heat meter adapter kit
Heat meter wired Mbus
Heat meter adapter kit
Heat meter wired Mbus
Heat meter adapter kit
1
5