Connect Heat Pump Combi Model To The Heating System - Worcester GREENSTORE Instruction Manual

Connecting the heat pump to the heating system

Connect heat pump Combi model to the heating system

The built-in control unit controls the heat pump using the outdoor sensor T2 (GT2) and the return sensor T1 (GT1)
according to the outdoor compensated control curve. In the unlikely event the heat pump compressor is unable to meet
the heating requirements, the electric heater starts automatically and together with the heat pump provides the required
temperature. Hot water production is given priority over central heating. Hot water production is controlled by the sensor
T3 (GT3), which is located in the hot water cylinder. When the water in the cylinder reaches the required temperature,
heat is once more supplied to the heating system.
The control unit can also operate a second curve together with a mixing valve. The mixing valve curve must be set lower
than the heat curve for the rest of the heating system. This extra function is used, for example, in a heating system that is a
combination of radiators (higher temperature demand) and underfl oor heating (lower temperature demand).
Connecting the sensors: Return sensor T1 (GT1) and Outdoor sensor T2 (GT2) must always be connected. Sensor T4
(GT4) is only connected if a mixing valve curve is used. The sensor T5 (GT5) is connected when the heat pump is to be
infl uenced by a room sensor. A room sensor is supplied as standard with the heat pump.
An absolute prerequisite for this type of connection is that at least 70% of the nominal fl ow can be maintained throughout
the year. Thermostatic valves must remain fully open in order to ensure this.
* If a bypass and external circulation pump is added, the fl ow over the heating system can be reduced down to 40% of the
nominal fl ow for the heat pump. This means that at least 30% of the thermostatic valves must be fully open. If none of the
above is possible, a 100 litre primary water storage tank should be fi tted.
The length of the bypass should be at least 10 times the inner diameter of the pipe.
Symbols according to ISO/FDIS 14617.
Letter codes according to IEC 61346-2.
This is a principal drawing.
* Mixed heating system
There is a possibility to control a
second heating system with a mixing
valve. This is recommended when a
combination of radiators and a fl oor
heating system is used.
* Expansion vessel
No valve should be fi tted between
the expansion valve and the storage
cylinder.
18
E10 Central heating system
C11: Expansion vessel
G1 (P1): Radiator pump
Q12: Isolating valve
E20 Heating system
E21: Heat pump
E22: Electric water heater
F21: Safety valve
G2 (P2): Heating system pump
Q21: Diverter valve
V21: Filter heating system
E30 Heat transfer fl uid
F31: Safety valve
G3 (P3): Heat transfer fl uid pump
Q32: Isolating valve
Q35: Air vent (manual)
V31: Filter heat transfer fl uid in
E40 Mixed heating system
G4 (P4): Pump for mixed heating system
Q41: Mixing valve
Q42: Isolating valve
E60 Domestic hot water system
V60: Hot water draw-off
W60: Cold water cylinder inlet
C61: Expansion vessel *
F61: Pressure relief valve
F62: Temperature and pressure relief valve
Q62: Isolating valve
Q63: Pressure reducing valve
Q64: Non return valve
Q65: Tundish
T1 Central heating water
T2 Outdoor
T3 Domestic hot water
T4 Mixed heating system
T5 Room
T6 Compressor
T8 Primary fl ow
T9 Primary return
T10 Heat transfer fl uid (coll) in
T11 Heat transfer fl uid (coll) out