3
Buffer Tank
A buffer tank is recommended to ensure a trouble free heat pump operation. A suitable buffer tank
can avoid excessive heat pump cycling (switching on and off).
The buffer tank provides a hydraulic separation from the volume flow in the heat pump and
heating circuits. The volume flow in the heat pump circuit remains constant, even if the heating
circuit volume flow is reduced by thermostatic valves.
If the total of the systems water volume is less than 12L/KW then a buffer tank should be added to
reduce the compressor from ON/OFF cycling. This will prolong the compressor life span.
When a buffer tank is installed, the heating system will absorb energy from the buffer tank first.
To save energy consumption ,install the indoor pump P1 that is switched on only when compressor
is on. This is by changing EV01 to “1”.
RT sensor should be taken out of the unit and put into buffer tank’s sensor pocket. The RT sensor
is located at lower submerged sensor pocket of the plate heat exchanger. The RT sensor in the
buffer tank will control the tank temperature by starting and stopping the compressor and pump
together as required.
If RT sensor has not been changed to buffer tank’s sensor pocket when EV01 has been change to
“1”, when the unit reaches its set temperature ,the compressor will stop, pump P1 will also stop
accordingly due to EV01 being set to “1”. When this occurs ,there is no water circulation between
the heat pump and buffer tank. RT will keep its stopped temperature ,not the buffer tank water
temperature. RT then can not switch on compressor and pump P1 even when buffer tank water is
getting cold. Changing the RT sensor into the buffer tank will avoid this problem.
Buffer Tank
