Control Unit Rego 800; Automatic Defrosting - Worcester GREENSOURCE User Manual

Control unit

Control unit Rego 800

The control unit makes sure the heat pump gives the best energy savings
and that it runs for many years. The control unit controls and monitors the
heating and hot water supply in your house. The monitoring function is es-
pecially important, it shuts down the heat pump in the event of operational
disturbances so that no critical parts are damaged.
Additional heat gives more output
Additional heating is required when the heat pump is unable to meet the
heating requirements or when it has stopped due to an outdoor temperature
that is too low. The additional heat is provided by an additional electric
heater inside the hot water distribution unit. Note that when the heat pump
is running, the hot water distribution unit only supplies the heat that the
heat pump cannot produce. When the heat pump is once more able to meet
the heating demand, the additional electric heater is automatically switched
off.
Hot water is given priority over heating water
In a house with water based heating a difference is made between heating
water and hot water. The heating water is for radiators and underfl oor coils
and hot water is for showers and taps.
The heating water passes through the hot water cylinder's outer shell and
heats up the hot water heater's inner tank. The control unit makes sure the
heating of hot water is given priority over the heating of the heating water.

Automatic defrosting

Ice may form on the evaporator at outdoor temperatures below +3ºC. When
ice forms to an extent that it obstructs the air fl ow through the evaporator
automatic defrosting starts. Defrosting is controlled by a four-way valve.
The valve reverses the fl ow of the refrigerant in the circuit so that the hot
gas melts the ice on the evaporator fi ns. See Refrigerant fl ow in defrost mode
in the fi gure under the heading How a heat pump works.
There is also a fan defrost function, which means that hot air blows upwards
through the fan to prevent it freezing solid.
Hot water
Heating
water
8