Section 6
-
Operation of the unit
Page 9
05/20 E&OE
6.1
Unit Operation
Whenever power is applied to the station, the stepper motors are reset to ensure they are in their correct position,
so you are likely to hear a clicking noise from the motors. This is normal. Once the motors are in their correct posi-
tion the unit is ready for its operation.
6.2
Heating
When there is a heating requirement, as programmed in your controller or room thermostat, the station will go into
heating mode. The diverter valve will switch to heating port, the solenoid valve will open, the pump will come on,
and the mixing valve will start to operate and will gradually ramp up the temperature of the heating water to the
set temperature over a period of up to 3 minutes. The unit will continue to provide heating [at set temperature or
‘
district
’
inlet temperature whichever is the lower], until desired room temperature has been achieved or unit
switches into hot water mode, where the solenoid valve will close, and the pump will stop. The unit will restart its
heating cycle every time it switches in to heating mode.
The station will come set as requested if requested at point of order.
Underfloor heating mode, which comes with a cut out Klixon that will stop the heating from working if the
heating flow temperature reaches between 50°C and 55°C. If this occurs, then the heating will have to be
reset on the electronic box before heating mode will operate again [see section 8.0 –
Figure 7].
Radiator heating mode.
6.3 Hot Water
Hot Water has priority [unless remote programmer has been programmed otherwise] and when the hot water flow
detector senses a flow of greater than 2.5l/m then the unit switches into hot water mode. The diverter valve will
switch to hot water port, the solenoid valve will open, the pump will come on, and the mixing valve will start to op-
erate, controlling the
‘
district
’
temperature to the heat exchanger to keep hot water temperature at set tempera-
ture as long as there is sufficient temperature in the district flow.
When the flow rate goes below 2l/m then the unit will switch out of hot water mode. The solenoid valve will close
but the pump will continue for 5 seconds to cool down the heat exchanger to reduce lime scaling.
COLOUR
LIGHT OFF
LIGHT ON
LIGHT FLASHING
ON
Green
Power Off
Power On
N / A
DHW
Yellow
No DHW Demand
In DHW Mode
Preheat Running
CH
Yellow
No CH Demand
In CH Mode
N / A
FAULT
Red
No Fault
Low Temperature
lockout –
re-
quires
reset
Sensor faults –
self
restoring when fault
rectified
6.4 Controller LED display
-
V3 DIRECT
