Secon 6 - Operaon of the unit
Page 9
05/20 E&OE
6.1 Unit Operaon
Whenever power is applied to the staon, the stepper motors are reset to ensure they are in their correct posion,
so you are likely to hear a clicking noise from the motors. This is normal. Once the motors are in their correct posi-
on the unit is ready for its operaon.
6.2 Heang
When there is a heang requirement, as programmed in your controller or room thermostat, the staon will go into
heang mode. The diverter valve will switch to heang 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 heang water to the
set temperature over a period of up to 3 minutes. The unit will connue to provide heang [at set temperature or
‘district’ inlet temperature whichever is the lower], unl 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
heang cycle every me it switches in to heang mode.
The staon will come set as requested if requested at point of order.
Underoor heang mode, which comes with a cut out Klixon that will stop the heang from working if the
heang ow temperature reaches between 50°C and 55°C. If this occurs, then the heang will have to be
reset on the electronic box before heang mode will operate again [see secon 8.0 – Figure 7].
Radiator heang mode.
6.3 Hot Water
Hot Water has priority [unless remote programmer has been programmed otherwise] and when the hot water ow
detector senses a ow 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 sucient temperature in the district ow.
When the ow rate goes below 2l/m then the unit will switch out of hot water mode. The solenoid valve will close
but the pump will connue for 5 seconds to cool down the heat exchanger to reduce lime scaling.
COLOUR LIGHT OFF LIGHT ON LIGHT FLASHING
ON Green Power O 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
reced
6.4 Controller LED display
-V3 DIRECT
