INSTALLATION
22
LOGIC HIU
-
Installation & Servicing / Users
39 THE USER INTERFACE
The user interface built into the controls consists of:-
1
Commissioning set up potentiometers (found at the top
right hand side of the control unit under a rubber cover
2
Customer unit rest button and a 4 LED light display.
a
Green light (On) (Left hand side)
= Power On 230 V (ac)
b
Yellow light (DHW)
= DHW domestic hot water in operation.
c
Yellow Light (CH)
= CH central heating in operation.
d
Red Light (Fault)
=Fault
detected
Reset Key
This allows normal function to be restored after the safety
thermostat has been triggered and during the activation and
deactivation of the under floor heating function.
40 TEMPERATURE SETTINGS (MT & HT)
These are used to set the required specified output
temperatures for the (CH) central heating and the (DHW)
domestic hot water outputs.
To access the two temperature adjustment potentiometers
remove the black rubber insert cover (top right hand of control
box). Using a fine bladed screw driver to adjust as required
P2
Heating temperature adjustment potentiometer.
P1
Domestic hot water temperature adjustment
potentiometer.
41 DISPLAY (MT ONLY)
Actual Central heating (CH) Set Point
Temperature Value display permanently
when in use or been set.
Radiator Symbol On when setting and
displaying
Flashes On / Off when in operation
Actual Domestic Hot Water (DHW)
Set Point Temperature Value display
permanently when in use or been set.
Radiator Symbol On when setting and
displaying
Flashes On / Off when in operation.
NOTE when in standby the display will alternate every 5
second displaying the CH and the DHW temperatures.
42 DOMESTIC WATER GENERATION:
DHW PREHEATING FUNCTION (MT & HT)
The domestic water preheating function is signaled by the
flashing yellow DHW LED. The function is enabled by setting
dip switch 5 to the ON position.
During periods when the domestic water cycle is not used,
if the DHW probe detects a temperature 10°C below the
SET value, the controller partially opens the domestic water
modulating valve for the time required (max. 5 mins) to bring
the temperature detected up to a value 5°C below the set
point value.
The domestic water preheating function is signalled by the
flashing yellow DHW LED. This function is less of a priority
than any domestic water or heating cycles.
DIRECT
OPERATION
RESET
5
ON
43 HEATING CYCLE: ON/OFF
REGULATION (HT ONLY)
When the room thermostat requests the start of a heating
cycle, the valve is opened completely, allowing water to
circulate at the temperature supplied by the central heating
system (ON-OFF regulation).
The valve is closed on completion of the heating cycle. The
active heating cycle is signaled by the yellow CH LED which
comes on. No value is shown on the display.