SYX66x Commissioning Guide
V1.10.3 300117
Page 59 of 61
A full range of control features are enabled such as holidays, time extensions, 7 day with 4 periods per day time
controls on both heating and hot water.
Frost protection routines are enabled outside of the heating periods.
SUMMER
The normal hot water controls are operating as in Auto but the heating controls are set to be in frost mode. Full
frost protection of the heating system is in place, safeguarding the building.
Note: If the summer mode is manually selected during a heating time period and pump run-on is enabled, the
boiler(s) will be switched off for the duration of pump run-on with the VT valve opened. When the pump overrun is
finished (15 minute default) the boilers will return to Auto and the Valve will remain closed.
The Pump and VT valve will be exercised daily at Midday for 1 minute to prevent seizure.
CONTINUOUS
The heating is continuously in a Time ON condition providing controlled temperatures to the programmed set
points. The HWS output is continuously ON also. This will also request the boiler(s) to run if the HWS is set to
dependent.
.
FROST
The heating and hot water channels are switched OFF unless a frost condition is detected. Frost protection is
maintained at all times.
SERVICE
The service mode will bring on Boiler No. 1, Boiler No. 2 (if selected), pump and HWS outputs. Service Mode
overrides all temperature control for the duration set. This function will self-cancel and the controller will revert to
the AUTO condition after 30 minutes or the function will be cancelled as soon as the Mode Switch is put into
another position.
ALARM ACKNOWLEGDE AND CLEAR
The first press of any button will wake the Interface and the backlight will illuminate.
Users can Press the Malfunction Messages ! button on the controller facia to view all alarms. This is the Middle
Button on the left side of the LCD Display.
Alarms can be then be acknowledged by pressing the Bottom Left Button on the controller facia.
Cleared Alarms can be cleared from the memory by pressing the ACK bottom left button on the facia and holding
the Alarm Acknowledge button in for more than 5 seconds.
