SYX66x Commissioning Guide
V1.10.3 300117
Page 11 of 61
3.2 HWS Application Example
Boiler
1
F
R
Boiler
2
C
Valve
C
The HWS Control Circuit is enabled from an IO-1RM relay connected on 30&35 (Pin 8).
This output may also be used to provide a control signal to the HWS Circulation Pump
enable circuit (by others).
The HWS Menu will be “Boiler Linked” for the above scheme.
The Cylinder Thermostat is controlling the valve actuator. The Actuator opens to allow
water through the heating coil. If the Auxiliary input is configured to “HWS Demand”
the Actuator drives open and an auxiliary switch closes the contact to 29&30 (Pin 10).
This requests the boilers to run to the Primary Set point. When the HWS is satisfied
the thermostat opens and this closes the valve. The valve contact then opens and the
boiler set point is relaxed. If there is no heating demand then the boilers will be
switched off. The connection to the controller Pin 10 must be volt free.
If the HWS Demand option is not configured then the boilers will run at the HWS
primary Set point until the HWS Time Period Ends.
F
R
Boiler Flow Sensor located in common flow pipe from boilers.
Return Sensor located in main return pipe to boilers on system side.
HWS Storage
Calorifier
HWS Circ
Note: There is no HWS Temperature Control provided. There is only Boiler demand
control. The HWS Control is by external controls. The HWS Output remains On for the
duration of time schedule or HWS override. The Auxiliary input simply shifts the Boiler
output to the higher of the Heating or HWS Primary Set point. (Subject to Max Boiler
Flow Temp)
Note: HWS Option Relay is required
