1-37
INSTALLATION
SFC COMBI BOILERS SFC-99, SFC-125
Figure 38: Terminal strip for connection of the DHW Aquastat (optional), thermostat or end switch(es) (mandatory), outdoor sensor
(optional)
1.9.4 Thermostat / Sensor Wiring
A thermostat from a single zone heating system can be connected directly to the
controller’s X13 terminals 1 and 2. Do not apply power to the X13 terminal strip.
An outdoor sensor is not required for the unit to operate. If an outdoor sensor is
not connected, the unit will operate as a set point unit and operate at its design
supply temperature.
If outdoor reset functionality and the summer shut-down feature are desired
connect the supplied Outdoor sensor to X13 terminals 3 and 4. The outdoor
sensor is a 12KΩ thermistor type sensor.
The sensor should be installed:
•
On the exterior of the building on the north side.
•
So that it is not effected by any heat sources from the building such as a dryer
or exhaust fan outlet, relief air or combustion air grill above a window or door,
or mounted directly under a deck or soffit overhang.
DHW Aquastat or 10KΩ sensor can be connected to the controller’s X13
terminals 4 and 5. Do not apply power to the X13 terminal strip.
