32
3.2.15.
Installation of the (optional) external probe and sliding temperature operation
The boiler can be connected to an (optional) external temperature probe for sliding temperature operation.
Only original external temperature probes supplied by the manufacturer must be used.
If non-original external temperature probes are used, correct operation of the boiler cannot be guaranteed.
The external temperature probe must be connected by means of a double insulated wire, minimum cross-section 0.35 sq.mm.
The probe must be connected to terminal M8 on the boiler’s printed circuit board (fig. 23).
The temperature probe cables must NOT be routed together with power cables.
The temperature probe must be installed on an outside wall facing north or north-east, in a position protected from atmospheric
agents. Do not install near a window, ventilation openings or sources of heat.
The external temperature probe automatically modifies the CH flow temperature in relation to:
• the outdoor temperature measured
• the thermoregulation curve selected
• the fictitious ambient temperature selected.
The thermoregulation curve is selected via trimmer P6 (fig. 21).
For correct operation, it is important for trimmer P6 to be set to a value of 1-3 (figs. 21 and 22).
The fictitious ambient temperature is set via regulator regulator 4 (fig. 1), which loses its heating temperature control function (see
subsection 1.4.7.) when the probe is installed.
Fig. 22 shows the curves for a fictitious temperature of 20°C.
When this value is increased or decreased via regulator 4, the curves move up or down, respectively.
With a temperature setting of 20°C, for example, if you select the curve corresponding to parameter 1 and the outdoor temperature is
-4°C, the CH flow temperature will be 50°C.
fig. 22
External temperature (°C)
Flo
w t
emper
atur
e (°C
)
Ther
mor
egula
tion
coefficien
t
fig. 21
P6
