OPTIONAL CONTROLS
TR05A153.B1107
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7.2 Weather compensating controls
An Outside Sensor is available for use with this appliance and is strongly recommended in order to maximise
appliance efficiency and user comfort.
The sensor is easy to wire, connecting directly to the
Se
terminals of the mains supply terminal board.
The control system carefully modulates the central heating flow temperature in accordance with the outside
temperature as measured by the sensor.
7.2.1 Fitting the outside sensor
To fit the outside sensor:
•
Isolate the electricity, water and gas supplies to the appliance;
•
Remove the front casing panel of the boiler (refer to 6.3 for guidance);
•
Remove terminal block cover
A
of the control panel (see Figure 59);
•
Connect the two wires of the sensor to the connections marked
Se
on terminal block
B
(see Figure 59);
•
Replace terminal block cover
A
.
External Controls:
- Room thermostat
- Programmer
A
- S-Plan system
S
e
S
e
T
a
N
L
B
T
a
Outside
temperature
sensor
2
M1 1
Figure 59: Outdoor Sensor connection
7.2.2 Controlling the appliance
With the sensor fitted, the
CH Control
knob no longer sets the CH flow temperature. This is now governed by the
control system. Instead, the
CH Control
knob is used to set the response of the control system to the outside
temperature.
When the
CH Control
knob is turned, numbers between 0 and 9 are temporarily displayed on the control panel
display. The numbers correspond to the control profiles depicted in Figure 60, relating the CH flow temperature,
Tm
, to the outside temperature,
Te
. The appliance will control the CH flow temperature between the minimum and
maximum temperatures as set by Control Parameter 3 (see Section 5.6).
