AERMEC WMT21 Manuel D'installation page 51

APPENDIX
HEATING/COOLING SELECTION
Heating or cooling modes are selected by keeping the  "menu" button
depressed for some seconds, until the display shows one of the following
texts which indicates the current mode:
HEA
: Heating mode
COO
: Cooling mode
Then, by pressing the "" or "" or " ", the user can change the desired
mode, cycling between heating and cooling. Depressing any of the other
buttons results in saving the choice and quitting the menu.
When the thermostat is configured for automatic or centralised heating/
cooling selection, the selection cannot be manually changed and if tried,
the display shows the flashing " " icon.
SUPPLY PIPE SENSOR
This controller features an input for the delivery water temperature sensor:
when this sensor is installed the controller can automatically understand
whether it should be working in "cooling" mode or in "heating" mode: this
function is called "water temperature changeover".
The water temperature is also used to perform the "cut-off thermostat"
function.
Alternatively a bimetallic thermostat can be wired to the input to get the
"cut-off" function.
EXTERNAL INPUTS - TERMINALS 3, 4 AND 16
The thermostat has three external inputs that can be associated to
different functions throug parameters C17, C18 and C19.
Signals to terminals 3 and 4 can be connected to terminals 3 and 4 of other
thermostats in the same building for centralised functions.
The signal on terminal 16 cannot be connected to other thermostats.
Functions that can be associated to the inputs are:
"Centralised Heating/Cooling" function:
When installations have multiple thermostats in a single building, the
centralised inputs of each thermostat can be connected together and
controlled by the central heating room.
This way the central heating room determines whether the thermostats
must operate in the heating or cooling mode.
"Economy" function:
The input activates/deactivates the economy mode (see the "Economy
function" paragraph). This function can be associated with the following
icon: " " . The thermostat is sensitive to the input status changes
and not to the level, so it is always possible to change the economy status
with the " " button (if enabled).
"Regulation stop" function
The input can suspend or reactivate room temperature regulation. When
temperature regulation is suspended the fan is stopped, the valves remain
closed and the relevant symbols on the display will flash. This function
can be associated with one of these icons: "
an input is configured for the "regulation stop" function and the "
icon, the "window contact" function is performed. Connecting a window
contact to the input, when the window is open the "
on the display and the temperature regulation will be suspended.
Note: there are limitations for window contact use. Carefully read the
paragraph "ATTENTION".
"Thermostat ON / OFF" function
The input turns the thermostat on or off, like pressing the " " button.
Since the thermostat is sensitive to input status changes and not to the
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" or " " o " " . When
"
" icon will appear