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15-1. Description of the electrical connections to the boiler
Turn the control box downward to access terminal boards M1 and M2 used for the electrical connec-
tions by removing the two protective covers (see figure 11).
Terminals 1-2
: connection of SIEMENS model QAA73 temperature regulator supplied as accessory.
Connection polarity is irrelevant.
The jumper fitted across the “TA” terminals 3-4 must be removed.
Read the instructions supplied with this accessory for correct installation and programming proce-
dures.
Terminals 3-4
: “TA”, room temperature thermostat connection. Thermostats with integral accele-
rator resistor must not be used. Check that there is no voltage across the ends of the two thermostat
connection wires.
Terminals 5-6
: “TP” floor temperature thermostat connection (commercially available device). Check
that there is no voltage across the ends of the two thermostat connection wires.
Terminals 7-8
: connection of SIEMENS model QAC34 outdoor temperature probe supplied as
accessory..
Read the instructions supplied with this accessory for correct installation procedures.
Terminals 9-10
: connection of domestic hot water precedence temperature sensor supplied as acces-
sory for connecting heating-only boilers to an external water heater.
Terminals a-b (230V)
: electricity supply for a zone valve / pump
See instructions in the “connecting a zone system” section.
15-2. Connecting the QAA73 temperature regulator.
The SIEMENS model QAA73 temperature regulator (optional accessory) must be connected to
terminals 1-2 of terminal board M2 in figure 11.
The jumper across terminals 3-4, provided for connection of a room temperature thermostat, must
be removed.
The settings of the domestic hot water temperature and domestic hot water production schedule must
be made using this device.
The timed program of the central heating circuit must be set on the QAA73 if there is a single zone,
or in relation to the zone controlled by the QAA73 device.
The timed program for the central heating circuit of the other zones can be set directly on the boiler
control panel.
See the instructions provided with the QAA73 temperature regulator for the user parameter pro-
gramming procedure.
IMPORTANT
: For systems divided into zones, parameter 80 “HC2 gradient”, which can be set on
the QAA73 temperature regulator, must be set as _ _ . _ “
not active
”.
QAA73: parameters the installer can set (service)
By pressing the two PROG buttons together for at least three seconds it is possible to access the list
of parameters that the installer can display and/or set.
Press either of these buttons to change the parameter to display or change.
Press the [+] or [-] key to change the value displayed.
Press either of the PROG buttons again to save the change.
Press the information button (i) to quit programming.
Here follows a list of the most commonly used parameters:
