Westen novadens Series Guide

wall-mounted condensing boiler
instructions manual for users and fitters
Hастенные газовые конденcaтные котлы
Руководство по эксплуатации и монтажу
Kondenzációs fali gázkazánok
Felhasználói és szerelői kézikönyv
Centrale murale cu gaz, cu condensare
manual de instrucţiuni destinat utilizatorului şi instalatorului
GB
HU
RO
RU
ΕΠΙΤΟΙΧΙΟΙ ΛΕΒΗΤΕΣ ΣΥΜΠΥΚΝΩΣΗΣ
ΕΓΧΕΙΡΙΔΙΟ ΧΡΗΣΗΣ ΓΙΑ ΤΟ ΧΡΗΣΤΗ ΚΑΙ ΤΟΝ ΕΓΚΑΤΑΣΤΑΤΗ
GR

2925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE USER
Dear Customer,
We are sure your new boiler will comply with all your requirements.
Purchasing one of our products satises your expectations: good functioning, simplicity and ease of use.
Do not dispose of this booklet without reading it: you can nd here some very useful information, which will
help you to run your boiler correctly and efciently.
Do not leave any parts of the packaging (plastic bags, polystyrene, etc.) within children’s reach as they are a
potential source of danger.
Our boilers bear the CE mark in compliance with the basic requirements as laid
down
in the following Directives:
-Gas Directive 90/396/EEC
- Performance Directive 92/42/EEC
- Electromagnetic Compatibility Directive 2004/108/EEC
- Low Voltage Directive 2006/95/EC
1. Instructions prior to installation 3
2. Instructions prior to commissioning 3
3. Commissioning of the boiler 3
4. Filling the boiler 6
5. Switching the boiler off 6
6. Prolonged standstill of the system. Frost protection 6
7. Gas change 6
8. Servicing instructions 6
9. General information 7
10. Instructions prior to installation 7
11. Boiler installation 8
12. Boiler size 8
13. Fittings present in the packaging 9
14. Installation of ue and air ducts 9
15. Connecting the mains supply 13
16. Changing gas type 19
17. Displaying electronic control card parameters on the boiler display (“INFO” mode) 22
18. Control and operation devices 23
19. Positioning of the ignition and ame sensing electrode 24
20. Check of combustion parameters 24
21. Activating the ue-sweeper function 25
22. Output / pump head performances 25
23. How to disassemble the DHW heat exchanger 26
24. Cleaning the cold water lter 26
25. Annual mainenance 27
26. Using the Siemens QAA73 temperature regulator to program boiler parameters 27
27. Boiler schematic 29
28. Illustrated wiring diagram 30
29. Technical data 32
CONTENTS
ISTRUCTIONS PERTAINING TO THE USER
ISTRUCTIONS PERTAINING TO THE INSTALLER

3925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE USER
This boiler is designed to heat water at a lower than boiling temperature at atmospheric pressure. The boiler must be
connected to a central heating system and to a domestic hot water supply system in compliance with its performances
and output power.
Have the boiler installed by a Qualied Service Engineer and ensure the following operations are accomplished:
a) accurate purging of the whole pipework in order to remove any deposits.
b) careful checking that the boiler is t for operation with the type of gas available. For more details see the notice on the
packaging and the label on the appliance itself.
c) careful checking that the ue terminal draft is appropriate; that the terminal is not obstructed and that no other appliance
exhaust gases are expelled through the same ue duct, unless the ue is especially designed to collect the exhaust gas
coming from more than one appliance, in conformity with the laws and regulations in force.
d) careful checking that, in case the ue has been connected to pre-existing ue ducts, thorough cleaning has been carried
out in that residual combustion products may come off during operation of the boiler and obstruct the ue duct.
1. INSTRUCTIONS PRIOR TO INSTALLATION
Initial lighting of the boiler must be carried out by a licensed technician. Ensure the following operations are carried out:
a) compliance of boiler parameters with (electricity, water, gas) supply systems settings.
b) compliance of installation with the laws and regulations in force.
c) appropriate connection to the power supply and grounding of the appliance.
The names of authorized Service Centres are listed on the accompanying sheet.
Failure to observe the above will render the guarantee null and void.
Prior to commissioning remove the protective plastic coating from the unit. Do not use any tools or abrasive detergents
as you may spoil the painted surfaces.
2. INSTRUCTIONS PRIOR TO COMMISSIONING
3. COMMISSIONING OF THE BOILER
To correctly light the burner proceed as follows:
1) provide power supply to the boiler;
2) open the gas cock;
3) follow the directions given below regarding the adjustments to be made at the boiler control panel.

4925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE USER
0806_0101 / CG_1816
The central heating system is disabled when the selector (1) is turned to Summer position ( ). All boiler safety systems
(the anti-freeze system and the pump and three way valve anti-blockage systems) and the domestic hot water system
remain active.
IMPORTANT: When you rst switch the boiler on, the burner may fail to light and the boiler may block until all the air
is expelled from the gas supply pipe.
If this happens, simply turn the selector (1) to ( ) for at least 1 second, then repeat the burner lighting process until pure
gas reaches the burner and it lights.
Legend:
1 Summer-Winter-Reset selector
2 Central heating function indicator
3 Domestic hot water (DHW) function indicator
4 Flame indicator
5 Display
6 Central heating temperature control knob
7 Domestic hot water temperature control knob
8 Pressure gauge
Figure 1
3.2 ADJUSTING DOMESTIC HOT WATER TEMPERATURE
3.1 ADJUSTING ROOM TEMPERATURE
The boiler electronically modulates the burner ame according to
the setting of the hot water temperature control knob (7) and the
water ow.
The system therefore guarantees that water temperature from the
boiler remains constant even when only a small ow is being drawn
off.
To save energy, keep the domestic hot water temperature control
knob turned to “--comfort--” (gure 2).
In the winter it will probably be necessary to increase the temperature
of the hot water to suit conditions.
The central heating system must be equipped with a thermostat to control room temperature.
If no room temperature thermostat is installed when the boiler is rst started up, room temperature can be controlled using
the control knob (6) instead.
Simply turn the control knob clockwise to increase room temperature or anti-clockwise to decrease it. The electronic ame
modulation system adapts the gas ow to the burner to suit varying heat exchange requirements as the boiler achieves
the set temperature.
Figure 2
0301_1002

5925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE USER
3.3 ERROR MESSAGES AND RESETTING THE BOILER
If a fault occurs, the display reads out an error message identifying it.
NOTE: If the error message contains more than 2 digits (e.g. E133), the display reads out the rst two digits “E1”
followed, by the last two digits “33”, as shown in gure 3.
Figure 3
0402_2504
3.3.1 Table of faults and error messages
Corrective action
Call an authorised service centre.
Call an authorised service centre.
Call an authorised service centre.
Call an authorised service centre.
Turn selector (1) (gure 1) to “R” for at least 1 second. If this fault persists, call an
authorised service centre.
Check that the pressure in the system is as specied. See the section on lling the
system. If this fault persists, call an authorised service centre.
Turn selector (1-gure 1) to “R” for at least 1 second. If this fault persists, call an au-
thorised service centre.
Turn selector (1) (gure 1) to “R” for at least 1 second. If this fault persists, call an
authorised service centre.
Turn selector (1) (gure 1) to “R” for at least 1 second. If this fault persists, call an
authorised service centre.
Call an authorised service centre.Check the position of the ignition electrodes
(section 18).
Wait until the power supply voltage returns to the normal value (230V).
The reset to normal operation is automatic.
Call an authorised service centre.
The displayed anomaly is temporary. The reset is automatic
Description of fault
Outdoor temperature sensor fault
Central heating NTC sensor fault
Flue NTC sensor fault
Domestic hot water NTC sensor fault
Safety thermostat or fume
sensor tripped
No signal from water pressure switch
Safety operation due to ow water fault
or air inside circuit
NTC ue sensor has cut out for ove-
rheat
Gas supply fault
Boiler control card fault
Power supply voltage too low
Fan has not reached threshold speed
Air inside circuit
Error
code
E10
E20
E28
E50
E110
E119
E125
E130
E133
E151
E156
E160
E193
All the faults are displayed in order of importance; if several faults occur simultaneously, the rst to be displayed is the one
with highest priority. After the cause of the rst fault has been removed, the second one will be displayed, and so on.
If any given fault occurs frequently, contact the authorised Service Centre.

6925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE USER
4. FILLING THE SYSTEM
5. SWITCHING THE BOILER OFF
7. GAS CHANGE
These boilers produced for natural gas can be converted to work with LPG.
Any gas change must be effected by a Qualied Service Engineer.
We recommend you avoid draining the whole system as water replacements engender purposeless and harmful limestone
deposits inside the boiler and on the heating elements. In case the boiler is not operated during wintertime and is therefore
exposed to danger of frost we suggest you add some specic-purpose anti-freeze to the water contained in the system
(e.g.: propylene glycole coupled with corrosion and scaling inhibitors).
The electronic management of boilers includes a “frost protection” function in the central heating system which operates
the burner to reach a heating ow temperature of 30° C when the system heating ow temperature drops below 5°C.
The frost protection function is enabled if:
* electrical supply to the boiler is on;
* the gas service cock is open;
* the system pressure is as required;
* the boiler is not blocked.
6. PROLONGED STANDSTILL OF THE SYSTEM. FROST PROTECTION
The boiler is equipped with a water pressure switch that prevents the boiler from starting up if there is no water in the
system.
Boiler filling cock Boiler drain cock
Figure 4a
0402_2505
IMPORTANT: Regularly check that the pressure gauge (8 - gure 1) reads out a pressure of 1 - 1.5 bar when the central
heating system is cold. Open the boiler drain cock to reduce pressure if it is too high. Open the boiler lling cock (gure 4)
to increase pressure if it too low. Always open the lling cock very slowly to allow any air to bleed off.
If the pressure in the system drops frequently, contact an authorised service centre to have the system checked.
To switch the boiler off, simply turn the selector “1” to the “0” position. This switches off the electricity supply to the
appliance.
8. SERVICING INSTRUCTIONS
To maintain efcient and safe operation of your boiler have it checked by a Qualied Service Engineer at the end of every
operating period. Careful servicing will ensure economical operation of the system. Do not clean the outer casing of the
appliance with abrasive, aggressive and/or easily ammable cleaners (i.e.: gasoline, alcohol, and so on). Always isolate
the electrical supply to the appliance before cleaning it (see section 5 Turning off the boiler).
NOVADENS 240 - 280 NOVADENS 1.240
0803_0304 / CG_2042
Boiler filling cock
Figure 4b

7925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE INSTALLER
The following remarks and instructions are addressed to Service Engineers to help them carry out a faultless installation. In-
structions regarding lighting and operation of the boiler are contained in the ‘Instructions pertaining to the user’ section.
Note that installation, maintenance and operation of the domestic gas appliances must be performed exclusively by qua-
lied personnel in compliance with current standards.
Please note the following:
* This boiler can be connected to any type of double- or single feeding pipe convector plates, radiators, thermoconvectors.
Design the system sections as usual though taking into account the available output / pump head performances, as
shown in chapter 22.
* Do not leave any packaging components (plastic bags, polystyrene, etc.) within children’s reach as they are a potential
source of danger.
* Initial lighting of the boiler must be effected by a Qualied Service Engineer.
Failure to observe the above will render the guarantee null and void.
9. GENERAL INFORMATION
10. INSTRUCTIONS PRIOR TO INSTALLATION
This boiler is designed to heat water at a lower than boiling temperature at atmospheric pressure. The boiler must be con-
nected to a central heating system and, on models withis option, to a domestic hot water supply system in compliance with
its performances and output power.
Before connecting the boiler have the following operations effected:
a) accurate purging of the whole pipework in order to remove any pipe-threading, soldering or solvent deposits which may be
contained in the different sections of the central heating system.
b) careful checking that the boiler is t for operation with the type of gas available. For more details see the notice on the
packaging and the label on the appliance itself.
c) careful checking that the ue terminal draft is appropriate; that the terminal is not obstructed and that no other appliance
exhaust gases are expelled through the same ue duct, unless the ue is especially designed to collect the exhaust gase
coming from more than one appliance, in conformity with the laws and regulations in force.
d) careful checking that, in case the ue has been connected to pre-existing ue ducts, thorough cleaning has been carried
out in that residual combustion products may come off during operation of the boiler and obstruct the ue duct.
To ensure correct operation of the appliance and avoid invalidating the guarantee, observe the following precautions
1. Hot water circuit:
if the water hardness is greater than 20 °F (1 °F = 10 mg calcium carbonate per litre of water) install a polyphosphate or com-
parable treatment system responding to current regulations.
2. Heating circuit
2.1. new system
Before proceeding with installation of the boiler, the system must be cleaned and ushed out thoroughly to eliminate
residual thread-cutting swarf, solder and solvents if any, using suitable proprietary products.
2.2. existing system:
Before proceeding with installation of the boiler, the system must be cleaned and ushed out to remove sludge and
contaminants, using suitable proprietary products.
To avoid damaging metal, plastic and rubber parts, use only neutral cleaners, i.e. non-acid and non-alkaline (e.g. SENTINEL
X400 and X100), proceeding strictly in accordance with the maker’s directions.
Remember that the presence of foreign matter in the heating system can adversely affect the operation of the boiler (e.g. ove-
rheating and noisy operation of the heat exchanger)
IMPORTANT: when connecting an instantaneous boiler (mixed) to a system with solar panels, the maximum tem-
perature of the DHW at the boiler inlet must not be greater than:
• 60°C with a ow limiting device
• 80°C without a ow limiting device

8925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE INSTALLER
11. BOILER INSTALLATION
12. BOILER SIZE
Decide upon the boiler location, then tape the template on the wall.
Connect the pipework to the gas and water inlets prearranged on the template lower bar.
If you are either installing the boiler on a pre-existent system or substituting it, we suggest you also t settling tanks on
the system return pipework and under the boiler to collect the deposits and scaling which may remain and be circulated
in the system after the purge.
When the boiler is xed on the template connect the ue and air ducts (ttings supplied by the manufacturer) according
to the instructions given in the following sections.
Connect the condensate outlet to the siphon supplied with the boiler. Connect the siphon to a drain, making sure there is
a continuous slope. Horizontal sections must be avoided.
0505_2001
Figure 5
MR: G3/4 heating ow
US: G1/2 domestic hot water outlet
GAS: G3/4 gas inlet to the boiler
ES: G1/2 cold water inlet
RR: G3/4 heating return
SC: condensate drain
9912220300
BOILER WIDTH 450
BOILER CONNECTION POINTS
BOILER HEIGHT 780
Figure 6
0806_0102 / CG_1817
0806_0801 / CG_1399
novadens 1.240 novadens 240 - 280
MR: G3/4 heating ow
US: G3/4 domestic hot water boiler delivery
GAS: G3/4 gas inlet to the boiler
ES: G1/2 cold water inlet
RR: G3/4 heating return
SC: condensate drain

9925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE INSTALLER
14. INSTALLATION OF FLUE AND AIR DUCTS
13. FITTINGS PRESENT IN THE PACKAGING
• template
• gas cock (1)
• inlet water tap with lter (2)
• seals
• telescopic joints
• 8 mm wall plugs and hooks
010828_0200
C33 C33
C13 C13
C43 C53 C83
Figure 8
We guarantee ease and exibility of installation for a gas-red forced draft boiler
thanks to the ttings and xtures supplied (described below).
The boiler is especially designed for connection to an exhaust ue / air ducting, with
either coaxial, vertical or horizontal terminal. By means of a splitting kit a two-pipe
system may also be installed.
In case exhaust and intake flues not supplied by WESTEN have been
installed, these must be certified for the type of use and must have a
maximum pressure drop of 100 Pa.
Warnings for the following types of installation:
C13, C33 The terminals for the split ue must be provided for within a square with 50
cm sides. Detailed instructions are given together with each accessory.
C53 The terminals for combustion air intake and for the expulsion of combustion
products must not be provided for on opposite walls of the building.
C63 The maximum pressure drop of the ducts must not exceed 100 Pa. The
ducts must be certied for the specic use and for a temperature of over
100°C. The chimney ue must be certied in accordance with the prEN
1856-1 Regulation.
C43, C83 The chimney or ue used must be suitable for the use.
Figure 7a
0806_0106 / CG_2041
21 Figure 7b
0806_0107 / CG_2042
21
NOVADENS 240 - 280 NOVADENS 1.240
WARNING
To guarantee more operating insurance it is necessary to assure the flue pipes to the wall using the apposite
clamps.

10 925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE INSTALLER
14.1 HORIZONTAL FLUE TERMINAL Ø 60/100 MM INSTALLATION OPTIONS
14.2 LAS FLUE DUCT Ø 60/100 MM INSTALLATION OPTIONS
… coaxial flue - air duct (concentric)
990519_0400
Concentric outlet
Figure 9
This type of duct allows to disengage exhaust gases and to draw combu-
stion air both outside the building and in case a LAS ue is tted.
The 90° coaxial bend allows to connect the boiler to a ue-air duct in any
direction as it can rotate by 360°. It can moreover be used as a supple-
mentary bend and be coupled with a coaxial duct or a 45° bend.
If the ue outlet is placed outside, the ue-air ducting must protrude at
least 18mm out of the wall to allow alluminium weathering tile to be tted
and sealed to avoid water leakages.
Ensure a minimum downward slope of 1 cm towards the boiler per each
metre of duct length.
A 90° bend reduces the total duct length by 1 metre.
A 45° bend reduces the total duct length by 0.5 metre.
9912220900
L max = 10 m Ø 60/100
L max = 25 m Ø 80/125
0002230400
L max = 10 m Ø 60/100
L max = 25 m Ø 80/125
L max = 9 m Ø 60/100
L max = 24 m Ø 80/125
Flue
terminal
diameter
100 mm
133 mm
133 mm
-
Each 45° bend
reduces the duct
max. length by
0,5 m
0,5 m
0,25 m
0,25 m
Each 90° bend
reduces the duct
max. length by
1 m
1 m
0,5 m
0,5 m
Max. length
of flue duct
10 m
25 m
15 m
80 m
Flue duct terminal
Coaxial Ø 60/100 mm
Coaxial Ø 80/125 mm
Vertical two-pipe
Horizontal two-pipe
Outer
terminal
diameter
100 mm
125 mm
80 mm
80 mm

11 925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE INSTALLER
14.3 VERTICAL FLUE TERMINAL Ø 60/100 MM INSTALLATION OPTIONS
This type of installation can be carried out both on a at or pitched roof by tting a terminal, an appropriate weathering
tile and sleeve, (supplementary ttings supplied on demand).
9912221000
… separated flue-air ducting
This type of ducting allows to disengage exhaust ue gases both outside the building and into single ue ducts.
Comburant air may be drawn in at a different site from where the ue terminal is located.
The splitting kit consists of a ue duct adaptor (100/80) and of an air duct adaptor.
For the air duct adaptor t the screws and seals previously removed from the cap.
011015_0100
flue duct adaptor
Intake air duct adaptor
The 90° bend allows to connect the boiler to ue-air ducting regardless of direction as it can be rotated by 360°. It can
moreover be used as a supplementary bend to be coupled with the duct or with a 45° bend.
Figure 10
L max = 10 m Ø 60/100
L max = 25 m Ø 80/125
L max = 8 m Ø 60/100
L max = 23 m Ø 80/125
L max = 9 m Ø 60/100
L max = 24 m Ø 80/125

12 925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE INSTALLER
14.4 SEPARATED HORIZONTAL FLUE TERMINALS INSTALLATION OPTIONS
0806_0103 / CG_1818
Figure 11
A 90° bend reduces the total duct length by 0.5 metre.
A 45° bend reduces the total duct length by 0.25 metre.
IMPORTANT: Ensure a minimum downward slope of 1 cm toward the boiler per each metre of duct length.
Make sure that the exhaust and intake ducts are securely xed to the walls.
(L1 + L2) max = 80 m
L max = 15 m
0207_0907
010828_06≤00
The maximum length of the suction duct
must be 15 metres.

13 925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE INSTALLER
15. CONNECTING THE MAINS SUPPLY
14.5 SEPARATED VERTICAL FLUE TERMINALS INSTALLATION OPTIONS
IMPORTANT: if tting a single exhaust ue duct, ensure it is adequately insulated (e.g.: with glass wool) wherever
the duct passes through building walls.
For detailed instructions concerning the installation of ttings refer to the technical data accompanying the ttings.
L max = 14 m
L max = 15 m
010828_0700
Electrical safety of the appliance is only guaranteed by correct grounding, in compliance with the applicable laws and
regulations.
Connect the boiler to a 230V monophase + ground power supply by means of the three-pin cable supplied with it and
make sure you connect polarities correctly.
Use a double-pole switch with a contact separation of at least 3mm in both poles.
In case you replace the power supply cable t a HAR H05 VV-F’ 3x0.75mm2cable with an 8mm diameter max.
The fuse, a fast-acting type rated 2A, are incorporated into the power supply terminals (remove the black fuse holder to
enable inspection and/or replacement).
Figure 12 0409_0207
Terminals M1
Terminals M2
Cover
Cover
0409_0201
2
1
N
L

14 925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE INSTALLER
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 connections by removing the
two protective covers (see gure 12).
Terminals 1-2, terminal board M1: room temperature thermostat “TA”.
Terminals 4-5, terminal board M2: connections for the optional SIEMENS QAA73 temperature regulator. These connec-
tions do not have any specic polarity.
Remove the bridge between terminals 1-2 “TA” on terminal board M1.
Read the instructions provided with the temperature regulator to ensure correct installation and programming.
Terminals 7-8: connections for the optional SIEMENS QAC34 outdoor temperature sensor. Read the instructions provided
with the outdoor temperature sensor to ensure correct installation.
Terminals 9-10: connections for the optional domestic hot water priority sensor, for connecting single system boilers to
external DHW boilers.
WARNING
If the heating is directly connected to a floor heating system, a safety overheating thermostat should be provided
by the installer.
An optional interface card is required to connect the QAA73 temperature regulator to boiler’s own electronic control card.
Connect the interface card to connector X 300 on the boiler’s electronic control card (gure 13).
Terminals 1-2-3, terminal board M2: connections for a zone control solenoid valve (see gure 15 in section 15.4).
15.2 CONNECTING THE QAA73 TEMPERATURE REGULATOR
0403_2502
Screw
Figure 13
Cable guide
LEGEND:
N.C. - Normally Closed contacts
C - Common
N.O. - Normally Open contacts
WIRE COLOURS:
M Brown
N Black
C Light blue
R Red
Domestic hot water temperature and timing must be programmed on the QAA73 temperature regulator.
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.
See the instructions provided with the QAA73 temperature regulator for the user parameter programming procedure.

15 925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE INSTALLER
QAA73: parameters which can be set by the installer (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:
Line no.
70
72
74
75
77
78
79
90
91
Default value
15
80
Light
On HC1
On
0
0
35
24 h/day
Range
2.5…40
25…80
Light, Heavy
on HC1
on HC2
on HC1+HC2
nil
On - off
0…360 min
0…360 min
10 or 35
24 h/day
TSP HC-1h
TSP HC
TSP DHW
Parameter
HC1 gradient
Selection of central heating circuit temperature curve “kt”
HC1 max. output
Central heating system maximum output temperature
Type of building
Room compensation
Activation/deactivation of the inuence of the room temperature. If it is
deactivated, the outdoor temperature sensor must be installed.
Automatic adaptation of the temperature curve “kt” in relation to the room
temperature.
Opt Start Max
Maximum time the boiler is switched on ahead of the timed program to
optimise the temperature in the premises.
Opt Stop Max
Maximum time the boiler is switched off ahead of the timed program to
optimise the temperature in the premises.
DHW Red Setp
Minimum temperature of the domestic domestic hot water
DHW program
Selection of the type of timed program for domestic hot water.
24 h/day = always on
PROG HC-1h = as HC1 central heating program less one hour
PROG HC = as central heating program
PROG ACS = specic domestic hot water program
(see also program lines 30-36)
- fault messages
In the event of fault, the display panel on the QAA73 shows the ashing symbol . Press the information key ( ) to display
the error code and a description of the fault (see errors table in section 3.3.1).

16 925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE INSTALLER
15.3 CONNECTING THE OUTDOOR TEMPERATURE SENSOR PROBE
The SIEMENS model QAC34 outdoor temperature sensor probe (optional accessory) must be connected to terminals 5-6
of terminal board M2 in gure 12.
The procedures for setting the gradient of the temperature curve “kt” vary depending on the accessories connected to
the boiler.
0806_0802 / CG_1819
Figure 14
a) Without the QAA73 temperature regulator
When an outdoor temperature sensor is connected, the central heating
temperature control knob (g. 14) shifts the heating curves (graph 2).
Turn the knob clockwise to increase room temperature, anti-clockwise
to decrease it. Figure 14 shows the correct position of the knob for
operation without shifting the curves.
Modify parameter 532 on the QAA73 temperature regulator to select the desired temperature curve “Kt”, as instructed
in chapter 26.
Graph 1 shows the available temperature curves.
TM = Flow temperature
Te = Composite outside temperature
Graph 1
Graph 2
0409_1601
0410_0802

17 925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE INSTALLER
b) with QAA73 temperature regulator:
The temperature curve “kt” must be selected by setting parameter 70 “HC1 gradient” of the QAA73 temperature control
device as described in section 15.2 “QAA73: parameters which can be set by the installation engineer (service)”.
See graph 3 for selecting the curve referred to a room temperature of 20°C.
The curve is shifted automatically on the basis of the room temperature set using the QAA73 climate control.
If the central heating system is divided into more than one zone, the temperature curve must be set on the QAA73 and in
the boiler (See section 26 for boiler settings.). The appliance’s electronic control system provides a central heating output
temperature equal to the highest of the two values set on the QAA73 and in the boiler.
Graph 3
TM = Flow temperature
Te = Composite outside temperature
0403_2504
The electrical connections and settings needed to control a multi-zone central heating system vary depending on what acces-
sories are connected to the boiler.
To permit the boiler to handle requests from individual zones, turn the Summer/Winter selector (1 - gure 1) on the boiler’s front
panel to Winter ( ) position.
a) Without a QAA73 temperature regulator:
Connect the switch for functioning in multi-zone mode in parallel to the “TA” terminals 1-2 on terminal board M1 as shown in
gure 12. Remove the default bridge.
Set the desired temperature with knob 6, gure 1, directly on the boiler control panel.
b) With the QAA73 temperature regulator:
Connect the switch controlling those zones not controlled by the QAA73 in parallel to the “TA” terminals 1-2 of terminal board
M1 as shown in gure 15. Remove the default bridge.
The zone controlled by the QAA73 is supplied by the zone 1 solenoid valve as shown in gure 15.
The QAA73 automatically controls room temperature in its own zone.
15.4 ELECTRICAL CONNECTIONS TO A MULTI-ZONE SYSTEM

18 925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE INSTALLER
Figure 15
0402_25010
N Zone
(ROOM
THERMOSTAT)
3 Zone
(ROOM
THERMOSTAT)
2 Zone
(ROOM
THERMOSTAT)
1 Zone
(QAA 73)
solenoid
valve 1 Zone
Case 1: installation without an outdoor temperature sensor:
Use the central heating temperature control knob (6 - gure 1) on the boiler’s control panel to set central heating output
temperature to the various zones.
If heating requests are received simultaneously from the main zone controlled by the QAA73 and another zone, output tempe-
rature will be the higher of the two values set on the QAA73 and on the boiler’s central heating temperature control knob.
Case 2: installation with an outdoor sensor:
Central heating output temperature to the various zones is determined by the electronic control card on the basis of outdoor
temperature and the preset heating curve as described in section 15.3.
If heating requests are received simultaneously from the main zone controlled by the QAA73 and another zone, output tem-
perature will be the higher of the values set on the QAA73 and calculated by the boiler’s electronic control card.
Use the boiler control panel to set room temperature in the other zones.
1 Zone
(ROOM
THERMOSTAT)
Boiler models NOVADENS 1.240 feature a three way power valve for connecting an external boiler.
Connect the boiler water pipes as shown in gure 16.
Remove the resistor from terminals 9-10 of terminal board M2, and connect the optional DHW priority sensor
to them (gure 16).
Insert the sensor’s probe in the relevant hole in the boiler.
Set domestic hot water temperature using the control knob 7, gure 1 on the boiler’s front panel.
15.5 CONNECTING AN EXTERNAL BOILER (NOVADENS 1.240)

19 925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE INSTALLER
16. GAS CHANGE TYPE
Proceed as follows to calibrate the gas valve.
1) Calibrate maximum thermal power. With the boiler operating at
maximum thermal power, check that the value for CO2measured in
the ue corresponds to that specied in table 1. If necessary, turn
the adjuster screw (V) on the gas valve. Turn clockwise to reduce
the CO2level or anti-clockwise to increase it.
2) Calibrate minimum thermal power. With the boiler operating at
minimum thermal power, check that the value for CO2measured in
the ue corresponds to that specied in table 1. If necessary, turn
the adjuster screw (K) on the gas valve. Turn clockwise to increase
the CO2level or anti-clockwise to reduce it.
0310_0114
Figure 17
Pi: Gas supply pressure measurement point
P out: Gas feed to burner pressure measurement
point
P: Offset pressure measurement point
Pl: Air signal input from fan
V: Gas ow adjustment screw
K: Offset adjustment screw
Figure 16
0402_2511
UB: DHW boiler unit
UR: central heating unit
V3V: three way valve
M2: terminal board
SB: DHW priority sensor
MR: central heating delivery
MB: DHW delivery
RR: central heating/DHW return
RB: resistor, to be removed
NOTE: legionella function is active (factory set = ON; see section 26 parameter 555.1).
LEGEND

20 925.477.3 - GB
INSTRUCTIONS PERTAINING TO THE INSTALLER
16.1 ACTIVATING THE CALIBRATION FUNCTION
Proceed as follows to enter “calibration function” on the boiler control panel and calibrate the gas valve.
1) Turn the control knobs 6 and 7 (gure 1) fully anti-clockwise to their minimum positions as shown in gure 18A.
2) Starting in this position, quickly turn control knob 7 twice consecutively clockwise through about a 1/4turn as shown
in gure 18B.
NOTE: LEDs 2 and 3 (figure 1) flash alternately and the display alternates the message “SF” and the boiler output
temperature about every five seconds (figure 19).
3) Now turn knob 6 to adjust fan speed to a setting between minimum thermal power (0%) and maximum thermal power
(100%).
NOTE: In “calibration function”, the display alternates between the message “P” and the boiler output tempe-
rature about every 5 seconds (figure 20).
4) Calibration function remains active for 20 minutes. To exit “calibration function” before this time simply turn control
knob 7 (gure 1).
NOTE: This function is interrupted if the central heating delivery temperature reaches its MAX. SETPOINT.
0806_0104 / CG_1820
Figure 18B
Figure 19
0402_2513
~ 5 seconds
Figure 18A