Bosch CFB 840 User guide

Servicing instructions for heating contractors
Control Unit
CFB 840
6 720 803 855-00.1T
6 720 802 836 (2012/05) GB/IE/AU

2| Table of contents
CFB 8406 720 802 836 (2012/05)
Table of contents
1 Key to symbols and safety instructions . . . . . . . . . . . . . . . . . . . 4
1.1 Key to symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Safety regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Product information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1 Determined use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 EU Declaration of Conformity . . . . . . . . . . . . . . . . . . . . . 4
2.3 Notes on commissioning . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.4 Cleaning the control unit . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.5 Product description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.6 Scope of supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.7 Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.7.1 Controller CFB 840 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.7.2 FM442/CMM 920 function module . . . . . . . . . . . . . . . . . 5
3 Setting instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1 Setting instructions and replacement instructions
for high limit safety cut-out (STB) . . . . . . . . . . . . . . . . . . 5
3.1.1 Setting and installation of the high limit safety cut-out . 5
3.1.2 Adjusting the high limit safety cut-out . . . . . . . . . . . . . . . 6
3.2 Setting instructions for boiler water thermostat (TR) . . 6
4 Controls and programming unit . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.1 Control unit controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.2 Programmer programming unit . . . . . . . . . . . . . . . . . . . . 8
5 Modules and their function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.1 CM431 controller module . . . . . . . . . . . . . . . . . . . . . . . . 9
5.2 NM482 power supply module . . . . . . . . . . . . . . . . . . . . 10
5.3 Central module ZM422 . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.3.1 Burner function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.3.2 Heating circuit and DHW functions . . . . . . . . . . . . . . . . 11
5.4 FM442/CMM 920 function module (accessory) . . . . . 11
6 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6.1 Commissioning the programming unit . . . . . . . . . . . . . 12
6.1.1 New Programmer installed in a control unit . . . . . . . . . 12
6.1.2 Programmer is installed in another control unit . . . . . . 12
6.1.3 Programmer with set parameters installed
in control unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6.2 Checking the high limit safety cut-out (STB) . . . . . . . . . 13
6.2.1 Triggering the high limit safety cut-out . . . . . . . . . . . . . 13
6.2.2 Terminating or cancelling the test . . . . . . . . . . . . . . . . . 13
6.2.3 Resetting the high limit safety cut-out . . . . . . . . . . . . . . 14
7 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
7.1 Adjustable parameters and display data . . . . . . . . . . . . 15
7.2 Calling up the service level . . . . . . . . . . . . . . . . . . . . . . . 16
7.2.1 Control system "Press and turn" . . . . . . . . . . . . . . . . . . 16
7.2.2 Calling up main menus . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7.2.3 Calling up submenus . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7.3 Calling up and modifying settings . . . . . . . . . . . . . . . . . 16
8 General specification data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
8.1 Minimum outside temperature . . . . . . . . . . . . . . . . . . . 17
8.2 Type of building . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
8.3 Summer/wintertime changeover . . . . . . . . . . . . . . . . . 18
8.4 Remote adjust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
8.5 Manual fault message control . . . . . . . . . . . . . . . . . . . . 19
8.6 Automatic maint. message . . . . . . . . . . . . . . . . . . . . . . 19
8.7 Module selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
9 Boiler parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
9.1 Select boiler type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
9.1.1 Low temperature boilers . . . . . . . . . . . . . . . . . . . . . . . . 20
9.1.2 Ecostream boilers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
9.1.3 Condensing boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
9.1.4 Low-temperature boilers with base temperature . . . . . 21
9.2 Setting the burner type . . . . . . . . . . . . . . . . . . . . . . . . . 22
9.2.1 Modulating burner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
9.2.2 2 x single stage burner . . . . . . . . . . . . . . . . . . . . . . . . . . 22
9.3 General settings regarding boiler parameters . . . . . . . 23
9.3.1 Set up the pump function . . . . . . . . . . . . . . . . . . . . . . . 23
9.3.2 Setting boiler pump run-on time . . . . . . . . . . . . . . . . . . 23
9.3.3 Setting the minimum burner runtime . . . . . . . . . . . . . . 23
9.3.4 Selecting the minimum start temperature . . . . . . . . . . 23
9.3.5 Selecting the maximum shutdown temperature . . . . . 24
9.3.6 Setting the maximum flue gas temperature limit . . . . . 24
10 Heating circuit data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
10.1 Adjusting the heating system . . . . . . . . . . . . . . . . . . . . . 24
10.2 Rename the heating circuit . . . . . . . . . . . . . . . . . . . . . . 25
10.3 Setting the low end temperature . . . . . . . . . . . . . . . . . . 25
10.4 Setting the design temperature . . . . . . . . . . . . . . . . . . . 25
10.5 Setting the Minimum flow temperature . . . . . . . . . . . . 26
10.6 Setting the maximum flow temperature . . . . . . . . . . . . 26
10.7 Select the remote control . . . . . . . . . . . . . . . . . . . . . . . 26
10.8 Maximum room influence setting . . . . . . . . . . . . . . . . . 27
10.9 Select the type of setback . . . . . . . . . . . . . . . . . . . . . . . 27
10.10 Setting the outside stop temperature . . . . . . . . . . . . . . 28
10.11 Setting holiday mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
10.12 Stopping setback at low outside temperatures . . . . . . 28
10.13 Setting flow setback . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
10.14 Setting the room temperature offset . . . . . . . . . . . . . . 29
10.15 Automatic adaptation setting . . . . . . . . . . . . . . . . . . . . 29
10.16 Setting switching optimisation . . . . . . . . . . . . . . . . . . . 30
10.17 Set switch off optimisation time . . . . . . . . . . . . . . . . . . 30
10.18 Setting frost protection temperature . . . . . . . . . . . . . . 31
10.19 Setting DHW priority . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
10.20 Setting the heating circuit actuator . . . . . . . . . . . . . . . . 31
10.21 Set the actuator run-time . . . . . . . . . . . . . . . . . . . . . . . . 32
10.22 Setting the Boiler raising . . . . . . . . . . . . . . . . . . . . . . . . 32
10.23 Setting the external changeover . . . . . . . . . . . . . . . . . . 32
10.24 External fault message - pump . . . . . . . . . . . . . . . . . . . . 33
10.25 Screed drying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
10.25.1 Setting the temperature rise . . . . . . . . . . . . . . . . . . . . 34
10.25.2 Setting the heat-up time . . . . . . . . . . . . . . . . . . . . . . . . 34
10.25.3 Setting the maximum temperature . . . . . . . . . . . . . . . 34
10.25.4 Setting the hold time . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
10.25.5 Setting the setback temperature . . . . . . . . . . . . . . . . . 35
10.25.6 Setting the setback time . . . . . . . . . . . . . . . . . . . . . . . . 35

Table of contents | 3
6 720 802 836 (2012/05)CFB 840
11 DHW data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
11.1 Select Domestic hot water . . . . . . . . . . . . . . . . . . . . . . . 35
11.2 Setting the temperature range . . . . . . . . . . . . . . . . . . . 35
11.3 Selecting switching optimisation . . . . . . . . . . . . . . . . . 36
11.4 Selecting residual heat use . . . . . . . . . . . . . . . . . . . . . . 36
11.5 Setting hysteresis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
11.6 Raising the boiler temperature . . . . . . . . . . . . . . . . . . . 37
11.7 External fault indication (WF1/WF2) . . . . . . . . . . . . . . 37
11.8 External contact (WF1/WF3) . . . . . . . . . . . . . . . . . . . . 37
11.9 Thermal disinfection . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
11.9.1 Setting thermal disinfection . . . . . . . . . . . . . . . . . . . . . 38
11.9.2 Setting the temperature . . . . . . . . . . . . . . . . . . . . . . . . 38
11.9.3 Setting the weekday . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
11.9.4 Setting the time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
11.10 Setting range Daily heat-up . . . . . . . . . . . . . . . . . . . . . . 39
11.11 DHW circulation pump . . . . . . . . . . . . . . . . . . . . . . . . . . 40
11.11.1 Selecting the DHW circulation pump . . . . . . . . . . . . . . 40
11.11.2 Setting intervals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
12 Special parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
13 Heating curve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
14 Relay test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
15 Carrying out an LCD test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
16 Fault log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
17 Monitor data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
17.1 Boiler monitor data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
17.2 Heating circuit monitor data . . . . . . . . . . . . . . . . . . . . . 43
17.3 DHW monitor data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
18 Display version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
19 Selecting the control unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
20 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
21 Environment / disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
22 Faults and fault remediation . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
23 Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
23.1 Sensor curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
23.2 Setting specific boiler data . . . . . . . . . . . . . . . . . . . . . . 50
Keyword index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

4| Key to symbols and safety instructions
CFB 8406 720 802 836 (2012/05)
1 Key to symbols and safety instructions
1.1 Key to symbols
Warnings
Keywords at the start of a warning indicate the type and severity of the
ensuing risk if measures to prevent the risk are not taken.
•NOTE indicates that material losses may occur.
•CAUTION indicates possible minor to medium personal injury.
•WARNING indicates possible severe injury.
•DANGER indicates that severe personal injury may occur.
Important information
Additional symbols
1.2 Safety regulations
General safety instructions
Failure to observe the safety instructions can result in serious injuries
and a risk to life as well as material losses and damage to the
environment.
BEnsure that only a qualified contractor carries out installation,
connection of exhaust system, commissioning, maintenance and
service.
BCarry out maintenance at least once a year. As part of this, check that
the entire system is working correctly. Immediately remedy all defects
found.
BRead the safety instructions carefully prior to commissioning the
system.
Original spare parts
Losses caused by the use of spare parts not supplied by the
manufacturer are excluded from the manufacturer's warranty.
BUse only original spare parts and accessories from the manufacturer.
Risk of scalding
There is a risk of scalding if the required DHW temperature is set higher
than 60 °C.
BDo not draw off DHW unmixed.
Damage due to operator error
Operator errors can result in injury and damage to property.
BEnsure that children never operate this appliance unsupervised or
play with it.
BEnsure that only personnel who can operate this appliance correctly
have access to it.
BInstallation and commissioning as well as servicing and maintenance
must only be carried out by a qualified contractor.
BBefore unpacking the device touch a radiator or an earthed metal
water pipe to discharge any electrostatic charge in your body.
Risk of death from electric shock
BEnsure that any electrical work is only carried out by an approved
electrician.
BObserve the relevant requirements when working on electrical
installations.
BEnsure that a circuit breaker in accordance with applicable standards
is present to disconnect all poles from the mains power supply. If
there is no circuit breaker, you will need to install one.
BBefore opening the control unit, isolate all poles of the heating system
via the circuit breaker. Secure against unintentional reconnection.
System damage through frost
When the heating system is switched off, it can freeze up if there is frost.
BProtect your heating and water system against freezing by draining
the heating system and hot water pipes at the lowest point.
2 Product information
These service instructions contain important information on the safe and
appropriate commissioning and servicing of the CFB 840 control unit.
These service instructions are designed for heating contractors, who,
due to their vocational training and experience, –are knowledgeable in
handling heating systems and water installations. Only carry out
servicing if you have such specialist knowledge and skills.
Explain to the customer the function and operation of the appliance.
2.1 Determined use
The CFB 840 control unit is designed to control heating systems in
detached houses, apartment buildings, residential complexes and other
buildings.
2.2 EU Declaration of Conformity
The design and operation of this product conforms to the European
Directives and the supplementary national requirements. Its conformity
is confirmed by the CE designation.
You can view the Declaration of Conformity on the internet or request a
copy from your local office.
Warnings in this document are framed and identified by
a warning triangle printed against a grey background.
Important information in cases where there is no risk of
personal injury or material losses is identified by the
symbol shown on the left. It is bordered by horizontal
lines above and below the text.
Symbol Meaning
Ba step in an action sequence
Æa reference to a related part in the document or to other
related documents
•a list entry
–a list entry (second level)
Table 1

Setting instructions | 5
6 720 802 836 (2012/05)CFB 840
2.3 Notes on commissioning
BBefore switching the control unit on, check that its manual switches
and those on the function modules are set to AUT.
BEnter the settings made during commissioning and the allocation of
the heating circuits into the commissioning report in the operating
instructions of the control unit.
BSwitch on the control unit first and then the boiler.
BTo shut down, switch off the boiler first and then the control unit.
BEnsure that there is sufficient heat load, otherwise the boiler will
switch off and generate a fault condition.
2.4 Cleaning the control unit
BOnly clean the control unit with a damp cloth.
2.5 Product description
The digital CFB 840 control unit is suitableforregulating a floor-standing
oil/gas-fired boiler with single stage, two-stage or modulating burner.
As standard, the unit includes the DHW heating (cylinder system) and
heating circuitcontrol (one heating circuit without actuator) functions. It
can be expanded by adding up to two function modules to suit the
requirements of the heating system.
2.6 Scope of supply
Included in the standard delivery:
•Digital CFB 840 control unit with programming unit
•FA outside temperature sensor
•Boiler water temperature sensor FK
2.7 Technical data
2.7.1 Controller CFB 840
2.7.2 FM442/CMM 920 function module
3 Setting instructions
3.1 Setting instructions and replacement instructions for
high limit safety cut-out (STB)
3.1.1 Setting and installation of the high limit safety cut-out
To be able to set the temperatures, the high limit safety cut-out (STB)
must be removed from the control unit housing.
BUndo screws [1].
BRemove cover [2].
BRemove protective cap [3].
BUndo the screw connection.
BRemove the STB with its assembly plate and make the adjustments
(Æchapter 3.1.2).
DANGER: Risk to life and of system damage through
excessively high temperatures.
All parts directly or indirectly subject to high
temperatures must be designed for use at such
temperatures.
BEnsure that wiring and other lines are routed at a safe
distance from hot boiler parts.
BRoute wiring and other lines, in the wiring ducts
provided or above the boiler insulation.
Unit CFB 840
Dimensions B/H/L mm 460/240/230
Operating voltage (at 50 Hz ±4 %) V 230 ±10 %
Power consumption VA 5
Control unit fuse A 10
Maximum switching current
•Burner output
•Boiler or heating circuit pump
output
A8
5
Boiler circuit actuator control V 230
Servomotor runtime, burner
modulating
sec 120
(adjustable from 5 to
60)
Type of controller - burner and
heating circuit actuator
Three-point stepper
controller (PI
characteristics)
Ambient temperatures
•Operation
•Transport °C +5...+50
–20...+55
Table 2 Specification - CFB 840 control unit
Sensor
lower fault
limit in °C
smallest
display value
in °C
highest
display value
in °C
upper fault
limit in °C
FA –50 –40 50 > 70
FK < –5 0 > 108 > 125
FB < –5 099> 125
Table 3 Sensor measuring range
Unit Value
Operating voltage (at 50 Hz ±4%) V 230 ±10 %
Power consumption VA 2
Maximum switching current - heating
circuit circulation pump output
A 5
Heating circuit actuator control V 230
Servomotor runtime sec 120 (adjustable
10 – 600)
Type of controller – Three-pointstepper
controller (PI
characteristics)
Table 4 Technical data for FM442/CMM 920 function module
Sensor
lower
fault
limit
in °C
smallest
display
value
in °C
highest
display
value
in °C
upper fault limit
in °C
FV1 flow temp. HC
on left
< –5 099125
FB flow temp. HC
on right
< –5 099125
Table 5 Sensor measuring range
DANGER: Risk to life from electric shock!
BBefore opening the control unit, isolate all poles of the
control unit and secure against unauthorised re-
connection.

6| Setting instructions
CFB 8406 720 802 836 (2012/05)
Fig. 1 Remove the high limit safety cut-out
[1] Screws
[2] Cover
[3] STB protective cap
3.1.2 Adjusting the high limit safety cut-out
Version A
BUndo the screw [3].
BAdjust the temperature scale [2] to setting [1].
BRe-tighten screw [3].
Fig. 2 Adjusting the high limit safety cut-out (STB) - variant A
[1] Marking
[2] Temperature scale
[3] Screw
BInstall STB into housing.
BCheck the high limit safety cut-out (Æchapter 6.2, page 13).
Version B
BSet the temperature using a screwdriver.
Fig. 3 Adjusting the high limit safety cut-out (STB) - variant B
BInstall STB into housing.
BCheck the high limit safety cut-out (Æchapter 6.2, page 13).
3.2 Setting instructions for boiler water thermostat (TR)
For systems requiring a boiler water temperature higher than 90 °C
(observe the relevant notice), the boiler temperature controller setting
can be changed from 90 °C to 105 °C.
BPull off rotary dial.
BBreak off the end stop tabs [1].
Set the high limit safety cut-out in accordance with local
regulations, applicable standards and the boiler
certificate to the maximum permissible heating system
temperature.
The factory setting is 110 °C.
CAUTION: System damage due to incorrect installation
of the STB at the boiler!
The sensor must be pushed into the sensor well as far as
possible to ensure areliable and fast shutdown in case of
excesstemperature. Ensure an optimum heat transfer
from STB sensor to boiler. The sensors must be secured
in the sensor wells by means of the sensor locks
(standard delivery). The capillaries must not be
damaged or kinked.
BVerify the function of the STB before commissioning.
BRegular checks must be performed in accordance
with the boiler manufacturer's specifications.
DANGER: Risk to life and of system damage through
incorrect shutdown of the STB.
BEnsure that the STB is correctly shut down before
commissioning the boiler.
Special regulations and standards apply to boilers with
an STB setting of 120 °C. Boilers installed with an STB
setting higher than 110C have to meet specific
requirements.
1 1
3 2 6 720 803 704-03.1T
Changing the boiler temperature controller from 90 °C to
105 °C (STB setting 120 °C only).
Control units may be operated with a maximum flow
temperature of 99 °C (Æchapter 9.3.5, page 24).
3
6 720 803 704-01.1T
120
100
110
1
2
6 720 803 704-12.1T
120
110
100
°C

Controls and programming unit | 7
6 720 802 836 (2012/05)CFB 840
BReposition rotary dial.
Fig. 4 Boiler water temperature controller
[1] End stop tabs
4 Controls and programming unit
4.1 Control unit controls
Fig. 5 Control unit controls (delivered condition)
[1] High limit safety cut-out
[2] Boiler water temperature controller
[3] Fuse F1
[4] Connection for external service equipment and programmer
[5] Burner emergency operation switch
[6] On/Off switch
Fig. 6 Fitted modules
[1] Slot 1, e.g. FM442/CMM 920 - heating circuit 1, heating circuit 2
[2] Slot A: ZM422 - feed for external heat sources, heating circuit 0
[3] Slot B: Programmer (CM431) - programming unit
[4] Slot 2, e.g. FM442/CMM 920 - heating circuit 3, heating circuit 4
1
6 720 803 704-04.1T
1 2 3 4 5 6 6 720 803 704-05.1T
1 2 3 4
6 720 803 704-06.1T

8| Controls and programming unit
CFB 8406 720 802 836 (2012/05)
4.2 Programmer programming unit
Fig. 7 Programmer programming unit
[1] Radio clock signal (only in Germany)
[2] Display for set room temperature
[3] Input DHW temperature/heating
[4] Setting the time
[5] Change temperature values
[6] Summer/wintertime changeover
[7] Back to the standard display
[8] Select a time switch program
[9] Selecting heating circuits/DHW circuit
[10] Select standard display
[11] Enter holidays
[12] Enter the day of the week
[13] Constant setback mode
[14] Automatic heating mode in accordance with a time switch
[15] Constant heating mode
[16] Rotary dial
[17] Display
1
2
3
5
6
7
9 8
4
10
11
12
13
14
15
16
17
6 720 803 703-04.1T

Modules and their function | 9
6 720 802 836 (2012/05)CFB 840
5 Modules and their function
All modules which are or can be fitted into your CFB 840 control unit are
shown here.
The following pages contain information regarding the most important
modules you can use.
[O] Standard equipment
[X] Optional equipment
[ – ] Combination not possible
5.1 CM431 controller module
Setting the control unit address
The address settings [1] for the CFB 840 control unit are made on the
CM431 module (behind the programming unit).
BRemove the programming unit.
BYou can now set the control unit address using a screwdriver or similar
tool.
Fig. 8 Address setting
[1] Address setting
Module CFB 840
Programmer O
CM431 controller module O
Central module ZM422 – burner control,
1 heating circuit + 1 DHW circuit
O
Function module FM441/CMM 910 –
1 heating circuit + 1 DHW circuit
–
Function module FM442/CMM 920 - 2 DHW circuits X
Function module FM443/CMS 910 – solar circuit X
Function module FM444/CMG 910 –
alternative heat source
X
Function module FM445/CML 910 –
LAP/LSP (primary store system)
X
Function module FM448/CMB 930 –
central fault message
X
Expansion module ZM426/CME 920 – additional STB X
Function module FM458/CMC 930 – strategy module –
Table 6 Modules and their functions
16 720 803 703-05.1T
Address Description
0 Stand-alone control unit:
Set the address to 0 if the control unit operates as stand-
alone equipment (factory setting).
Each device must be given a different address if several
devices connected to the networked. A fault message is
displayed in the Programmer display if the same address is
allocated more than once.
1Master(leadcontrolunit):
Address 1 is a special setting since the device with this
address acts as the master device. The master controls the
boiler.
The ambient temperature sensor must always be connected
to the master.
The master monitors the ECOCAN BUS, which links the
control units.
The master recognises if an address has been allocated
more than once. A fault message is displayed by the
Programmer display.
All networked control units transfer their set values to the
master, which uses them to formulate the overall
temperature setpoint.
Any network must only include one master.
2 – 15 Not applicable to CFB 840 control unit
Table 7 Control unit addresses

10 | Modules and their function
CFB 8406 720 802 836 (2012/05)
5.2 NM482 power supply module
End connection when networking several control units
To ensure fault free data transmission between several control units, fit
the end connections to the two control units which are furthest apart.
The end connection is fitted to the component side of the NM482 power
supply module, and is activated by the gravity switch (fig. 9, [2]).
Fig. 9 NM482 power supply module
[1] ECOCAN BUS
[2] Gravity switch S1 (for end connection)
factory setting: open
The factory setting is: Gravity switch S1 open = end connection not
fitted.
Fig. 10 Example of a fitted end connection, in case of several control
units
5.3 Central module ZM422
The ZM422 module is part of the basic equipment of the CFB 840
control unit. The manual switches on the module are only provided for
service and maintenance functions.
If the manual switches are not set to automatic, a corresponding
message appears on the programming unit and the fault indicator
illuminates.
The control functions remain operational in manual mode without any
restrictions.
Fig. 11 ZM422
[1] General fault,
e.g. on-site faults, sensor faults, external faults, wiring faults,
internal module faults, manual mode. The error messages appear
as plain text in the programming unit.
[2] Boiler circuit 0 in summer mode
[3] Heating circuit 0 or boiler pump operational
[4] DHW circulation pump operational
[5] Cylinder primary pump operational
[6] Manual switch heating circuit and DHW
[7] Manual burner switch
[8] Modulating output is reduced
[9] Modulation output is increased/2nd stage operation
[10] Burner in operation
[11] "Flue gas test" button
[12] Burner fault
DANGER: Risk to life from electric shock!
BEnsure that all electrical work is only carried out by a
competent person.
BBefore opening the control unit, isolate all poles of the
control unit and secure against unauthorised re-
connection.
1
2
6 720 803 703-06.1T
Widerstand
einlegen
Widerstand
einlegen
Gerät
4... Gerät 4...
Gerät
4... Gerät
4... Gerät
4...
6 720 803 703-07.1T
Fitting the
end connection
Fitting the
end connection
Device
4...
Device
4...
Device
4...
Device
4...
Device
4...
Device
4...
Never use the manual switch to shut down the heating
system during temporary absence. Use the holiday
function for this purpose (Æoperating instructions for
control unit).
1
2
3
4
5
6
9
8
7
6 720 803 704-07.1T
10
11
12

Modules and their function | 11
6 720 802 836 (2012/05)CFB 840
5.3.1 Burner function
Flue gas test
BPress and hold button Flue gas test (Æfig. 11, [11], page 10) for a
few seconds.
The heating control unit operates for 30 minutes at a higher flow
temperature.
During the flue gas test, the indicators Fault and Summer mode flash
alternately.
To terminate the flue gas test:
BPress button Flue gas test again.
Manual burner switch
Positions 0, Manual and max I + II of the burner's manual switch are
special settings (Æfig. 11, [7], page 10) reserved for contractors.
The burner may be directly controlled with the manual switch.
5.3.2 Heating circuit and DHW functions
Positions 0and Manual are special settings of the manual switch for the
heating circuit and DHW (Æfig. 11, [6], page 10) reserved to
contractors.
5.4 FM442/CMM 920 function module (accessory)
The FM442/CMM 920 module regulates two independent heating
circuits with optional mixing valves. Several of these modules can be
used in one control unit.
The manual switches on the module only have service and maintenance
functions and only affect 230 V outputs.
If the manual switches are not set to automatic, a corresponding
message appears on the programming unit, and the corresponding
indicator Fault illuminates.
The control functions remain operational in manual mode without any
restrictions.
Fig. 12 FM442/CMM 920
[1] General fault,
e.g. on-site faults, sensor faults, external faults, wiring faults,
internal module faults, manual mode. The error messages appear
as plain text in the programming unit.
[2] Heating circuit in summer mode
[3] Heating circuit pump operational
[4] "Mixing valve opens" (hotter)
[5] "Mixing valve closes" (colder)
[6] Manual heating circuit switch
e.g. for heating circuit 1 and 2
In normal operation, the manual switch is set to AUT.
Current functions are indicated by LEDs.
Position Function
As base load, only the first stage will be
enabled for single and two stage burners. The
second stage is at zero volts. The burner
servomotor cannot be reversed. For
modulating burners, the burner output can be
increased using Sand reduced using T.
The burner operates in automatic mode.
The burner is switched OFF. Except when the
burner emergency switch is set to Manual.
The burner operates continuously at maximum
output.
Table 8 Burner functions ZM422
In normal operation, the manual switch is set to AUT.
Current functions are indicated by LEDs.
AUT
0
max
I+II
AUT
0
max
I+II
AUT
0
max
I+II
AUT
0
max
I+II
Position Function
The heating circuit 0 pump or boiler pump and
the cylinder primary pump are switched on.
Heating circuit 0 pump or the boiler circuit and
DHW circuit operate in automatic mode.
Heating circuit 0 pump or boiler pump, the
cylinder primary pump and DHW circulation
pump are switched off. The control functions
remain active.
Table 9 Heating circuit and DHW functions ZM422
Never use the manual switch to shut down the heating
system during temporary absence. Use the holiday
function for this purpose (Æsee operating instructions
for control units).
1
3
4
5
6
2
6 720 803 703-13.1T

12 | Commissioning
CFB 8406 720 802 836 (2012/05)
Heating circuit function
Positions 0and Manual are special settings of the manual switch for the
heating circuit (Æfig. 12, page [6]) reserved to contractors.
6 Commissioning
6.1 Commissioning the programming unit
The programming unit can be used with all control units of the series 7xx,
8xx and 9xx.
The programming unit can be used as follows:
•directly in the control unit
•wall-mounted as remote control unit or
•in an adapter with separate power source.
The Programmer starts the initialisation process as soon as supply
voltage is connected. The display shows MEC is initialised.
The control unit address is then briefly displayed.
The display shows Connection with ctrl. unit Address xx established.
Depending on the individual application, the display shows various
information:
6.1.1 New Programmer installed in a control unit
If a brand new Programmer has been installed in the control unit and the
connections with the control unit have been established, data are
immediately downloaded from the control unit.
The display shows Monitor data will from ctrl unit taken.
6.1.2 Programmer is installed in another control unit
If the Programmer is programmed with a software version that is not able
to recognise this type of control unit, the display shows Unknown
control unit.
BRemove the Programmer from the control unit and replace by a
Programmer with a suitable software version.
6.1.3 Programmer with set parameters installed in control unit
After the Programmer has been installed in the control unit, the two
adjacent displays will initially be re-displayed. MEC is initialised or
Connection with ctrl. unit Address xx established.
Alternative control unit type
Initially, only data from the control unit can be downloaded, if the type of
control unit varies from that entered in the programming unit. The
display shows Other Ctrl. unit type, Night button receive.
BPress the Night mode button.
The display shows Data are from ctrl unit taken.
Alternative control unit of the same type
If the Programmer is connected to a different control unit of the same
type, the display will show the below message for approx. 3 seconds.
NB other control unit.
If the Programmer programming unit is separated from the control unit
and data is modified, the display shows Aut button transmit, Night
button receive, when the unit is reinstalled into a control unit of the
same type. The control unit scans whether the new data should be
accepted or whether the old data from the control unit should be used
again.
To adopt the new data:
BPress AUT.
The display shows Data are to ctrl unit sent.
To adopt the data from the control unit:
BPress the Night mode button.
The display shows Data are from ctrl unit taken.
Identical control unit
If the programming unit is separated from the control unit and data is
modified externally, the display shows Aut button transmit, Night
button receive, when the unit is reinstalled into a control unit of the
same type. The control unit scans whether the new data should be
accepted or whether the old data from the control unit should be used
again.
To adopt the new data:
BPress AUT.
The display shows Data are to ctrl unit sent.
To adopt the data from the control unit:
BPress the Night mode button.
The display shows Data are from ctrl unit taken.
In normal operation the manual switch should be in the
AUT position.
Current functions are indicated by LEDs.
Position Function
The heating circuit pump is switched on. The
mixing valve is switched volt-free and can be
manually operated.
The central heating or the DHW circuit
operates in automatic mode.
The heating circuit pump is switched off. The
mixing valve is switched volt-free. The control
functions remain active.
Table 10 Heating circuit functions FM442/CMM 920
If the Programmer is fitted in the control unit or wall
mounting plate, it automatically detects the control unit
to which it is connected (automatic detection). You do
not have to select the control unit.

Commissioning | 13
6 720 802 836 (2012/05)CFB 840
6.2 Checking the high limit safety cut-out (STB)
The boiler temperature must be monitored continuously at the
programmer or at the boiler display of the ZM435 or at suitable
measuring points while performing the STB check.
The burner must shut down automatically when the set cut-out
temperature (chapter 3) of the STB + 2K (example 110 °C + 2K =
112 °C) is reached. If the burner does not shut down at this point,
manually interrupt the checking procedure at once. To shut down,
release the lever of button and switch the emergency mode switch of the
burner to AUT.
After interrupting the checking procedure, check the correct routing of
the capillaries and the temperature sensor head as well as the assembly
and wiring of the boiler water temperature sensor. When in doubt,
assume the STB to be broken. In this case the broken high limit safety
cut-out must be replaced.
6.2.1 Triggering the high limit safety cut-out
BSet burner emergency switch [2] Manual.
The burner starts.
BPull off the thermostat selector dial [1].
BDepending on the type of controller, push the lever or button
(Æfig. 14) back with a screwdriver or similar tool and hold until
the high limit safety cut-out has triggered.
BContinuously monitor the boiler temperature, and interrupt the test,
if required.
6.2.2 Terminating or cancelling the test
BSet burner emergency switch (Æfig. 13, [2]) to AUT.
BDepending on controller type, release the lever or button (Æfig. 14,
page 14).
BPush on the button of the temperature controller (Æfig. 13, [1]).
BSet controllers, switches and thermostats to the equipment-specific
conditions.
BSet the temperature controller to AUT.
Fig. 13 Checking the STB using the burner emergency operation switch
[1] Thermostat selector button
[2] Burner emergency operation switch
CAUTION: System damage due to incorrect installation
of the STB at the boiler!
The sensor must be pushed into the sensor well as far as
possible to ensure a reliable and fast shutdown in caseof
excesstemperature.
BEnsure an optimum heat transfer from STB sensor to
boiler.
BThe sensor must be secured in the sensor well by
means of the sensor locks (standard delivery).
BEnsure that capillaries are not damaged or kinked.
BVerify the function of the STB before commissioning.
BRegular checks must be performed in accordance
with the boiler manufacturer's specifications.
DANGER: Risk to life through boiler excesstemperature!
Never perform the STB test without supervision.
BImmediately interrupt the test if the set STB
temperature is exceeded.
BRelease the lever or button (depending on controller
type) of the temperature controller.
BSet burner emergency switch to AUT.
6 720 803 704-10.1T
12

14 | Commissioning
CFB 8406 720 802 836 (2012/05)
Fig. 14 Triggering the high limit safety cut-out
[1] Key
[2] Lever
6.2.3 Resetting the high limit safety cut-out
Fig. 15 Resetting the high limit safety cut-out
BUndo the cap.
BPush the reset button underneath.
BRefit the cap.
6 720 803 704-09.1T
1
2

Settings | 15
6 720 802 836 (2012/05)CFB 840
7 Settings
7.1 Adjustable parameters and display data
Some options are only displayed subject to the installed modules and
prior settings.
Fig. 16 Adjustable parameters and display data
General parameters External Day/Night/Aut
Minimum outside temperature External fault message - pump
Type of building Screed drying
Summer/winter time adjustment Screed temperature rise
Remote adjust. Screed heat-up time
Heat yield Maximum screed temperature xxxx
Level limit transducer Maximum screed time
Fault message manual control Screed setback temperature
Automatic maint. message Screed setback time
Module selection Heating circuit 0, 2, 3, 4 see heating circuit 1
Slot A DHW
Slot 1 DHW yes/no
Slot 2 DHW range to
Boiler param. Switching optimisation
Boiler type Residual heat use
Fuel Hysteresis
Ecostream control Boiler raising
Type of burner External fault message WF1/WF2
Sequence reversal after ... Hours External contact WF1/WF3
Minimum modulation output Thermal disinfection
Burner set motor runtime Thermal disinfection temperature
Load limit from outside temperature Thermal disinfection weekday
Boiler pump function Thermal disinfection time
Boiler pump run-on time Daily heat-up
Minimum burner runtime DHW circulation (start frequency per hour)
Pump logic temperature Special parameters
Minimum start temperature Heating characteristics
Maximum shutdown temperature Heating curve heating circ. 0
Flue gas temperature limit Heating curve heating circ. 1
Heating curve heating circ. 2Heating circ. 1
Heating system Heating curve heating circ. 3
Heat. circ. desig. Heating curve heating circ. 4
Low end temp. Relay test
Design temperature Boiler
Minimum flow temperature Heating circ. 0
Maximum flow temperature Heating circ. 1
Remote control Heating circ. 2
Maximum room infl Heating circ. 3
Setback type Heating circ. 4
Outside hold frm. DHW
Holiday setback type LCD test
No setback below ... Fault
Flow setback Monitor
Room temperature offset Boiler
Automatic adaptation Heating circ. 0
Switching optimisation Heating circ. 1
Stop optimisation Heating circ. 2
Frost prot from Heating circ. 3
DHW priority Heating circ. 4
Servomotor (not on heating circuit 0) DHW
Servomotor runtime Version
Boiler raising Control unit
Reset
Control unit settings
Burner Hours run
Fault log
Maximum flue gas temperature
Heat yield
Maint. message
6 720 802 836-08.1TL

16 | General specification data
CFB 8406 720 802 836 (2012/05)
7.2 Calling up the service level
BPress buttons Display, Heating circuit and Temp simultaneously and
release.
Fig. 17 Calling up the service level
[1] Temperature key
[2] Display key
[3] Heating circuit key
The service level is enabled and the display shows:
Fig. 18 Service level
7.2.1 Control system "Press and turn"
The control unit is controlled by pushing the buttons orturning the rotary
dial.
The Service level is split over several main menu levels. If the last line is
left blank (without value entry), there are further submenus connected
to the main menu selected.
7.2.2 Calling up main menus
The rotary dial is used to scroll through the main menu. The main menus
are structured as a loop and recommence after the last main menu.
•GENERAL PARAM.
•Module selection
•...
•GENERAL PARAM.
7.2.3 Calling up submenus
BTurn the rotary dial until the main menu containing the submenu is
highlighted.
BPress button Display.
The submenu is shown.
BTurn the rotary dial to access all submenus of the main menu.
7.3 Calling up and modifying settings
BCalling up the service level (Æchapter 7.2, page 16).
GENERAL PARAM. appears as the first main menu.
BPress Display to call up a submenu.
The display shows the selected submenu.
BPress and hold Display.
BTurn the rotary dial to the required value.
The display shows the set value.
BRelease Display to save your input.
BPress Back to return to the next higher level.
To return to the standard display:
BPress Back several times.
8 General specification data
BCall up the service level.
GENERAL PARAM. appears as the first main menu.
BPress Display to call up a submenu.
BTurn the rotary dial until the required submenu is shown.
Turn the rotary dial to scroll through the following submenus:
•Minimum outside temperature
•Type of building
•Summer/wintertime changeover
•Remote adjust.
•Amount of heat
•Manual fault message control
•Automatic maint. message
BPress button Display to call up a submenu.
The display shows the selected submenu, and settings can be made.
Access to the Service level is password protected. The
Service level is only intended for heating contractors.
Unauthorised access to the service level invalidates your
warranty.
AUT
2
3
1
6 720 803 703-18.1T
SERVICE LEVEL
Gen. Parameters
6 720 802 836-19.1TL
The menus displayed on the programming unit of the
control unit depend on which modules are fitted and on
their settings.
The control unit automatically reverts to the standard
display if no key is pressed for some time or if the flap is
shut.
In main menu GENERAL PARAM. values can be adjusted
for the submenus listed above and the building
characteristics. The following pages explain how to
adjust values relating to the submenus.

General specification data | 17
6 720 802 836 (2012/05)CFB 840
8.1 Minimum outside temperature
The minimum outdoor temperature is an average value of the lowest
outdoor temperatures of the past years and defines together with the
design temperature the end point of the heating curve.
Fig. 19 Heating curve adjustment: Adjustment of gradient via design
temperature and minimum outside temperature
[TminA] Minimum outside temperature
[TA] Design temperature (flow temperature that should be achieved
at min. outside temperature)
[1] Adjustment: Design temperature 75 °C, minimum outside
temperature –10 °C (standard curve)
[2] Adjustment: Design temperature 75 °C, minimum outside
temperature –20 °C
BCall up the service level.
GENERAL PARAM. appears as the first main menu.
BPress Display to call up a submenu.
BTurn the rotary dial until submenu Min outdoor temp is displayed.
Fig. 20 Minimum outside temperature
BHold down button Display and turn the rotary dial until the required
value is shown.
The display shows the set value.
BRelease Display to save your input.
BPress Back to return to the next higher level.
The minimum outside temperature for your region
(average value) is stated in tab. 12. If your particular
region is not shown in the table, set an average value
between the two cities closest to you or take the value
from the heat demand calculation for your building.
[°C]
[°C]
1 2
6 720 803 703-21.1T
TminA
T
A
GENERAL PARAM.
Min outdoor temp
-10 C
o
6 720 802 836-20.1TL
Input range Factory setting
Min outdoor temp -30 °C – 0 °C -10 °C
Table 11 Setting range Minimum outside temperature
Town Minimum outside temperature in °C
Athens –2
Berlin –15
Brussels –10
Budapest –12
Bucharest –20
Frankfurt/M –14
Hamburg –12
Helsinki –24
Istanbul –4
Copenhagen –13
Lisbon 0
London –1
Madrid –4
Marseilles –6
Moscow –30
Munich –16
Naples –2
Nice 0
Paris –10
Prague –16
Rome –1
Sevastopol –12
Stockholm –19
Valencia –1
Vienna –15
Zurich –16
Table 12 Minimum outside temperature in Europe

18 | General specification data
CFB 8406 720 802 836 (2012/05)
8.2 Type of building
In submenu Type of building the heat storage capacity of the building is
entered. Different types of construction have different heat storage
capacities. This function sets the heating system to the specified
construction type.
The heat storage capacity is divided into three categories.
BCall up the service level.
GENERAL PARAM. appears as the first main menu.
BPress Display to call up a submenu.
BTurn the rotary dial until submenu Type of building is displayed.
BHold down button Display and turn the rotary dial until the required
value is shown.
The display shows the set value.
BRelease Display to save your input.
BPress Back to return to the next higher level.
8.3 Summer/wintertime changeover
Three different date and time setting options are available for all
connected control units:
When using the Programmer as remote control, the reception of the
radio clock signal depends on each location and position. Reception of
the radio clock signal is indicated by a symbol on the display (Æfig. 7,
[1], page 8). Normally, reception is possible within a radius of approx.
1000 miles around Frankfurt/Main [Germany].
In case of reception problems, please observe the following:
•The radio reception is weaker in rooms surrounded by steel-
reinforced walls, cellars, high-rise buildings etc.
•Maintain a minimum distance of 1.5 m from sources of interference,
such as computer monitors and TV sets.
•The radio reception tends to be better at night than during the day.
BCall up the service level.
GENERAL PARAM. appears as the first main menu.
BPress Display to call up a submenu.
BTurn the rotary dial until submenu Summer / Winter
Time changeover is displayed.
BHold down button Display and turn the rotary dial until the required
value is shown.
The display shows the set value.
Fig. 21 Summer/winter time changeover
BRelease Display to save your input.
BPress Back to return to the next higher level.
Class Explanation
light heat storage capacity
e.g. prefabricated building, wood-frame
construction
medium medium heat storage capability,
e.g. house built with breeze blocks
heavy heat storage capacity
e.g. brick house
Table 13 Heat storage capacity
Input range Factory setting
Type of building medium
heavy
light
medium
Table 14 Setting range Building type
Setting
options Explanation
Radio clock The adjustment is made completely automatically by
the radio time signal.
Automatic Date and time input with keypad. The change from
summer to winter time and vice versa is made
automatically on the last weekend in March and
October.
Manual Single date and time input via keypad. There will be no
automatic summer/wintertime adjustment.
Table 15 Setting options Date and time
The Programmer contains a radio receiver, which
constantly monitors and corrects the time switch inside
the control unit. You never need to set the time during
commissioning, after prolonged power failure, after the
heating system has been switched off for longer periods
on its mains electrical isolator or for changing from
summer to winter time and vice versa.
Well screened boiler rooms in cellars can restrict the
reception of the radio clock signal, which makes it
necessary for you to set the date and time manually.
Do not enable the "Radio clock" function outside
Germany.
If not Radio clock is selected, the reception of the
atomic clock signal will be turned off for all networked
control units. This also applies to the radio time signals of
the BFU/F remote control and other programming units
with radio clock reception. The last input at a control unit
in the network is valid.
Input range Factory setting
Summer/winter
Time changeover
Radio clock
automatic
manual
Automatic
Table 16 Setting range Summer/winter time changeover
GENERAL PARAM.
Summer / Winter
Time changeover
Radio clock
6 720 802 836-22.1TL

General specification data | 19
6 720 802 836 (2012/05)CFB 840
8.4 Remote adjust
The remote adjustment offers the option of external data entry and
adjustment via a remote system.
BCall up the service level.
GENERAL PARAM. appears as the first main menu.
BPress Display to call up a submenu.
BTurn the rotary dial until submenu Remote adjust. is displayed.
BHold down button Display and turn the rotary dial until the required
value is shown.
The display shows the set value.
BRelease Display to save your input.
BPress Back to return to the next higher level.
8.5 Manual fault message control
A fault message can be shown in the display of the programming unit
when the manual switch of the function module is set to Manual.
BCall up the service level.
GENERAL PARAM. appears as the first main menu.
BPress Display to call up a submenu.
BTurn the rotary dial until submenu Fault message manual control is
displayed.
BHold down button Display and turn the rotary dial until the required
value is shown.
The display shows the set value.
Fig. 22 Manual fault message control
BRelease Display to save your input.
BPress Back to return to the next higher level.
8.6 Automatic maint. message
At the user level an automatic maintenance message to appear on the
programming unit display can be generated.
The following settings are possible:
•Maintenance message by date. Entry of the date of the next service
date (01.01.2000 – 31.12.2088).
•Maintenance after hours run (only for control units with direct boiler
control).
BCall up the service level.
GENERAL PARAM. appears as the first main menu.
BPress Display to call up a submenu.
BTurn the rotary dial until submenu automatic maint. message is
displayed.
BHold down button Display and turn the rotary dial until the required
value is shown.
The display shows the set value.
Fig. 23 Automatic maint. message
BRelease Display to save your input.
BTurn the rotary dial one increment clockwise.
Setting
options Explanation
yes Optional remote adjustment via the telecontrol system
no Remote adjustment is not possible, but system data
can be downloaded and monitored.
Table 17 Setting options Remote adjustment
This parameter cannot be adjusted via the telecontrol
system; it is only intended to be changed in situ.
Input range Factory setting
Remote adjust. yes
no
yes
Table 18 Setting range Remote adjustment
GENERAL PARAM.
Fault message
manual control
Fault message
6 720 802 836-23.1TL
If No is shown, a warning notice appears if the flap is
closed.
If Fault message is shown, an entry also appears in the
fault log. Automatic forwarding via the CFB 840
telecontrol system is then possible.
If cent. fault mess is shown, the output of a central fault
message also appears via a volt free contact e.g. via the
FM448/CMB 900-0-10V function module.
Input range Factory setting
Fault message
manual control
No
Fault message
central fault message
no
Table 19 Setting range Manual switch fault message
The maintenance message "after hours run" is not
possible with this control unit.
GENERAL PARAM.
automatic
maint. message
Date
6 720 802 836-24.1TL

20 | Boiler parameters
CFB 8406 720 802 836 (2012/05)
BHold down button Display and turn the rotary dial until the required
value is shown.
The display shows the set value.
Fig. 24 Setting the automatic service date
BRelease Display to save your input.
BPress Back to return to the next higher level.
The status of the maintenance message can be scanned in menu
Monitor. The maintenance message can be reset in menu Reset.
8.7 Module selection
On starting the control units or after a system reset, the modules are
automatically recognised and their information downloaded.
Example:
•Slot 1: ZM424
•Slot 2: free
However, these modules can also be set manually if required.
BCall up the service level.
GENERAL PARAM. appears as the first main menu.
BTurn the rotary dial until main menu Module selection appears.
BPress Display to call up a submenu.
BTurn the rotary dial until submenu Pos. 1 is displayed.
BHold down button Display and turn the rotary dial until the required
value is shown.
The display shows the set value.
Fig. 25 Module selection
BRelease Display to save your input.
BPress Back to return to the next higher level.
9 Boiler parameters
9.1 Select boiler type
Subject to the selected boiler type, special setting options will be
displayed. For further information regarding the setting of boiler-
specific parameters, see Æchapter 23.2, page 50.
BCall up the service level.
GENERAL PARAM. appears as the first main menu.
BTurn the rotary dial until main menu Boiler param. appears.
BPress Display to call up a submenu.
Boiler type appears as the first main menu. Thedisplay shows the set
value.
BHold down button Display and turn the rotary dial until the required
value is shown.
BRelease Display to save your input.
BPress Back to return to the next higher level.
9.1.1 Low temperature boilers
The low temperature boiler is operated with a factory-set pump logic,
which depends on the selected burner type.
Setting the pump logic temperature
The heating circuit circulation pumps and, if installed, the boiler circuit
pump are switched on and off to maintain theboiler operating conditions
subject to the pump logic temperature. The preset pump logic
temperature only needs to be changed in special cases and is only
adjustable in case of boiler type = low temperature.
The factory-set pump logic temperature is 5 K below the minimum
shutdown temperature of the boiler.
BCall up the service level.
GENERAL PARAM. appears as the first main menu.
BTurn the rotary dial until main menu Boiler param. appears.
BPress Display to call up a submenu.
BTurn the rotary dial until submenu Pump logic temperature appears.
BHold down button Display and turn the rotary dial until the required
value is shown.
BRelease Display to save your input.
BPress Back to return to the next higher level.
The maintenance message is recorded in the fault log
and can be transferred via the CFB 840 telecontrol
system.
Input range Factory setting
automatic
maint. message
No
Operating hours
Date
no
Table 20 Setting range Automatic maintenance message
Recommended setting: Function module none/auto.
The modules are automatically recognised and installed.
GENERAL PARAM.
maint. message
on
01.10.2012
6 720 802 836-25.1TL
Input range Factory setting
Boiler type Low temperature
Ecostream
Condensing
LT/Base line
temperature
Low temperature
Table 21 Setting range Boiler type
MODULE SELECTION
Pos. 1
Function module
none/auto
6 720 802 836-29.1TL