Bosch CFB 840 Servicing Instructions
Control Unit
CFB 840
6 720 803 855-00.1T
Servicing instructions for heating contractors
6 720 802 836 (2012/05) GB/IE/AU
2 | Table of contents
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
CFB 8406 720 802 836 (2012/05)
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
Table of contents | 3
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
6 720 802 836 (2012/05)CFB 840
4 | Key to symbols and safety instructions
1 Key to symbols and safety instructions
1.1 Key to symbols
Warnings
Warnings in this document are framed and identified by
a warning triangle printed against a grey background.
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
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.
Additional symbols
Symbol Meaning
B a step in an action sequence
Æ a reference to a related part in the document or to other
related documents
• a list entry
– a list entry (second level)
Table 1
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.
B Ensure that only a qualified contractor carries out installation,
connection of exhaust system, commissioning, maintenance and
service.
B Carry out maintenance at least once a year. As part of this, check that
the entire system is working correctly. Immediately remedy all defec ts
found.
B Read 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.
B Use 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.
B Do not draw off DHW unmixed.
Damage due to operator error
Operator errors can result in injury and damage to property.
B Ensure that children never operate this appliance unsupervised or
play with it.
B Ensure that only personnel who can operate this appliance correctly
have access to it.
B Installation and commissioning as well as servicing and maintenance
must only be carried out by a qualified contractor.
B Before 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
B Ensure that any electrical work is only carried out by an approved
electrician.
B Observe the relevant requirements when working on electrical
installations.
B Ensure 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.
B Before 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.
B Protect 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.
CFB 8406 720 802 836 (2012/05)
Setting instructions | 5
2.3 Notes on commissioning
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.
B Ensure that wiring and other lines are routed at a safe
distance from hot boiler parts.
B Route wiring and other lines, in the wiring ducts
provided or above the boiler insulation.
B Before switching the control unit on, check that its manual switches
and those on the function modules are set to AUT.
B Enter the settings made during commissioning and the allocation of
the heating circuits into the commissioning report in the operating
instructions of the control unit.
B Switch on the control unit first and then the boiler.
B To shut down, switch off the boiler first and then the control unit.
B Ensure that there is sufficient heat load, otherwise the boiler will
switch off and generate a fault condition.
2.4 Cleaning the control unit
B Only clean the control unit with a damp cloth.
2.5 Product description
The digital CFB 840 control unit is suitable for regulating 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 circuit control (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
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
Boiler circuit actuator control V 230
Servomotor runtime, burner
modulating
Type of controller - burner and
heating circuit actuator
Ambient temperatures
• Operation
• Transport
Table 2 Specification - CFB 840 control unit
A
sec 120
°C
8
5
(adjustable from 5 to
60)
Three-point stepper
controller (PI
characteristics)
+5...+50
–20...+55
smallest
lower fault
Sensor
FA –50 –40 50 > 70
FK < –5 0 > 108 > 125
FB < –5 099> 125
Table 3 Sensor measuring range
2.7.2 FM442/CMM 920 function module
Operating voltage (at 50 Hz ± 4%) V 230 ± 10 %
Power consumption VA 2
Maximum switching current - heating
circuit circulation pump output
Heating circuit actuator control V 230
Servomotor runtime sec 120 (adjustable
Type of controller – Three-point stepper
Table 4 Technical data for FM442/CMM 920 function module
Sensor
FV1 flow temp. HC
on left
FB flow temp. HC
on right
Table 5 Sensor measuring range
limit in °C
display value
in °C
lower
fault
limit
in °C
< –5 099125
< –5 099125
smallest
display
value
in °C
highest
display value
in °C
Unit Value
A 5
10 – 600)
controller (PI
characteristics)
highest
display
value
in °C
upper fault limit
in °C
upper fault
limit in °C
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
DANGER: Risk to life from electric shock!
B Before opening the control unit, isolate all poles of the
control unit and secure against unauthorised reconnection.
To be able to set the temperatures, the high limit safety cut-out (STB)
must be removed from the control unit housing.
B Undo screws [1].
B Remove cover [2].
B Remove protective cap [3].
B Undo the screw connection.
B Remove the STB with its assembly plate and make the adjustments
(Æ chapter 3.1.2).
6 720 802 836 (2012/05)CFB 840
6 | Setting instructions
1 1
2
3 2
Fig. 1 Remove the high limit safety cut-out
[1] Screws
[2] Cover
[3] STB protective cap
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.
3.1.2 Adjusting the high limit safety cut-out
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 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.
B Verify the function of the STB before commissioning.
B Regular 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.
B Ensure 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.
Version A
B Undo the screw [3].
B Adjust the temperature scale [2] to setting [1].
B Re-tighten screw [3].
6 720 803 704-03.1T
1
100
110
120
3
6 720 803 704-01.1T
Fig. 2 Adjusting the high limit safety cut-out (STB) - variant A
[1] Marking
[2] Temperature scale
[3] Screw
B Install STB into housing.
B Check the high limit safety cut-out (Æ chapter 6.2, page 13).
Version B
B Set the temperature using a screwdriver.
°C
100
110
120
6 720 803 704-12.1T
Fig. 3 Adjusting the high limit safety cut-out (STB) - variant B
B Install STB into housing.
B Check the high limit safety cut-out (Æ chapter 6.2, page 13).
3.2 Setting instructions for boiler water thermostat (TR)
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 (Æ chapter 9.3.5, page 24).
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.
B Pull off rotary dial.
B Break off the end stop tabs [1].
CFB 8406 720 802 836 (2012/05)
B Reposition rotary dial.
1
Fig. 4 Boiler water temperature controller
[1] End stop tabs
4 Controls and programming unit
4.1 Control unit controls
Controls and programming unit | 7
6 720 803 704-04.1T
1 2 3 4 5 6
Fig. 5 Control unit controls (delivered condition)
[1] High limit safety cut-out
[2] Boiler water temperature controller
[3] Fuse F1
1 2 3 4
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
6 720 803 704-05.1T
[4] Connection for external service equipment and programmer
[5] Burner emergency operation switch
[6] On/Off switch
6 720 803 704-06.1T
[3] Slot B: Programmer (CM431) - programming unit
[4] Slot 2, e.g. FM442/CMM 920 - heating circuit 3, heating circuit 4
6 720 802 836 (2012/05)CFB 840
8 | Controls and programming unit
4.2 Programmer programming unit
17
16
1
15
14
13
12
11
10
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
9 8
2
3
4
5
6
7
6 720 803 703-04.1T
[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
CFB 8406 720 802 836 (2012/05)
Modules and their function | 9
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.
Module CFB 840
Programmer O
CM431 controller module O
Central module ZM422 – burner control,
1 heating circuit + 1 DHW circuit
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
Function module FM445/CML 910 –
LAP/LSP (primary store system)
Function module FM448/CMB 930 –
central fault message
Expansion module ZM426/CME 920 – additional STB X
Function module FM458/CMC 930 – strategy module –
Table 6 Modules and their functions
O
–
X
X
X
Address Description
0 Stand-alone control unit:
Set the address to 0 if the control unit operates as standalone 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 (lead control unit):
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
[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).
B Remove the programming unit.
B You can now set th e control unit address using a screwdriver or similar
tool.
Fig. 8 Address setting
[1] Address setting
1
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6 720 802 836 (2012/05)CFB 840
10 | Modules and their function
5.2 NM482 power supply module
End connection when networking several control units
DANGER: Risk to life from electric shock!
B Ensure that all electrical work is only carried out by a
competent person.
B Before opening the control unit, isolate all poles of the
control unit and secure against unauthorised reconnection.
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]).
1
2
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.
Never use the manual switch to shut down the heating
system during temporary absence. Use the holiday
function for this purpose (Æ operating instructions for
control unit).
The control functions remain operational in manual mode without any
restrictions.
1
12
11
10
9
2
3
6 720 803 703-06.1T
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.
Device
Device
Gerät
4...
4...
Fitting the
Widerstand
end connection
einlegen
Device
Gerät
4...
4...
4...
Device
Gerät
4...
4...
Device
Gerät
4...
4...
Device
Gerät
4...
4...
Fitting the
Widerstand
end connection
einlegen
6 720 803 703-07.1T
Fig. 10 Example of a fitted end connection, in case of several control
units
8
7
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
4
5
6
6 720 803 704-07.1T
CFB 8406 720 802 836 (2012/05)
Modules and their function | 11
5.3.1 Burner function
Flue gas test
B Press and hold button Flue gas test (Æ fig. 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:
B Press button Flue gas test again.
Manual burner switch
In normal operation, the manual switch is set to AUT.
Positions 0, Manual and max I + II of the burner's manual switch are
special settings (Æ fig. 11, [7], page 10) reserved for contractors.
The burner may be directly controlled with the manual switch.
Current functions are indicated by LEDs.
Position Function
AUT
0
max
I+II
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 S and reduced using T.
AUT
AUT
AUT
0
max
I+II
0
max
I+II
0
max
I+II
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
5.3.2 Heating circuit and DHW functions
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
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.
Never use the manual switch to shut down the heating
system during temporary absence. Use the holiday
function for this purpose (Æ see operating instructions
for control units).
The control functions remain operational in manual mode without any
restrictions.
1
2
3
4
5
6
In normal operation, the manual switch is set to AUT.
Positions 0 and Manual are special settings of the manual switch for the
heating circuit and DHW (Æ fig. 11, [6], page 10) reserved to
contractors.
Current functions are indicated by LEDs.
6 720 803 703-13.1T
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
6 720 802 836 (2012/05)CFB 840
12 | Commissioning
Heating circuit function
In normal operation the manual switch should be in the
AUT position.
Positions 0 and Manual are special settings of the manual switch for the
heating circuit (Æ fig. 12, page [6]) reserved to contractors.
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
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.
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.
Depending on the individual application, the display shows various
information:
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.
B Remove 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.
B Press 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:
B Press AUT.
The display shows Data are to ctrl unit sent.
To adopt the data from the control unit:
B Press 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
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:
B Press AUT.
The display shows Data are to ctrl unit sent.
To adopt the data from the control unit:
B Press the Night mode button.
The display shows Data are from ctrl unit taken.
Aut button transmit, Night
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.
CFB 8406 720 802 836 (2012/05)
6.2 Checking the high limit safety cut-out (STB)
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 case of
excesstemperature.
B Ensure an optimum heat transfer from STB sensor to
boiler.
B The sensor must be secured in the sensor well by
means of the sensor locks (standard delivery).
B Ensure that capillaries are not damaged or kinked.
B Verify the function of the STB before commissioning.
B Regular checks must be performed in accordance
with the boiler manufacturer's specifications.
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.
Commissioning | 13
6.2.1 Triggering the high limit safety cut-out
DANGER: Risk to life through boiler excesstemperature!
Never perform the STB test without supervision.
B Immediately interrupt the test if the set STB
temperature is exceeded.
B Release the lever or button (depending on controller
type) of the temperature controller.
B Set burner emergency switch to AUT.
B Set burner emergency switch [2] Manual.
The burner starts.
B Pull off the thermostat selector dial [1].
B Depending on the type of controller, push the lever or button
(Æ fig. 14) back with a screwdriver or similar tool and hold until
the high limit safety cut-out has triggered.
B Continuously monitor the boiler temperature, and interrupt the test,
if required.
6.2.2 Terminating or cancelling the test
B Set burner emergency switch (Æ fig. 13, [2]) to AUT.
B Depending on controller type, release the lever or button (Æ fig. 14,
page 14).
B Push on the button of the temperature controller (Æ fig. 13, [1]).
B Set controllers, switches and thermostats to the equipment-specific
conditions.
B Set the temperature controller to AUT.
1
Fig. 13 Checking the STB using the burner emergency operation switch
[1] Thermostat selector button
[2] Burner emergency operation switch
6 720 803 704-10.1T
2
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14 | Commissioning
1
2
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
B Undo the cap.
B Push the reset button underneath.
B Refit the cap.
6 720 803 704-09.1T
CFB 8406 720 802 836 (2012/05)
7 Settings
7.1 Adjustable parameters and display data
Some options are only displayed subject to the installed modules and
prior settings.
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 pe
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.
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
Heating curve heating circ. 4
Reset
Control unit settings
Burner Hours run
Fault log
Maximum flue gas temperature
Heat yield
Maint. message
Settings | 15
r hour)
Fig. 16 Adjustable parameters and display data
6 720 802 836-08.1TL
6 720 802 836 (2012/05)CFB 840
16 | General specification data
7.2 Calling up the service level
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.
B Press buttons Display, Heating circuit and Temp simultaneously and
release.
AUT
1
3
2
6 720 803 703-18.1T
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:
• GENERAL PARAM.
• Module selection
• ...
• GENERAL PARAM.
7.2.3 Calling up submenus
B Turn the rotary dial until the main menu containing the submenu is
highlighted.
B Press button Display.
The submenu is shown.
B Turn the rotary dial to access all submenus of the main menu.
7.3 Calling up and modifying settings
The menus displayed on the programming unit of the
control unit depend on which modules are fitted and on
their settings.
B Calling up the service level (Æ chapter 7.2, page 16).
GENERAL PARAM. appears as the first main menu.
B Press Display to call up a submenu.
The display shows the selected submenu.
B Press and hold Display.
B Turn the rotary dial to the required value.
The display shows the set value.
B Release Display to save your input.
B Press Back to return to the next higher level.
To return to the standard display:
B Press Back several times.
The control unit automatically reverts to the standard
display if no key is pressed for some time or if the flap is
shut.
8 General specification data
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.
SERVICE LEVEL
Gen. Parameters
6 720 802 836-19.1TL
Fig. 18 Service level
7.2.1 Control system "Press and turn"
The control unit is controlled by pushing the buttons or turning 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.
B Call up the service level.
GENERAL PARAM. appears as the first main menu.
B Press Display to call up a submenu.
B Turn 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
B Press button Display to call up a submenu.
The display shows the selected submenu, and settings can be made.
CFB 8406 720 802 836 (2012/05)
General specification data | 17
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.
1 2
[°C]
A
T
T
minA
Fig. 19 Heating curve adjustment: Adjustment of gradient via design
temperature and minimum outside temperature
] Minimum outside temperature
[T
minA
] Design temperature (flow temperature that should be achieved
[T
A
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
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]
6 720 803 703-21.1T
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
B Call up the service level.
GENERAL PARAM. appears as the first main menu.
B Press Display to call up a submenu.
B Turn the rotary dial until submenu Min outdoor temp is displayed.
GENERAL PARAM.
Min outdoor temp
o
-10
6 720 802 836-20.1TL
Fig. 20 Minimum outside temperature
B Hold down button Display and turn the rotary dial until the required
value is shown.
The display shows the set value.
B Release Display to save your input.
B Press Back to return to the next higher level.
C
6 720 802 836 (2012/05)CFB 840
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