Bosch CFB 840, Servicing Instructions

Page: 47 / 56

Faults and fault remediation | 47
6 720 802 836 (2012/05) CFB 840
Communicat.
HCx
Because no actual room temperature is
available, the effect of the following
features is disabled: Room influence,
start and stop optimisation, and
automatic adaptation.
•
Remote control incorrectly connected or
defective.
•
Neither a BFU remote control nor a
Programmer was selected for this heating
circuit in the Programmer.
•
Incorrect address allocated to remote
control.
•
Remote control or associated module is
faulty.
B
Check function/connection of remote
control. Also check the address of the
remote control.
B
Select the correct remote control in the
Programmer under Remote control
(
Æ
chapter 10.7, page 26).
B
Check remote control address (see
remote control documentation).
B
Replace remote control or module.
ECO BUS
receive
No effect on control characteristics.
•
The rotary encoder behind the
Programmer in the control unit has an
incorrect address.
•
Gravity switch on NM482 is incorrectly
positioned.
B
Check rotary encoder position
(
Æ
chapter 5.1, page 9).
B
Check gravity switch (
Æ
chapter 5.2,
page 10).
No master System operates with minimum outside
temperature.
•
There is no master control unit (address
1) in the network.
•
Connecting cable to master control unit
broken.
•
Master control unit (address 1) is
switched off or faulty.
B
Check all BUS subscriber addresses.
Address 1 must be allocated to the
master control unit (rotary encoder
behind the Programmer).
B
Check function of connecting cable.
B
Check master control unit and replace if
required.
BUS Addr confl
•
BUS communication no longer
possible.
•
All control functions requiring data
exchange via the ECOCAN BUS can
no longer be implemented.
•
Multiple identical addresses are present.
•
Each address must only be assigned once
in the ECOCAN BUS network.
B
Check the addresses of all BUS
subscribers (address settings,
Æ
chapter 5.1, page 9).
Addr conflict x The functions of the module with the
address conflict can no longer be
carried out. However, communication of
all other modules and control units via
the ECOCAN BUS is still possible.
•
Module is installed in wrong slot.
B
Check wether the module may be
used with this type of control unit
(
Æ
chapter 3.2, page 6).
Incorr module x Module switches all outputs off and
corresponding fault LED on.
•
A different module type is installed in one
slot of the control unit (e.g. FM442/
CMM 920 was replaced by FM441/
CMM 910).
•
The Programmer, the corresponding
module or the control unit is faulty.
B
Insert new module into the programming
unit (
Æ
chapter 8.7, page 20).
B
Check the module selected in the
programming unit (
Æ
chapter 8.7,
page 20).
B
Replace Programmer or module.
Unknown
module x
Module switches all outputs off and
corresponding fault LED on.
•
The controller software is too old to
recognise the module.
•
The module or the control unit is faulty.
B
Check the version of the control unit in
the Programmer (
Æ
chapter 8.7,
page 20).
B
Replace CM431 and MEC if required.
B
Replace module or control unit if
required.
Inert anode No effects on control characteristics.
•
Inert anode incorrectly connected or
faulty.
•
Module is faulty.
B
Check connection.
B
Replace inert anode.
B
Replace module.
ext. fault input
•
An external component is incorrectly
connected or faulty.
•
The module or the control unit is faulty.
B
Check connection.
B
Check connection and function of
external components (cylinder primary
and DHW circulation pumps).
B
Replace module if required.
Manual mode
HCX
Control unit operates in manual mode.
•
It is possible that the manual switch of a
function module has not been set to AUT .
B
Set the corresponding function module
manual control to AUT .
Maint. date No effect on control characteristics.
•
The specified period before the next
service has expired.
B
Perform maintenance and then reset
maintenance message.
Fault Effect on control characteristics Cause Remedy
Table 88 fault overview