Status Indicator "1": Alternative Heat Source; Status Indicator "2": Heat Source Bypass Valve/Pump For Heating Circuit 1 (Stand-Alone); Status Indicator "3": Buffer Cylinder; Status Indicator "4": Conventional Heat Source Block - Bosch ME 200 Installationsanleitung Für Den Fachmann

Troubleshooting
5.2

Status indicator "1": alternative heat source

Status indicator Possible cause
Constantly OFF no heat requirement Normal Operation
Constantly red Temperature sensor
was briefly
connected
incorrectly.
Flow/return
temperature sensor
of alternative heat
heat source defective
Constantly yellow Heat requirement or
flue gas temperature
≥ 100 °C (with stove)
Constantly green No fault
Table 14
5.3 Status indicator "2": heat source bypass valve/pump
for heating circuit 1 (stand-alone)
Status indicator Description
Constantly OFF Stand-alone alternative heat source:
Pump of heating circuit 1 off; no heat requirement and no
heat flow through heating circuit 1
System with conventional heat source:
Bypass valve closed, conventional heat source released and
hydraulically connected.
Constantly green Stand-alone alternative heat source:
Pump of heating circuit 1 on
System with conventional heat source:
Bypass valve open; conventional heat source blocked and
hydraulically bypassed
Table 15
A bypass valve not used is switched in the background. This can be
observed as monitor value in several operating units and cannot be
deactivated.
40
Remedy
▶ Turn the module off and back on.
▶ Check temperature sensor.
▶ If values do not match, replace
the sensor
▶ Check voltage at temperature
sensor terminals in the module.
▶ If the sensor values match but
the voltage values do not,
replace the module
Normal operation or heat-up phase
(transitional phase to normal
operation)
Normal Operation
5.4

Status indicator "3": buffer cylinder

Status indicator Possible cause
Constantly OFF Temperature sensor
not available
Constantly red Temperature sensor
was briefly
connected
incorrectly.
Buffer cylinder
temperature sensor
faulty or heating
system flow/return
temperature sensor
faulty.
Constantly yellow Buffer cylinder is at
least 10 K below the
set temperature
Constantly green Buffer cylinder is no
more than 5 K below
the set temperature
Table 16
5.5

Status indicator "4": conventional heat source block

Status indicator Possible cause
Constantly OFF No conventional heat
source connected
yellow Conventional heat
source blocked
Constantly green Conventional heat
source released
Table 17
5.6

Faults not indicated at the module

Fault Possible cause
Active alternative heat The maximum permissible
source frequently applies temperature of the
internal limit or switches alternative heat source
off completely. has been exceeded.
Table 18
5.7

Faults with fault code

A01 - 1933 - [alternative heat source does not start within 15 minutes.]
Test procedure/Cause
Fault on heat source
Connection to heat source interrupted Check the electrical connection.
Table 19
Remedy
▶ Check connection of
temperature sensor.
▶ Check temperature sensor.
▶ Check connection of
temperature sensor.
▶ Turn the module off and back on.
▶ Check temperature sensor.
▶ If values do not match, replace
the sensor.
▶ Check voltage at temperature
sensor terminals in the module.
▶ If the sensor values match but
the voltage values do not,
replace the module
Normal Operation
Normal Operation
Remedy
If the blocking function is required:
▶ Check whether the heat source
supports the interlock via BUS or
external interlock connection.
▶ Check the corresponding
settings at the control unit.
Normal Operation
Normal Operation
Remedy
▶ Limit set
temperature for
charging of buffer
cylinder.
Action
Check cause of fault and rectify the
fault.
ME 200 – 6721841615 (2021/11)