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; Faults Not Indicated At The Module - Bosch EMS-2 Notice D'installation

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 48
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 Buffer cylinder is at
yellow least 10 K below the
set temperature
Constantly green Buffer cylinder is no
more than 5 K below
the set temperature
Table 49
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 50
5.6

Faults not indicated at the module

Error 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 51
ME 200 – 6720884576 (2019/08)
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.
6

Overview of the service menu

The menus depend on which control unit and system is installed. The
menu items are displayed in the sequence listed below.
Service menu
Commissioning
– ...
– Altern. HS (alternative heat source)
– ...
– ...
Set altern. HS (Setting of alternative heat source)
– Alt. heat source activation (Activation of alternative heat source)
– Relay output config. (Relay output configuration)
– Buffer primary pump
– Config. pump (pump configuration)
– Output for pump
– Min. output of pump
– Start conf. pump (pump start configuration)
– Mixer return AHS (Mixer return, alternative heat source)
– AHS return temp rise (Return temperature increase, alternative
heat source)
– Mixer run time
– Set temp. return (Set temperature, return temperature increase)
– Buffer (Buffer cylinder)
– Set flow temp. AHS (Flow temperature for charging the buffer
cylinder)
– Buffer bypass
– Bypass mixer run time
– DHW via buffer
– Config. DHW cylinder (Configuration, DHW cylinder)
– Blocking mode
– Config. htg. blocking mode (Configuration, heating blocking
mode)
– Conf. DHW blocking mode (Configuration, DHW blocking mode)
– Hyst. for boiler block (Switching differential for boiler block)
– Boiler release wait.time (Waiting time until boiler release)
– Blocking output selection
– Config. of block.terminal (Configuration, blocking terminal)
Diagnosis
– Function test
– Altern. HS (alternative heat source)
– ...
– ...
– Monitored values
– Altern. HS (alternative heat source)
– ...
– ...
Overview of the service menu
33