Appendix
0020230529_04 ecoFIT sustain Installation and maintenance instructions
33
Status code
Meaning
S.16
DHW mode: Fan overrun
S.17
DHW mode: Pump overrun
Display in comfort mode with warm start or domestic hot water mode with cylinder
S.20
Domestic hot water mode: Requirement
S.21
Domestic hot water mode: Fan prerun
S.22
Domestic hot water mode: Pump prerun
S.23
Domestic hot water mode: Burner ignition
S.24
DHW mode: Burner on
S.25
DHW mode: Pump/fan overrun
S.26
DHW mode: Fan overrun
S.27
DHW mode: Pump overrun
S.28
Domestic hot water mode: Temporary shutdown of the burner
Other displays
S.30
Room thermostat is blocking heating mode.
S.31
No heating demand: Summer mode, eBUS control, waiting period
S.32
Fan waiting time: Fan speed outside of the tolerance values
S.33
Forced fan operation until the pressure monitor is switched
S.34
Frost protection active
S.39
Underfloor heating contact open
S.41
Water pressure too high
S.42
Flue non-return flap closed
S.46
Frost protection mode (Comfort): Minimum load
S.53
Product in waiting period/operating block function due to water deficiency (flow/return spread too large)
S.54
Waiting period: Water deficiency in the circuit (flow/return spread too large)
S.76
Maintenance message: Check the water pressure
S.88
Product purging active
S.91
Maintenance: Demo mode
S.96
Automatic test programme: Return temperature sensor, heating demands blocked.
S.97
Automatic test programme: Water pressure sensor, heating demands blocked.
S.98
Automatic test programme: Return temperature sensor, heating demands blocked.
S.99
Internal automatic test programmes
S.108
Purging the combustion chamber, fan in operation
S.109
Product's standby mode activated
C
Overview of fault codes
Note
Since the code table is used for various products, some codes may not be visible for the product in question.
Fault code
Meaning
Possible cause
F.00
Fault: Flow temperature sensor
NTC plug not plugged in or has come loose, multiple plug on the PCB not
plugged in correctly, interruption in cable harness, NTC sensor defective
F.01
Fault: Return temperature sensor
NTC plug not plugged in or has come loose, multiple plug on the PCB not
plugged in correctly, interruption in cable harness, NTC sensor defective
F.10
Short circuit: Flow temperature sensor
NTC sensor defective, short circuit in the cable harness, cable/housing
F.11
Short circuit: Return temperature sensor
NTC sensor defective, short circuit in the cable harness, cable/housing
F.12
and
F.91
Short circuit: Cylinder temperature
sensor
NTC sensor defective, short circuit in the cable harness, cable/housing
F.13
Short circuit: Domestic hot water cylinder
temperature sensor
NTC sensor defective, short circuit in the cable harness, cable/housing
