B Status Codes - Overview - Vaillant ecoTEC plus VU 446/5-5 (H-GB) Installation And Maintenance Instructions Manual

Code Parameter
D.148 Target value for the available pres-
sure in the cylinder charging circuit
D.149 Precise information about circulation
fault F.75
Status codes – Overview
B
Status code Meaning
Heating mode
S.0 Heating demand
S.1 Heating mode: Fan start-up
S.2 Heating mode: Pump start-up
S.3 Heating mode: Ignition
S.4 Heating mode: Burner on
S.5 Heating mode: Pump/fan overrun
S.6 Heating mode: Fan reduction
S.7 Heating mode: Pump overrun
S.8 Heating mode, burner anti-cycling time
Cylinder charging mode
S.20 Domestic hot water requirement
S.21 DHW mode: Fan start-up
S.22 Domestic hot water mode: Pump running
S.23 DHW mode: 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 burner anti-cycling time
Special cases
S.30 Room thermostat (RT) is blocking heating mode
S.31 Summer mode active or no heat requirement from eBUS control
S.32 Waiting period: Deviation in fan speed
S.33 Air pressure switch calibration
S.34 Frost protection mode active
S.36 Reference setting for the continuous control 7-8-9 or eBUS control is < 20 °C and blocks the heating mode
S.39 Limit thermostat for the underfloor heating triggered
S.41 Water pressure too high
S.42 Return signal for the flue non-return flap (only if an accessory) blocks burner operation or condensate pump faulty, heat
demand blocked
S.53 Modulation blocked by operating block function due to water deficiency (flow and return spread too great)
S.54 Product in standby caused by operating blocking function as a result of water deficiency (temperature gradient)
S.85 Service message "Insufficient water flow rate, product in standby mode for 10 minutes"
0020261389_02 ecoTEC plus Installation and maintenance instructions
Values or explanations
100 ... 400 mbar
If fault F.75 occurs, read the explanation below for
the relevant value of the diagnostics code in order to
analyse the problem.
0 = No fault
1 = Pump blocked
2 = Electrical pump fault
3 = Pump dry run
5 = Pressure sensor fault
6 = No feedback from the pump
7 = Incorrect pump detected
8 = Flow rate at the end of the purge programme is
insufficient
Appendix
Default User-spe-
setting cific setting
200 mbar
45