*****INTERNAL*****30 R_D proof- 26.10.2022 / 09:15:46- VaillantGroup\DOC-agt\Brand\VIH_QW_190_6\ENG\OI-II_GB_0020291525
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Installation and maintenance instructions 0020291525_04
Code
Meaning
S.111 Cooling: Compressor
shutdown
The cooling demand is met, the demand is ended by the system control. The compressor is switched
off.
S.112 Cooling: Compressor
blocked
The compressor is blocked for cooling mode because the heat pump is outside of its application lim-
its.
S.113 Cooling: Compressor
mode prerun
The start conditions for the compressor in cooling mode are checked. Start the other actuators for
cooling mode.
S.114 Cooling: Compressor
active
The compressor works in order to meet the cooling demand.
S.117 Cooling: Compressor
mode overrun
The cooling demand is met, the compressor is switched off. The pump and fan overrun.
S.125 Heating: Immersion
heater active
The immersion heater is used in heating mode.
S.132 Domestic hot water:
Compressor blocked
The compressor is blocked for domestic hot water mode because the heat pump is outside of the
application limits.
S.133 Domestic hot water:
Prerun
The start conditions for the compressor in domestic hot water mode are checked. Start the other actu-
ators for domestic hot water mode.
S.134 Domestic hot water:
Compressor active
The compressor works in order to meet the domestic hot water demand.
S.135 Domestic hot water:
Immersion heater active
The immersion heater is used in domestic hot water mode.
S.137 Domestic hot water:
Overrun
The domestic hot water demand is met, the compressor is switched off. The pump and fan overrun.
S.141 Heating: Immersion
heater shutdown
The heat demand is met, the immersion heater is switched off.
S.142 Heating: Immersion
heater blocked
The immersion heater is blocked for heating mode.
S.151 Domestic hot water:
Immersion heater shutdown
The domestic hot water demand is met, the immersion heater is switched off.
S.152 Domestic hot water:
Immersion heater blocked
The immersion heater is blocked for domestic hot water mode.
S.173 Anti-cycling time for
the energy supply company
The mains voltage supply is interrupted by the energy supply company. The maximum anti-cycling
time is set in the configuration.
S.202 Check programme: Pur-
ging of building circuit active
The building circuit pump is actuated in cyclical intervals, alternately in heating mode and domestic
hot water mode.
S.203 Actuator test active
The sensor and actuator test is currently operating.
S.212 Connection fault: Con-
trol not recognised
System control was previously detected but the connection is broken. Check the eBUS connection to
the system control. It can only be operated with the heat pump's additional functions.
S.240 Compr. oil temp. too
low, environment too cold
The compressor heating is switched on. The unit does not start up.
S.252 Fan unit 1: Fan blocked
If the fan speed is 0 rpm, the heat pump is switched off for 15 minutes and then restarted. If the fan
does not start up after four unsuccessful restarts, the heat pump is switched off and the fault mes-
sage
F.718
is displayed.
S.255 Fan unit 1: Air inlet
temp. too high
The compressor does not start because the outdoor temperature at the fan is above the application
limits. Heating mode: > 43 °C. Domestic hot water mode: > 43 °C. Cooling mode: > 46 °C.
S.256 Fan unit 1: Air inlet
temp. too low
The compressor does not start because the outdoor temperature at the fan is below the application
limits. Heating mode: < -20 °C. Domestic hot water mode: < -20 °C. Cooling mode: < 15 °C.
S.260 Fan unit 2: Fan blocked
If the fan speed is 0 rpm, the heat pump is switched off for 15 minutes and then restarted. If the fan
does not start up after four unsuccessful restarts, the heat pump is switched off and the fault mes-
sage
F.785
is displayed.
S.272 Building circuit: Re-
maining feed head limit active
The remaining feed head that is set under the configuration is reached.
S.273 Building circuit: Flow
temperature too low
The flow temperature that is measured in the building circuit is below the application limits.
S.275 Building circuit: Flow
rate too low
Building circuit pump defective. All consumers in the heating system are closed. The values fall below
the specific minimum volume flows. Check that the dirt filter is permeable. Check the stopcocks and
thermostatic valves. Ensure that the flow rate is at least 35% of the nominal flow rate. Check that the
building circuit pump functions correctly.
S.276 Building circuit: Lock-
out contact S20 open
Contact S20 is open at the heat pump's main PCB. Incorrect limit thermostat setting. Flow temper-
ature sensor (heat pump, gas-fired boiler, system sensor) measures values that deviate downwards.
Adjust the maximum flow temperature for the direct heating circuit via the system control (observe
the upper switch-off threshold for the boilers). Adjust the set value for the limit thermostat. Check the
sensor values
