Fault With Temporary Lock-Out; Fault With Permanent Lock-Out - Vaillant geoTHERM VWS 220/2 Instrucciones De Operación

5.4

Fault with temporary lock-out

The heat pump is shut down temporarily and starts up
again automatically when the cause of the fault no longer
exists or has been eliminated.
Depending on the fault, the heat pump switches back on
automatically after 5 or 60 minutes.
Fault code Fault text/description
20 Heat source frost protect source outlet monitoring
The difference between the outlet temperature
and inlet temperature of the heat source is too
low.
The transfer of thermal energy by the heat source
is temporarily insufficient for heat pump opera-
tion. The controller shuts down the heat pump
temporarily in order to prevent it from freezing.
The heat pump cannot be restarted until after 5
min. at the earliest.
21 Heat source frost protect source outlet monitoring
(VWW only)
Source outlet temperature T8
too low (<4 °C)
22 Heat source frost protect source outlet monitoring
(VWS only)
The heat source outlet temperature is too low.
The transfer of thermal energy by the heat source
is temporarily insufficient for heat pump opera-
tion. The controller shuts down the heat pump
temporarily in order to prevent it from freezing.
The heat pump cannot be restarted until after 5
min. at the earliest.
23 No ground water flow
(VWW only)
The integrated flow switch does not detect any vol-
ume flow
27 Refrigerant pressure too high
The heat pump can only restart when the refriger-
ant pressure is low. The heat pump cannot be
restarted until after 60 min. at the earliest.
28 Refrigerant pressure too low
The heat pump can only restart when the refriger-
ant pressure is sufficient. The heat pump cannot
be restarted until after 60 min. at the earliest.
29 Refrigerant pressure outside the range
If the fault occurs twice in a row, the heat pump
cannot be started until after 60 min. at the earli-
est.
5.2 Fault with temporary lock-out
Operating instructions geoTHERM 0020051578_03
5.5

Fault with permanent lock-out

Errors may occur which result in the lock-out of the heat
pump.
i
Only a heating engineer can eliminate the cause
of the faults described below and delete the
error history.
The basic display disappears and the fault message
is shown on the display.
Emergency mode
Depending on the type of malfunction, the heating engineer
can set the heat pump to continue running in emergency
mode via an external electric auxiliary heater or an external
boiler until the cause of the fault has been eliminated. If
emergency mode is possible (¬ table 5.3), i.e. an external
electric auxiliary heater or an external boiler has been ena-
bled for this purpose, the heating engineer can enable
these either for heating mode or hot water handling, or for
both.
The following parameters appear beneath the fault
message:
– Reset (YES/NO)
Deletes the fault message and enables compressor oper-
ation.
– DHW priority (YES/NO)
Enables the auxiliary heater for hot water handling.
– CH priority (YES/NO)
Enables the auxiliary heater for heating mode.
Troubleshooting
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