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Installation instructions geoTHERM VWS/VWW 0020051574_01
Fault code Error text/description
Emergency
mode
Possible cause
Solution
60
Frost protection heat source
monitoring source outlet
Error 20 has occurred three
times in a row
possible
See Error 20.
See Error 20.
61
only VWW
Frost protection heat source
monitoring source outlet
Error 21 has occurred three
times in a row
possible
See Error 21.
See Error 21.
62
only VWS
Frost protection heat source
monitoring source outlet
Error 22 has occurred three
times in a row
possible
See Error 22.
See Error 22.
63
only VWW
No ground water flow
Error 23 has occurred three
times in a row
possible
See Error 23.
See Error 23.
72
Flow temperature too high
for underfloor heating
Flow temperature is higher
than a preset value for
15 min (max. HK temp. +
compr.hyst 2 K) (see
Chap. 8.10, default setting:
52 °C).
_
Flow sensor VF2 fitted too close to
the heat pump.
Relocate flow sensor in accordance with
hydraulic plan.
Flow sensor VF2 is defective
Check flow sensor VF2, replace if neces-
sary.
Defective heating circulation pump
or pump output has reduced.
Test heating circulation pump, replace if
necessary.
Existing dirt strainers clogged or in-
correctly dimensioned.
Clean dirt strainers.
Mixer behind buffer cylinder is defec-
tive.
Test mixer, replace if necessary.
Max. HK temp. set too low.
Check "Max. HK temp." setting.
81
Coolant pressure too high
Error 27 has occurred three
times in a row
possible
See Error 27.
See Error 27.
83
Coolant pressure too low.
Check heat source
Error 28 has occurred three
times in a row
possible
See Error 28.
See Error 28.
84
Coolant pressure outside
the range
Error 29 has occurred three
times in a row
possible
See Error 29.
See Error 29.
90
Heating system pressure
too low
Pressure <0.5 bar
Heat pump shuts down and
goes into operation auto-
matically when the pressure
rises above 0.7 bar
_
Pressure drop in the heating system
as a result of leakage, air lock or de-
fective expansion vessel.
Check heating system for leaks, top up
water, bleed, check the expansion vessel.
Screw couplings at the rear of the
heat pump are not sealing correctly.
Retighten screw couplings.
Compression fittings on 3-way valve
are leaking.
Retighten compression fittings on 3-way
valve.
Table 10.5 Fault-induced shutdown (cont.)
Troubleshooting and diagnosis 10