Vaillant geotherm exclusive Installation Instructions Manual page 77

Fault
Error text/description
code
60 Frost protection heat source
monitoring source outlet
Error 20 has occurred three
times in a row
62 Frost protection heat source
monitoring source outlet
Error 22 has occurred three
times in a row
72 Flow temperature too high
for underfloor heating
Flow temperature is higher
than a preset value for
15 min (max. HK temp. +
compr.hysteresis + 2 K)
(see Chap. 8.10, default set-
ting: 52 °C) .
81 Coolant pressure too high
Error 27 has occurred three
times in a row
83 Coolant pressure too low.
Check heat source
Error 28 has occurred three
times in a row
84 Coolant pressure outside
the range
Error 29 has occurred three
times in a row
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
Table 10.4 Fault-induced shutdown (ctnd.)
geoTHERM exclusive VWS 0020051614_00 installation instructions
Emergency
Possible cause
mode
possible
See Error 20.
possible
See Error 22.
_ Flow sensor VF2 fitted too close to the
heat pump.
Flow sensor VF2 is defective
Defective heating circulation pump or
pump output has reduced.
Existing dirt strainers clogged or incor-
rectly dimensioned.
Mixer behind buffer cylinder is defec-
tive.
Max. HK temp. set too low.
possible
See Error 27.
possible
See Error 28.
possible
See Error 29.
_ Pressure drop in the heating system as
a result of leakage, air lock or defec-
tive expansion vessel.
Screw couplings at the rear of the heat
pump are not sealing correctly .
Compression fittings on 3-way valve
are leaking.
Troubleshooting and diagnosis 10
Solution
See Error 20.
See Error 22.
Relocate flow sensor in accordance with
hydraulic plan.
Check flow sensor VF2, replace if neces-
sary.
Test heating circulation pump, replace if
necessary.
Clean dirt strainers.
Test mixer, replace if necessary.
Check "Max. HK temp." setting.
See Error 27.
See Error 28.
See Error 29.
Check heating system for leaks, top up
water, bleed, check the expansion vessel.
Retighten screw couplings.
Retighten compression fittings on 3-way
valve.
77