Appendix
0020196687_03 flexoTHERM exclusive Installation and maintenance instructions
49
Code
Meaning
Cause
Remedy
F.714
Environment circuit: Pressure too
low
–
Pressure loss in the environment
circuit due to leakages or air pockets
–
Environment circuit pressure sensor
defective
–
Check the environment circuit for
leaks
–
Top up the medium (brine/water),
purge
–
Check the quality of the plug contact
on the PCB and on the cable har-
ness
–
Check that the pressure sensor is
working correctly
–
Replace the pressure sensor
F.715
Env. circuit: Fault contact: Pump
open
–
The electronics system of the high-
efficiency pump has detected a
fault (e. g. dry running, blockage,
overvoltage, undervoltage) and
switched the pump off as a securing
measure.
–
Switch the heat pump off for at least
30 seconds (no current)
–
Check the quality of the plug contact
on the PCB
–
Check that the pump functions cor-
rectly
–
Purging the environment circuit
F.718
Fan unit 1: Fan blocked
–
There is no confirmation signal stat-
ing that the fan is rotating
–
Check the air route and, if required,
remove any blockages
–
Check and, if required, replace the
F1 fuse on the PCB in the fan unit
(OMU)
F.719
Fan unit 1: Safety cut-out open
–
The safety cut-out on the de-icer is
open due to insufficient volume flow
and/or brine temperatures above
65 °C
–
Operating the de-icer outside of the
permitted area of application
–
De-icer operation when the brine
circuit is not filled
–
During de-icer operation at brine
temperatures above 115 °C, the
safety fuse of the safety cut-out
is tripped and the fuse must be
replaced.
–
Checking for circulation in the envir-
onment circuit pump
–
If required, open the stopcocks. The
safety cut-out is automatically reset
as soon as the temperature at the
fuse falls below 30 °C again. If the
safety cut-out is still open at a de-
icer temperature below 65 °C (or
30 °C), temperatures above 115 °C
were reached and the safety fuse
tripped.
–
Check and, if required, replace the
F1 fuse of the air/brine collector
–
Replace the safety cut-out
F.723
Building circuit: Pressure too low
–
Pressure loss in the building circuit
due to leakages or air pockets
–
Building circuit pressure sensor
defective
–
Check the building circuit for leaks
–
Top up with water, purge
–
Check the quality of the plug contact
on the PCB and on the cable har-
ness
–
Check that the pressure sensor is
working correctly
–
Replace the pressure sensor
F.724
Sensor fault: Fan unit 1 fan inlet
temp.
–
Sensor not connected or sensor
input has short-circuited
–
Check the sensor in the fan unit, and
replace if necessary
–
Replace the cable harness in the fan
unit
F.725
Sensor fault: Fan unit 1 brine flow
temp.
–
Sensor not connected or sensor
input has short-circuited
–
Check the sensor in the fan unit, and
replace if necessary
–
Replace the cable harness in the fan
unit
F.731
High-pressure switch open
–
refrigerant pressure too high. The
integrated high-pressure switch has
tripped at 46 bar (g) or 47 bar (abs)
–
Insufficient energy output via the
relevant capacitors
–
Purging the building circuit
–
Insufficient volume flow as a result of
closing individual room controls in an
underfloor heating system
–
Check that the dirt filter that is in
place is permeable
–
Refrigerant flow rate too low (e.g.
electronic expansion valve defective,
four-way valve mechanically blocked,
filter blocked). Inform Customer
Service.
–
VWL SA (cooling mode): Check the
fan unit for dirt
