0020213394_05 Installation and maintenance instructions
55
Code
Meaning
Cause
Remedy
F.787
Environment circuit: Pressure
mon. open
–
Pressure loss in the environment
circuit due to leakages or air pockets
–
Environment circuit pressure switch
defective
–
Cable not connected either between
X110B and X110 or X110 and
X110A for the power supply PCB.
No 230 V voltage is present at
X131. This is interpreted as an input
contact being open.
–
Bridge at X131 (as supplied). Larger
voltage fluctuations in the power
supply can lead to a fault message.
–
T4 fuse defective
–
Check the environment circuit for
leaks
–
Top up the medium (brine-to-water),
purge
–
Check the screwed contact on the
PCB
–
Check that the pressure switch
works correctly
–
Replace the pressure switch
–
Check that the wiring of X110B with
X110 or X110A with X110 is correct
–
Eliminate any voltage fluctuations in
the network, e.g. via the site power
supply
–
Check the T4 fuse and replace if
necessary
F.788
Building circuit: Pump fault
–
The electronics system of the high-
efficiency pump has detected a
fault (e.g. dry running, blockage,
overvoltage, undervoltage) and has
switched off and locked the pump.
–
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 building circuit
F.789
Sensor fault: Fan unit 2 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.790
Sensor fault: Fan unit 2 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.792
Sensor fault: VI inlet temp.
–
Sensor not connected or sensor
input has short-circuited
–
Check the sensor, and replace if
necessary
–
Replace the cable harness
F.793
Sensor fault: EEV-VI outlet temp.
–
Sensor not connected or sensor
input has short-circuited
–
Check the sensor, and replace if
necessary
–
Replace the cable harness
F.797
Sensor fault: Cooling flow temp.
–
Sensor not connected or sensor
input has short-circuited
–
Check the sensor, and replace if
necessary
–
Replace the cable harness
F.798
Sensor fault: Well inlet temp.
–
Sensor not connected or sensor
input has short-circuited
–
Check the sensor, and replace if
necessary
–
Replace the cable harness
F.799
Sensor fault: Well outlet temp.
–
Sensor not connected or sensor
input has short-circuited
–
Check the sensor, and replace if
necessary
–
Replace the cable harness
F.1100
Immersion heater: Safety cut-out
open
The safety cut-out on the electric back-
up heater is open due to:
–
Insufficient volume flow or air in the
building circuit
–
The immersion heater is operated
when the building circuit is not filled
–
Immersion heater operation at flow
temperatures above 110 °C trips the
safety fuse of the safety cut-out and
requires that the fuse be replaced
–
Feed-in of external heat into the
building circuit
–
Check the circulation in the building
circuit pump
–
If required, open the stopcocks. The
safety cut-out is automatically reset
as soon as the temperature at the
fuse falls below 55 °C again.
Also press
reset
.
If the safety cut-out is still open at an
electric back-up heater temperature
below 55 °C, temperatures above
110 °C were reached and the safety
fuse tripped.
–
Replace the safety cut-out
–
Reduce or stop the external heat
that is entering