32
Red LED on the heat pump control unit
Fig. 24
A
Red LED
Signal
Cause
Action
Flashes briefly
every 10 s.
No fault
No action required
Flashes in a dif-
ferent se-
quence.
Fault
See message on the programming unit
Constantly off
No power supply
Restore power supply.
Messages on the programming unit
Message
Cause
Action
"ER 1"
Safety high pressure switch has responded.
Overpressure in the heat pump circuit.
Switch power supply OFF and ON again.
or
Acknowledge message. See the following
chapter.
"ER 2"
High limit safety cut-out has responded.
Overheating of the DHW cylinder.
Ensure DHW is being drawn.
Reset high limit safety cut-out (see
page 34).
"ER 3"
Short circuit/lead break in lower cylinder temper-
ature sensor
Check resistance value and replace sensor
if necessary (see page 36).
"ER 4"
Short circuit/lead break in air intake temperature
sensor
"ER 5"
Short circuit/lead break in evaporator tempera-
ture sensor
"ER 8"
Communication problem between programming
unit and heat pump control unit
Check connections and cables.
Acknowledging messages
Press and hold
and
OK
simultaneously for 3 s to
clear a message and resume standard operation.
Troubleshooting
Messages
5788 057 GB
Diagnosis
