14
LED
Meaning
Cause
Action
Illuminates green
Circulation pump in opera-
tion
—
—
Flashes green in short in-
tervals
RKA version
*1
:
Pump runs for 10 min in
the venting function.
Then set the required out-
put.
—
—
PWM version
*2
:
Pump on standby
—
—
Fault indications
■
Flashes red and green
alternately
Pump is ready for opera-
tion but does not run.
Note
The circulation pump
starts automatically after
the cause of the fault has
been removed.
■
Undervoltage (< 160 V~)
■
Overvoltage (> 253 V~)
Check power supply
(195 V~ < U < 253 V~)
Motor temperature too
high
Check ambient and heat
transfer medium tempera-
tures.
■
Flashes red
Circulation pump switched
off (blocked)
Circulation pump does not
start automatically.
Replace the circulation
pump.
■
Is OFF
—
No power.
Check connecting cable.
LED faulty
Check whether the circula-
tion pump is running.
PCB faulty
Replace the circulation
pump.
*1
Version with operating button for variable and constant differential pressure.
*2
Version with control via PWM signal.
Display and troubleshooting
LED at the HE circulation pump
5549 892 GB