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INSTALLATION
Troubleshooting
13. Troubleshooting
WARNING Electrocution
To test the appliance, it must be supplied with power.
Indicator options for diagnostic traffic light (LED)
Red
Illuminates in the event of a fault
Yellow
Illuminates during heating operation
Green
Flashing: Appliance connected to
power supply
13.1 Fault table
Fault / LED diagnostic traffic light signal Cause
Remedy
The appliance does not start.
The shower head/aerators are scaled up.
Descale or if necessary replace the shower head /
aerators.
The flow rate is too low.
The strainer in the appliance is dirty.
Clean the strainer.
The temperature is not achieved.
One phase down.
Check the fuse/MCB in your fuse box/distribution
board.
The heating system does not switch on.
The air sensor detects the presence of air in the water
and briefly switches the heater off.
The appliance restarts after one minute.
No hot water and no traffic light display.
The MCB/fuse has responded/blown.
Check the fuse/MCB in your fuse box/distribution
board.
The safety pressure limiter (see chapter "Installation /
Specification / Wiring diagram" has switched off.
Remove the cause of the fault (e.g. faulty pressure
washer).
Protect the heating system against overheating by
opening a draw-off valve downstream of the appli-
ance for one minute. This depressurises and cools
down the heating system. Activate the safety pressure
limiter at flow pressure by pressing the reset button,
also see chapter "Installation / Commissioning / Ini-
tial start-up".
The PCB is faulty.
Check the PCB and replace if required.
No hot water at flow rate of > 2.3 l/min.
Traffic light display: green flashing.
The PCB is faulty.
Check the PCB and replace if required.
The flow sensor is not plugged in.
Re-insert the flow sensor plug.
The flow sensor is faulty.
Check the flow meter/flow sensor and replace if re-
quired.
No hot water at flow rate of > 2.3 l/min.
Traffic light display: yellow constantly on; green
flashing.
The high limit safety cut-out has responded (see
chapter "Installation / Specification / wiring diagram"
or has suffered a break in continuity.
Check the high limit safety cut-out and replace it if
required.
The heating system is faulty.
Check the resistance of the heating system, and re-
place if required.
The PCB is faulty.
Check the PCB and replace if required.
No hot water.
Traffic light display: red constantly on; green flashing.
The cold water inlet temperature exceeds 35 °C.
Reduce the cold water inlet temperature to the ap-
pliance.
The cold water sensor is faulty.
Check the PCB and replace if required.
14. Maintenance
WARNING Electrocution
Before any work on the appliance, disconnect all poles
from the power supply.
Draining the appliance
The appliance can be drained for maintenance work.
WARNING Burns
Hot water may escape when you drain the appliance.
f
f
Close the shut-off valve in the cold water inlet line.
f
f
Open all draw-off valves.
f
f
Undo the water connections on the appliance.
f
f
Store the dismantled appliance in a room free from the risk
of frost, as water residues remaining inside the appliance can
freeze and cause damage.