OPERATION
Troubleshooting
14. Troubleshooting
WARNING Electrocution
Never remove or reinstall the water heater's cover
unless the electricity servicing the unit is turned off.
Failure to do so could result in personal injury or death.
WARNING Electrocution
To test the water heater using the internal diagnostic
lights, it must be connected to the power supply.
When testing with the cover off, never touch any part
of the water heater. Doing so could result in serious
personal injury or death.
Note
When testing the water heater using the diagnostic lights,
water must be flowing through the unit.
Diagnostic lights
Red
Lights up in the event of a fault
Yellow
Lights up in heating mode/flashes when output limit
reached
Green
Flashing: Water heater connected to power supply
Diagnostic lights
Problem
No LED is lit
The water heater does not
heat up
Green flashing, yellow
No DHW
off, red off
Green flashing, yellow
The outlet temperature does
on, red off
not match the set value
Green flashing, yellow
No DHW
off, red on
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Cause
There is no power
The PCB is faulty
The shower head/aerator is scaled up
The filter screen in the cold water inlet is dirty
The flow meter is not plugged in
The flow meter is faulty
The PCB is faulty
The device is connected to a power supply <240 V
The tap is faulty
The heating system is faulty
The PCB is faulty
Air detected
AE3 safety switch not activated during commission-
ing
AE3 safety switch triggered by high limit safety
cut-out
AE3 safety switch responds again after high limit
safety cut-out has been checked; high limit safety
cut-out faulty
Safety switch responds again; PCB faulty
PCB faulty (lead break or short circuit in inlet sen-
sor)
Solution
Check to ensure the connected circuit breaker in
the main breaker panel hasn't tripped. Reset if
necessary
Replace the function module
Descale or replace the shower head/aerator if nec-
essary
Clean the filter screen. See section 15.2, "Cleaning
the filter screen", pg. 16
Connect the cable to the PCB
Replace the function module
Replace the function module
Please observe the information in section 10.2,
"Temperature setting via jumper slot - operating
voltage 240 V", pg. 11
Replace the tap
Replace the function module
Replace the function module
Continue draw-off for >1 minute
Activate AE3 safety switch by pressing the reset
button firmly. See section 10.3.1, "Initial AE3 safety
switch activation", pg. 11
Check high limit safety cut-out (plug-in connection,
connecting cable); activate AE3 safety switch
Replace high limit safety cut-out; activate AE3 safety
switch and draw off water at the maximum set value
for >1 min
Replace the function module
Replace the function module
DCE Trend|
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