Troubleshooting - Stiebel Eltron DHX 3.5-1 Trend Funcionamiento E Instalación

INSTALLATION

Troubleshooting

16. 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.
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 display on the program-
on, red off ming unit is off
Green flashing, yellow The outlet temperature does
on, red off not match the set value
Plus models only: The outlet temperature does
Green flashing, yellow not match the set value
flashing, red off
Green flashing, yellow No DHW
off, red on
Diagnostic lights Display readout
Plus models only: Wrench flashes (displays
Green flashing, yellow E1 and wrench in menu
off, red on "Fault code display")
Wrench flashes (displays
E2 and wrench in menu
"Fault code display")
Wrench flashes (displays
E3 and wrench in menu
"Fault code display")
20 | DHX Trend & DHX Plus
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 sensor is not plugged in
The flow sensor is faulty
The PCB is faulty
There is a loose cable between the PCB and the pro-
gramming unit
The cable of the programming unit is faulty
The programming unit PCB is faulty
The PCB is faulty
The programming unit was not plugged in before
power was switched on
The outlet sensor is faulty
The tap is faulty
The heating system is faulty
The PCB is faulty
Motorized valve limit reached
Motorized valve is faulty
Air detected
Problem Cause
No DHW AE3 safety switch not activated during
commissioning
AE3 safety switch triggered by
self-resetting high limit safety cut-out
Klixon
AE3 safety switch responds again after
high limit safety cut-out Klixon has been
checked; high limit safety cut-out faulty
Safety switch responds again; PCB faulty Replace the PCB
No DHW PCB faulty (lead break or short circuit in
inlet sensor)
No DHW Short circuit in outlet sensor
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 an error
Yellow Lights up in heating mode/flashes when output limit
reached
Green Flashing: Water heater connected to power supply
Solution
Check to ensure the connected circuit breaker in the main
breaker panel hasn't tripped. Reset if necessary
Replace the PCB
Descale or replace the shower head/aerators if necessary
Clean the filter screen
Connect the cable to the PCB
Replace the flow sensor
Replace the PCB
Check the cable and plug the cable into the programming
unit and/or PCB
Check the cable and replace if necessary
Replace the programming unit, only available with a new
heater cover
Replace the PCB
Perform a reset by switching off the power to the water
heater
Replace the outlet sensor
Replace the tap
Replace the heating system
Replace the PCB
Reduce the set temperature
Replace the motorized valve
Continue draw-off for >1 minute
Solution
Activate AE3 safety switch by pressing the reset button
firmly. See section 12.2.1, "Initial AE3 safety switch acti-
vation," pg. 18
Check high limit safety cut-out, Klixon (plug-in connec-
tion, connecting cable); activate AE3 safety switch
Replace high limit safety cut-out Klixon activate AE3 safe-
ty switch and draw off water at the maximum set value
for >1 min
Replace the PCB
Check the outlet sensor, replace if necessary
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