Trouble-Shooting - STIEBEL ELTRON DHC 3 U Gebrauchs- Und Montageanweisung

Elimination of faults by the user
Fault
No hot water despite the hot water fitting
being fully opened.
Table 3
Elimination of faults by the qualified installer
Fault
The differential pressure switch is not
switching the heating on despite the hot
water fitting being fully open.
Despite the appropriate sound being
audible from the differential pressure
switch as if it were switched on, no hot
water is flowing.
Overheating light is showing.
Table 4
28
Cause
The water flow rate required for the system
to switch on has not been achieved (see
Table 2).
– Dirt contamination or limescale
formation in the flow regulator in the
fitting or in the shower head.
Cause
The water flow rate required for the system
to switch on has not been achieved (see
Table 2).
– Filter in differential pressure switch is
blocked.
– Flow rate too small.
– The safety thermal cut-out has switched
the unit off for safety reasons.
– Heating element clogged with limescale
(caused by heat thermal cut-out build-up).
– Heating element defective.
– Flow rate too small.
Rectification
– Cleaning or descaling of the flow
regulator in the fitting or in the shower
head.
Rectification
– Clean the filter (Fig. 20, Item 6) after
shutting off the cold water cable entry.
– Correct the flow rate setting (Fig. 18).
– Eliminate the cause of the fault. Press
the reset button on the safety thermal
cut-out (Fig. 21, Item 7). The current
to the unit must be disconnected.
– Replace heating element
– Replace heating element
– Correct the flow rate setting (see Fig. 18
and Table 1).