Stiebel Eltron DHB 18 Si Instructions D'utilisation Et De Montage page 13

6. Fault-finding
- user
Fault
The heating system in the DHB does not
come on, despite the hot water tap being
opened fully.
7. Fault-finding
- qualified installer
Fault
Differential switch/flow regulator (MRS
switching system) does not come on,
despite the hot water tap being opened
fully.
No hot water, despite the fact that the diffe-
rential switch can be heard switching on.
Cause
The flow volume required to turn on the
heating system has not been attained.
– Dirt contamination or lime scale on the
percolators in the fittings or the shower
heads.
– Shower comfort switch in wrong position.
Cause
The flow volume required to turn on the
heating system has not been attained.
– Dirt filter (in ) blocked.
– Toothed bar (16) not engaged.
– The safety pressure limiter (AD 3) has
switched the device off for safety reasons
(pressure peak in the water installation
> 12 bar).
– Heating system defective.
Rectification
– Clean and/or descale.
– Move the shower comfort switch to the
latching position .
Rectification
– Clean the filter intake after unblocking the
cold water pipe.
– Remove the cover. Move the toothed bar
into the middle position and refit the
cover.
Rotate the shower comfort switch and
power selector switch to the left and right
stops (inner setting lever engages) and
bring it into the basic setting.
– Eliminate the cause of the fault (e.g.
defective pressure spray), press blue
button on the safety pressure limiter
(11 a), but only with the tap open and the
device free of pressure.
– Replace heating system.
13