Stiebel Eltron SOM 6 PLUS Utilisation Et Installation page 30

Cylinders cool down over night.
Collector circuit
pump runs at night?
Check the
no yes
controller
function.
At night the collector
temperature is higher
Check non-return
than the outside
valves in the
temperature.
flow and return
to ensure they
yes
no
are operating
correctly.
Cylinder insulated
adequately?
Improve
yes no
insulation.
Cylinder insulation
tightly fitted?
Replace or
improve
yes no
insulation.
Cylinder connections
insulated?
Insulate
yes no connections.
Change
DHW outlet through
connection to the
the top?
side or use siphon
design (bend
no yes
pointing down);
are cylinder losses
now lower?
no
DHW circulation
runs for a very long
time?
Use DHW circulation
no yes
pump with time
switch and stop
thermostat (energy
Switch OFF DHW
efficient DHW
circulation pump
circulation).
and shut-off valves
for one night; are
Check pumps of
cylinder losses
reheating circuit
reduced?
for night running
and check faulty
yes no
non-return valve;
does this solve the
problem?
Check non-return valve
in DHW circulation - OK.
yes no
Excessive natural circulation in the
DHW circulation line; use more
powerful non-return valve or fit an
electric two-way valve downstream of
the DHW circulation pump; the two-
way valve is open when the pump is
operating; it is closed at other times;
connect pump and the two-way valve
electrically in parallel; start up DHW
circulation again. Speed control must
be disabled.
30
The solar circuit pump does not run although
the collector is considerably warmer than the
cylinder.
LED indicators
illuminated on the
controller?
yes
Does the pump start
in manual mode?
no
Is pump power
enabled by the
controller?
no
Controller fuses OK?
no
Replace the fuse.
yes
OK
no
Also check
further
pumps
connected
to the
solar
cylinder.
Clean or
replace.
No power
supply; check
/ replace fuses
and check power
supply.
no
temperature
differential set
too high to
yes
switch ON pump:
set to a sensible
figure.
Pump seized?
yes
yes
Move pump shaft
with screwdriver:
will it move
now?
no
yes
Pump faulty -
replace.
Controller faulty
- replace.