22
Tanks cool down at night
Collector circuit pump
runs during the night?
no
yes
Check controller:
Manual operation active?
Tube collector function
active? Tank cooling or
antifreeze function active?
Collector temperature is at
night higher than the out-
door temperature
no
yes
Check the check valve in
the flow and the return
pipe with regard to the
functional efficiency.
Sufficient tank insulation?
yes
no
Increase insulation.
Insulation close enough to
the tank?
yes
no
Replace insulation or
increase it.
Are the tank connections
insulated?
yes
no
Insulate the connections.
Warm water outflow
upwards?
no
yes
Change connection and
let the water flow hori-
zontally or through a
siphon (downwards); less
tank losses now ?
Does the warm water
circulation run for a very
long time?
no
yes
Use the circulation pump
with timer and switch-off
thermostat (energy efficient
circulation).
The solar circuit pump does not work, although the collector
is considerably warmer than the tank.
Is the control lamp (LED)
illuminated?
yes
no
Does the pump start up in
manual operation?
yes
There is no current; check
fuses / replace them and
check power supply.
The adjusted temperature
difference for starting the
pump is to high; choose a
value which makes more
sense.
no
Is the pump current
enabled by the controller?
yes
Is the pump stuck?
Tu rn t h e p u m p s haf t
using a screwdriver; now
passable?
Pump is defective - replace
it
Are the controller fuses
o.k. ?
C o n t r o l l e r m i g h t b e
defective - replace it or
contact the distributor.
no
yes
no
no
yes
Replace fuses.
Circulation pump and
blocking valve should be
switched off for one night;
less tank losses?
yes
no
Check whether the pumps
of the backup heating
circuit run at night; check
whether the non-return
valve is defective; problem
solved ?
no
no
yes
o.k.
Control the non-return
va lve i n w a rm w a t e r
circulation - o.k.
yes
no
Further pumps which are
connected to the solar tank
must also be checked.
The thermosiphoning in
the circulation line is too
strong; insert a stronger
valve in the non-return
valve or an electrical 2-port
valve behind the circulation
pump; the 2-port valve is
open when the pump is
activated, otherwise it is
closed; connect pump and
2-port valve electrically
in parallel; activate the
circulation again
Clean or replace it
a
a
b
b
yes
o.k.
