Appendix
32
Installation and maintenance instructions auroFLOW plus 0020149486_04
B
Connection diagram
SMU
X1
X2
X3
X4
X5
X6
X7
X8
eBus
HMU
X51
HMU
X51
P1
P2
P3
T6
T5
eBus
UV5
230VAC
T3
T1
T2
T4
flow
STW1
STW2
C
Detecting and rectifying faults
Fault
Possible cause
Explanation/remedy
The pumps start up at irregular intervals,
including at night
Blockage prevention function
No fault
Collectors are warmer than the cylinder,
but the solar plant does not start
Cylinder is charged
or a forced pause of 10 minutes is activ-
ated after the pump stops
No fault
Increase maximum cylinder temperature if
required
Storage tank remains empty if the solar
pump is idle
Collector field cannot drain
Draining of the collector field can last up to
15 min
Check the solar circuit for siphons
Cylinder charging pump is running, how-
ever the solar pump is not running
Overrun function (solar charging stopped
shortly before)
No fault
Cylinder charging pump running at low
outside temperatures
Frost protection function
No fault
Collector temperature very high and solar
system starts filling
Hot starts are possible as a result of Drain-
back technology
No fault
Solar pump sucks air in
Fluid level too low
Top up the solar fluid until it reaches the '2'
mark when in circulation
Solar pump sucking in air, as the flow
of fluid from the second storage tank is
delayed
Minimal pressure loss in the solar circuit in
combination with excessive pressure loss
in the connection pipes between the basic
and expansion module
Check the connection pipes for block-
ages/kinks, reduce the pump output of the
first solar pump in the solar control and
increase the delay before the second solar
pump is activated
