Viessmann VITOSOLIC 200 Installation And Service Instructions Manual page 91

Fault messages
Very large temperature differential between the collector array and consumers
during operation (heat cannot be dissipated):
Solar circuit pump faulty? ⇒
No
Solar heat exchanger scaled up? ⇒
No
Solar heat exchanger blocked?
⇒
No Yes
Solar heat Flush the solar
exchanger thermal sys-
sized too small. tem (see col-
lector service
instructions).
The solar circuit pump does not run, although the temperature in the collector
array is higher than that in the consumer.
Display dark?⇒
Yes
■ Check the operating voltage (ON/OFF
switch, power cable).
■ Check fuse F1, 6.3 A (slow).
If fuse F1 is faulty; replace it (see
page 93).
(cont.)
Yes
Descale solar
heat
exchanger.
Yes
Check the solar circuit pump:
■ Check the operating voltage
(ON/OFF switch, power
cable).
■ Check fuse F1, 6.3 A (slow).
If fuse F1 is faulty; replace it
(see page 93).
No
Check whether the solar circuit pump
runs in manual mode (see page 84).
No
Is pump current enabled
by the solar control unit?
⇒
No Yes
Check fuse Solar circuit
F1, 6.3 A pump
(slow). seized.
If fuse F1 is Free the
faulty; pump shaft.
replace it Replace the
(see pump if it
page 93). refuses to
Otherwise run.
replace
solar con-
trol unit.
Troubleshooting
Yes
Start tem-
perature dif-
ferential
"ΔTon" too
great?
If yes,
change
value (see
page 151).
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