Viessmann VITOCAL 300 Installation And Service Instructions Manual page 62

Troubleshooting
Control unit diagnostics
Fault messages
C4 Power-OFF con-
tact
C8 Safety chain
C9 Refrigerant cir-
cuit
CA Primary pump
CB Primary tempera-
ture
D1 Compressor
D3 Low pressure 1
62
(cont.)
Cause
Power-OFF contact en-
abled longer than 12 h
Fault at one of the con-
nected components
The flow switch has re-
sponded (flow rate too
low)
Safety high pressure
limiter has responded
Thermal overload relay
of the primary pump
has responded
Primary inlet tempera-
ture below its minimum
level
The thermal overload
relay of the compressor
has responded
Primary circuit leaks or
primary pump faulty
Intermediate circuit
leaks or intermediate
circuit pump faulty
Heat pump faulty
Measures
Check the Power-OFF con-
version kit (accessory) and
replace it, if required
Check the external safety
chain, connected compo-
nents and circuits
Primary pumps:
Check the circulation pump
for the brine circuit or the
submersible pump
Check the flow and return
temperature sensors,
check the primary and sec-
ondary circuits for pressure
and throughput; ask your
local refrigeration engineer
to check the heat pump, if re-
quired
Reset the thermal overload
relay, check the primary
pump (see page 50) and re-
place it, if required
Check the brine circuit for
throughput
Reset the thermo-relay,
check the setting, perform a
reset, check the connection,
check the coil resistance,
adjust the phase sequence
at the compressor.
Reset the pressure switch.
Check the pressure gauge,
primary pump and shut-off
facilities.
Check pressure gauge and
intermediate circuit pump
Have the heat pump tested
by a refrigeration engineer