Flow Sensor Hc3 - Viessmann VITOTRONIC 200 Service Instructions Manual

Troubleshooting
Message overview

49 Flow sensor HC3

Mixer heating circuit M3/HC3 is closed.
Cause
Lead break, flow temperature sensor, heating circuit
with mixer M3/HC3
4B Flow sensor system
■ Flow temperature in heating circuit without mixer
A1/HC1 is regulated via the return temperature sen-
sor of the heat pump, no frost protection for this
heating circuit.
■ Mixer external heat generator does not open.
Cause
Lead break, system flow temperature sensor (down-
stream of buffer cylinder)
4C Flow sensor cooling
If "Enable flow temperature sensor cooling circuit
7109" is set to "0", cooling operation is possible, oth-
erwise no cooling.
Cause
Lead break, flow temperature sensor, cooling circuit
50 Cylinder sensor top
■ If only the upper cylinder temperature sensor is
present: No DHW heating
If an additional lower temperature sensor is installed:
■
DHW heating possible, switched on and off via this
sensor
Cause
Short circuit, top cylinder temperature sensor
52 Cylinder sensor bottom
If only the lower cylinder temperature sensor is
■
present: No DHW heating
■ If an additional upper temperature sensor is installed:
DHW heating possible, switched on and off via this
sensor
84
(cont.)
Measure
Check sensor: See mixer extension kit installation in-
structions.
Measure
Check resistance value (NTC 10 k
■
"Controller and sensor PCB".
If system flow temperature is not required: Check
■
whether this sensor has been unintentionally activa-
ted ("Common flow temperature sensor system
701B").
Measure
Check resistance value (NTC 10 k
"Controller and sensor PCB".
Measure
Check resistance value (NTC 10 k
terminals X25.5/X25.6: See "Controller and sensor
PCB".
) at plug F13: See
Ω
) at plug F14: See
Ω
) at plug F6 or at
Ω