D6 Flow Switch - Viessmann VITOTRONIC 200 Service Instructions Manual

Message overview
(cont.)

D6 Flow switch

Compressor stops.
Cause
Minimum flow rate in secondary circuit is undershot:
See heat pump specification.
Heat pump specification
Heat pump installation and service instructions
D7 Flow switch
Heat pump does not start.
Cause
Flow switch faulty
■
Flow switch is sticking.
■
Jumper across X3.3/X3.4 is inserted.
■
E0 LON subscriber
No communication with the subscriber via LON
Cause
Connection to LON subscriber is faulty.
E1 External heat source
Heat pump control unit cannot start external heat
source.
Cause
External heat generator fault
■
Short circuit/lead break, boiler water temperature sen-
■
sor in external heat generator
Measure
Check secondary circuit flow rate.
■
Check secondary pump.
■
If no flow switch is installed, insert a jumper across
X3.3/X3.4: See "Luster terminals" or "Cross connect
PCB".
The flow switch signal can be checked against X2.N at
terminal 216.3 (see "Main PCB") or at terminals X3.3/
X3.4.
0 V Flow switch has responded.
230 V~ Flow switch has not responded.
Measure
Check flow switch.
■
Remove jumper between X3.3/X3.4. Connect flow
■
switch: See "cross connect PCB" or "luster terminals".
Action
Carry out subscriber check (See "LON subscriber
■
check").
Check system and subscriber numbers ("LON sys-
■
tem number 7798", "LON subscriber number
7777").
Check connections and LON connecting lines.
■
Measure
Check external heat source.
■
Check resistance value (NTC 10 k
■
"Controller and sensor PCB".
Troubleshooting
) at plug F20: See
Ω
101