Viessmann Vitocal 300-G BW, Installation And Service Instructions Manual

Page: 124 / 216

124
ID Message (pri-
ority) 1. Cause
2. Measures Access right
D4 Control high
pressure ("i") 1. Air in the heating circuit; secondary or
heating circuit pump blocked; con-
denser contaminated; pressure sensor
faulty
2. Vent heating circuit; check secondary
and heating circuit pump; flush heating
circuit; check system pressure
Contractor
D6 Flow switch
("
U
")
1. The flow switch has responded; inade-
quate throughput
2. Check primary pumps and circulation
pump for brine/primary circuit. For
type WW/WWC check filter and inter-
mediate circuit heat exchanger; check
primary circuit pressure
Customer
E1 Ext. Heat gen-
eration ("
U
")
1. Fault on the external heat source
2. Check external heat source Customer
E2 Fault, lag heat
pump ("
U
")
1. Fault at the lag heat pump in a cascade
2. Check the lag heat pump display Customer
FF New start ("i") 1. Control unit restart
2. No measures required Customer
Heat pump characteristics in case of messages
All messages have a 2-digit number as identifier, the so-called "ID". This number
corresponds to the ID in the table above "Message display" from page 114.
ID Characteristics and effects of system/control unit
10
18 Outside temperature is assumed to be -40 °C.
20
28 The temperature value of the secondary return sensor plus 5 K is selected.
The heat pump is stopped (message A9) if the secondary flow and return
temperature sensors are faulty.
21
29 The temperature value of the secondary flow sensor plus 5 K is selected.
The heat pump is stopped (message A9) if the secondary flow and return
temperature sensors are faulty.
30
31
38
39 The heat pump will not start.
Troubleshooting
Control unit diagnostics
(cont.)
5368 522 UAE