Viessmann VITOCAL 242-S Installation And Service Instructions Manual page 91

Repairs
(cont.)
? Secondary circuit flow tempera-
ture sensor (alternative posi-
tions)
%A Solar circuit return temperature
sensor
aJ Secondary circuit return tem-
perature sensor
sG Secondary pump
lJ 3-way diverter valve for "Central
heating/DHW heating"
a:DB PWM signal, secondary pump
a:DC PWM signal, cylinder loading
pump
A Cylinder temperature sensor
B Non-return valve
C DHW cylinder drain & fill valve:
See following chapter.
D Instantaneous heating water
heater with high limit safety cut-
out
E Secondary circuit drain & fill
valve
F
Service valve, internal unit:
Schrader valve, can be used in
place of the external unit service
valve for pressure checks and
evacuating the refrigerant cir-
cuit; see page 66.
G Liquid gas temperature sensor
(IRT)
H Secondary circuit flow tempera-
ture sensor, upstream of instan-
taneous heating water heater
(LWT)
K Secondary circuit air vent valve
L Pressure sensor (ICT) for deter-
mining condensation tempera-
ture in condenser
Troubleshooting
91