Viessmann Vitocal 242-S Installation And Service Instructions Manual page 97

Repairs
(cont.)
? Secondary circuit flow tempera-
ture sensor (alternative posi-
tions)
%A Return temperature sensor,
solar circuit
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 for cylinder primary
pump
A Cylinder temperature sensor
B Non-return valve
C 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
Internal unit service valve
(Schrader valve; can be used in
place of the external unit service
valve for checking pressure and
evacuating the refrigerant cir-
cuit; see page 72)
G Liquid gas temperature sensor
(IRT)
H Secondary circuit temperature
sensor upstream of the 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
97