Viessmann VITOTRONIC 200 Service Instructions Manual page 48

Troubleshooting
Messages
(cont.)
Message
Code/system characteris-
tics
7B Room temp. sensor SKK
No cooling mode.
92 Collector temp. sensor
No solar DHW heating.
93 Retn temp.sensor solar
No solar DHW heating.
48
Cause
Lead break, room tem-
perature sensor, cooling
circuit.
With integral solar control function:
■ Short circuit, collector
temperature sensor.
With the Vitosolic:
■ Short circuit, Vitosolic
collector temperature
sensor.
With integral solar control function:
■ Short circuit, return
temperature sensor.
With the Vitosolic:
■ Short circuit, Vitosolic
cylinder temperature
sensor.
Measures
Check resistance (Ni 500)
at plug-in connection F16
(see page 172); replace
sensor if required.
■ Check resistance
(Pt 500) at plug-in con-
nection F21 (see
page 172); replace
sensor if required.
■ Check sensor and
replace if required (see
Vitosolic installation and
service instructions).
■ Check resistance
(Pt 500) at plug-in con-
nection F18 (see
page 172); replace
sensor if required.
■ Check sensor and
replace if required (see
Vitosolic installation and
service instructions).