Viessmann VITOCAL 350-A, Installation And Service Instructions Manual

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135
Message
System characteristics Cause Measures
«
30 Flow sensor primary
The heat pump will not
start Short circuit, air inlet tem-
perature sensor Check resistance (Pt 500)
at connections 3X1.24
and 3X2.24; replace sen-
sor if required.
«
31 Primary return sens.
The heat pump will not
start Short circuit - air dis-
charge temperature sen-
sor Check resistance (Pt 500)
at connections 3X1.23
and 3X2.23; replace sen-
sor if required.
«
32 Evaporator sensor
Short circuit - evaporator
temperature sensor Check pressure drop
value (type Pt 500) at con-
nections 3X1.5 and
3X2.5; replace sensor if
required.
«
33 Hot gas
Short circuit - hot gas
temperature sensor Check pressure drop
value (type Pt 500) at con-
nections 3X1.1 and
3X2.1; replace sensor if
required.
«
38 Flow sensor primary
The heat pump will not
start Break - air inlet tempera-
ture sensor Check resistance (Pt 500)
at connections 3X1.24
and 3X2.24; replace sen-
sor if required.
«
39 Primary return sens.
The heat pump will not
start Break - air discharge
temperature sensor Check resistance (Pt 500)
at connections 3X1.24
and 3X2.24; replace sen-
sor if required.
Troubleshooting
Control unit diagnostics
(cont.)
5414 828 GB
Service