Viessmann VITOCAL 250-A - Page 161

161
Measures
1. Check configuration of external heat generator.
2. Check the following connections to the HIO elec-
tronics module:
■
52.1/52.2/52.4
■
TS1.1/TS1.2
■
Check wires and plugs for correct seating.
■
Check connections for contact corrosion.
■
Check cables for mechanical damage, e.g. crush-
ing, kinking, chafing or breakage.
3. Check whether the external 3/2-way mixing valve
opens and closes.
4. Check resistor R for NTC 10 kΩ on disconnected
plug TS1.
5. Replace 3/2-way mixing valve for dual mode opera-
tion.
F.1050 Short circuit, temperature sensor, external heat/cooling generator 1
F.1050
System characteristics
Unregulated operation of the external heat generator
Cause
Short circuit, boiler temperature sensor of external
heat generator
Measures
1. Check the sensor and connection TS2.1/TS2.2 on
the HIO electronics module:
■
Check wires and plugs for correct seating.
■
Check connections for contact corrosion.
■
Check cables for mechanical damage, e.g. crush-
ing, kinking, chafing or breakage.
2. Check resistor R for NTC 10 kΩ on the disconnected
plug. If R < 500 Ω, replace the sensor.
3. Replace HIO electronics module.
F.1051 Lead break, temperature sensor, external heat/cooling generator 1
F.1051
System characteristics
Unregulated operation of the external heat generator
Cause
Lead break, boiler temperature sensor of external heat
generator
Measures
1. Check connection TS2.1/TS2.2 on the HIO electron-
ics module:
■
Check wires and plugs for correct seating.
■
Check connections for contact corrosion.
■
Check cables for mechanical damage, e.g. crush-
ing, kinking, chafing or breakage.
2. Check resistor R for NTC 10 kΩ on the disconnected
plug. If R > 300 kΩ, replace the sensor.
3. Replace HIO electronics module.
F.1054 Maximum temperature, external heat/cooling generator 1 exceeded
F.1054
System characteristics
External heat generator not ready for operation
Further message: A.110
Cause
Max. boiler water temperature of external heat genera-
tor exceeded
Measures
Check external heat generator. Remedy any fault. If
necessary, reset high limit safety cut-out:
See installation and service instructions for external
heat generator
Messages
Fault messages (cont.)
6218234
Diagnosis