Operating instructions

ManualsBrandsViessmann ManualsHeat PumpVITOCAL 242-G

50

Message

System characteristics Cause Measures

29 Return sensor sec.

Operation with tempera-

ture value of flow temper-

ature sensor in secon-

dary circuit, minus 5 K. If

both temperature sen-

sors (secondary flow and

return) are faulty, the

heat pump stops (mes-

sage A9)

Break, secondary circuit

return temperature sen-

sor

Check resistance (Pt 500)

at plug-in connection F9

and terminals X5.10/

X5.11; replace sensor if

required.

30 Flow sensor primary

Operation with tempera-

ture value of return tem-

perature sensor in pri-

mary circuit, plus 3 K. If

both temperature sen-

sors (primary flow and

return) are faulty, the

heat pump stops (mes-

sage A9)

Short circuit, primary cir-

cuit temperature sensor,

brine inlet

Check resistance (Pt 500)

at plug-in connection F2

and terminals X5.2/X5.3;

replace sensor if

required.

31 Return sensor primary

Operation with tempera-

ture value of flow temper-

ature sensor in primary

circuit, minus 2 K. If both

temperature sensors

(primary flow and return)

are faulty, the heat pump

stops (message A9)

Short circuit, primary cir-

cuit temperature sensor,

brine outlet

Check resistance (Pt 500)

at plug-in connection F3

and terminals X5.4/X5.5;

replace sensor if

required.

38 Flow sensor primary

Operation with tempera-

ture value of return tem-

perature sensor in pri-

mary circuit, plus 3 K. If

both temperature sen-

sors (primary flow and

return) are faulty, the

heat pump stops (mes-

sage A9)

Lead break, primary flow

temperature sensor,

(brine inlet)

Check resistance (Pt 500)

at plug-in connection F2

and terminals X5.2/X5.3;

replace sensor if

required.

Troubleshooting

Messages

(cont.)

5441 603 GB