Short Circuit Sensor 3 Pump Module; Short Circuit Sensor 4 Pump Module; Lead Break Sensor 1 Pump Module; Lead Break Sensor 2 Pump Module - Viessmann PM1 Installation And Service Instructions Manual

Diagnosis and fault messages
Fault messages
(cont.)
Cause
Temperature sensor 2 short circuit

76 Short circuit sensor 3 pump module

Control with 150 °C actual boiler water temperature for
function 2 (parameter "03:2") or function 6 (parameter
"03:6")
Cause
Temperature sensor 3 short circuit

77 Short circuit sensor 4 pump module

Control with 0 °C actual buffer temperature for function
5 (parameter "03:5") or function 6 (parameter "03:6")
Cause
Temperature sensor 4 short circuit
7C Lead break sensor 1 pump module
Dependent on use of temperature sensor at pump
module connection S1:
For return temperature control with function 3
■
(parameter "03:3") or function 7 (parameter "03:7"):
Control with 0 °C return temperature
■ For flow temperature control with function 4 (parame-
ter "03:4"):
Control with 150 °C flow temperature
Cause
Temperature sensor 1 lead break
7D Lead break sensor 2 pump module
Dependent on use of temperature sensor at pump
module connection S2:
For return temperature control with function 3
■
(parameter "03:3") or function 7 (parameter "03:7"):
Control with 0 °C return temperature
■ For flow temperature control with function 4 (parame-
ter "03:4"):
Control with 150 °C flow temperature
38
Measure
Check temperature sensor: See chapter "Checking the
temperature sensors".
Replace temperature sensor if necessary.
Measure
Check temperature sensor: See chapter "Checking the
temperature sensors".
Replace temperature sensor if necessary.
Measure
Check temperature sensor: See chapter "Checking the
temperature sensors".
Replace temperature sensor if necessary.
Measure
Check temperature sensor: See chapter "Checking the
temperature sensors".
Replace temperature sensor if necessary.