F.024
The temperature increases too quickly.
Vaillant ecoTEC Plus Combi
Possible cause
Air in the product
Measure
Purge the heating installation.
Possible cause
System pressure too low
Measure
Check the system pressure.
Possible cause
Fault in the electrical connection for the flow temperature sensor
Measure
Check and, if required, replace the wiring harness between the PCB and sensor, including all plug connections.
Possible cause
Fault in the electrical connection for the return temperature sensor
Measure
Check and, if required, replace the wiring harness between the PCB and sensor, including all plug connections.
Possible cause
Flow temperature sensor defective
Measure
Check and, if required, replace the flow temperature sensor.
Possible cause
Return temperature sensor defective
Measure
Check and, if required, replace the return temperature sensor.
Possible cause
Pump blocked
Measure
Check that the pump is working correctly.
Possible cause
Pump runs with insufficient output
Measure
Check that the pump is working correctly.
Possible cause
3-port diverter valve defective or blocked
Measure
Check and, if required, replace the 3-port diverter valve.
Possible cause
Internal expansion vessel defective
Measure
Check and, if required, replace the internal expansion vessel.
This code also applies to: