F.326
The hydraulic sensor and actuator test has detected at least two hydraulic components that are not working.
Vaillant ecoTEC Plus System
Possible cause
3-port diverter valve defective or blocked
Measure
Check and, if required, replace the 3-port diverter valve.
Possible cause
Plug on 3-port motorised valve loose/not plugged in
Measure
Check the plug and the plug connection on the 3-port motorised valve.
Possible cause
Interruption in the wiring harness
Measure
Check the wiring harness including all plug connections and, if required, replace it.
Possible cause
Domestic hot water circuit not connected
Measure
Connect the domestic hot water circuit.
Possible cause
External pump runs continuously
Measure
Check the external pump and the system configuration.
Possible cause
The pump is defective.
Measure
Check and, if required, replace the pump.
This code also applies to: