Logik washing machine error code E21

hi,

i have a logik washing machine displaying error code e21,

i have cleaned the filter, removed and cleaned the pump, removed and cleaned the sump hose but the problem persists - the pump is definitely working.

i feel like it could be a sensor problem as i know that there's not water in the machine and yet it's stilling trying to pump out?

i have taken out the water level switch and blown down the hose which doesn't seem to be blocked and i blew in to the sensor and could hear it clicking so i assume that would indicate its not at fault?

is there likely to be a drain sensor anywhere? could this type of problem be caused by a blocked pressure bottle?

thanks for any guidance.

jack