Err2 indicates a drainage failure in the Haier combo units in the referenced table. E2, without Err, refers to the door lock and must be interpreted separately.
The Haier Appliances documentation points Err2 to drainage and the filter. Access must match the manual for the installed model.
With water still inside, first prepare the drain
Check whether the external hose is kinked or inserted too far into the drain. An incorrect connection can make drainage difficult; correct the setup according to the manual, without removing any appliance fasteners as a test.
If the unit has a user-accessible filter, stop and unplug the washer-dryer and let the water cool. Prepare the residual draining procedure indicated before loosening the filter. Opening it suddenly with the tub full can release a lot of water.
If the hose and the approved filter are clear and Err2 returns, request a circuit inspection. Hearing the pump does not prove there is enough flow, and the alarm alone is not enough to condemn the pump or the control board.
When contacting support, distinguish whether the unit did not drain at all or whether water remained after a partial drain.