E13 is related to lint buildup in the Haier combo units covered by the source. It is not a universal drain or drying code for the entire brand.
Haier Appliances support for combo units documents that association. Before performing any cleaning, confirm that your model is included and that its manual allows the procedure.
The procedure depends on the combo unit
Check the maintenance history and whether the water connections required by the manual are available, including the power the unit needs during its cycles. Do not take a lack of water as proof that a specific filter is clogged.
The source recommends a specific cleaning for its units. Do not copy the product, dosage, or wash-and-dry combination to another washer-dryer. Also do not mix a descaler or cleaner with products already left in the dispenser.
Limit any intervention to the user maintenance access points, with the unit stopped and cooled down. If the manual does not confirm the cleaning for your model, request instructions from the manufacturer. If E13 persists after authorized maintenance, it requires service, without opening internal ducts.
When requesting help, keep E13 and the full model number, and explain what maintenance was performed; avoid describing it only as "lint in the filter."