What the symptom can mean
A tank warning can concern collection or drainage behaviour, not only the removable container itself. Existing hose arrangements and the precise indication help direct checks.
Copy the indication
Write down the tank symbol or wording and when it appears. Say whether it comes before tumbling, during drying or at the finish. Mention whether the machine still runs after the indication.
Describe existing drainage
If the dryer normally sends water through a hose, include that fact and any recent work nearby. Keep tank observations separate from assumptions about where the fitted water route goes.