A cold-wash selection can intentionally avoid the heated washing stage used by other programmes. The control choice must be checked before interpreting cool laundry or a cool door as evidence of heater failure.
Understanding this situation
The outside door temperature is an imperfect indication of the water conditions inside a modern washer. Insulated glass, a small water volume, pauses and the final rinse all affect what you feel. Touching the door at the end of a programme cannot establish whether the earlier wash reached its intended conditions.
A useful next step
Record the programme, displayed temperature setting and cleaning result. If a previously reliable heated programme now gives a changed result or a warning, discuss that specific pattern. Do not remove panels, put a hand into hot water or select an unnecessarily hot programme purely to test the heater; those actions add risk without establishing a dependable diagnosis.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.