Cleaning the Wet Lint Helped, but F9 E2 Returned in Three Days
On Whirlpool WHD560CHW2, compacted wet lint covered the heat-exchanger coils. The short callback showed that airflow cleaning had not closed the water-removal fault.
Why the first successful cycle was misleading
The dryer had once completed a full wet-load cycle during service, and the error then stayed away for roughly two and a half months. Intermittent operation therefore did not prove the system was clean or that condensate removal was reliable.
A similar symptom can have a different cause on another ventless dryer. Heat-exchanger blockage, drainage, a float signal, pump performance and controls can produce overlapping symptoms.
What the three-day callback proved
The technician found wet lint packed on the coils to about one centimeter in places and cleaned it thoroughly. F9 E2 returned three days later. That meant the contamination was genuine but insufficient as the complete explanation.
The next model-specific branch
The discussion then focused on condensate pump W11551760 and the float switch integrated with the pump assembly. The exact model and part were confirmed in the thread, but the pump had not yet been replaced and no final dry-cycle result was posted.