The moisture sensing circuit
F28 is about the part of the dryer that decides when a load is actually dry — the moisture sensing circuit — rather than a heating or airflow fault.
Deciding when the load is dry
Denton Repair Services' Whirlpool dryer code guide introduces it under the heating section: "F28 and similar codes on some platforms relate to the moisture sensing circuit, which decides when the load is dry." The phrasing "and similar codes on some platforms" is deliberate — like the thermistor group, the exact code name varies with the control platform.
What the code points at
The source keeps F28 short and does not give it a step-by-step fix of its own; its broader point is that "codes on these machines point at a circuit rather than a component." For a moisture-sensing fault, that means the sensor circuit — including the drum sensor bars and the wiring to the board — rather than a single part the code can name.
Non-official repair reference — this page summarizes a technician's guide; it is not a Whirlpool service manual.
Source and date
Source: Denton Repair Services — Whirlpool Dryer Error Codes · Checked 2026-11-12.