The most expensive code
F01 is the code that can lead to the largest repair bill, so the source treats it with more caution than the others.
Main control board fault
Denton Repair Services' Whirlpool dryer code guide defines it as: "F01 generally indicates a main control board fault." It then adds a caveat most error-code pages leave out: "Treat this with healthy scepticism, since the board is the most expensive part in the machine and gets blamed more often than it fails."
Why to get a second opinion
The source's practical advice is to pause before paying: "A second opinion is reasonable before authorizing a board replacement." Because the code points at the board by default, the risk is replacing an expensive board when the real fault is a cheaper connection or sensor — so a confirmed diagnosis is worth more here than on a code like AF.
Non-official repair reference — this page is an independent summary of a technician's guide, not a Whirlpool service manual.
Source
Source: Denton Repair Services — Whirlpool Dryer Error Codes · Checked 2026-11-12.