What F-20 / F-21 / F:20 (110 / Whirlpool-built Oasis and Elite) Means
On the Whirlpool-built Oasis and Elite dryers, F-20, F-21 and F:20 all report a failed heater relay on the main electronic control board. The relay is part of the board, which is why the published remedy names the board rather than a relay.
Common Causes of F-20 / F-21 / F:20 (110 / Whirlpool-built Oasis and Elite)
- A heater relay failed on the main electronic control board
- Surge damage to the relay drive circuit
- Years of heat cycling in an enclosed laundry space
🔧 One Safe Check You Can Try
Switch the dryer off at the breaker and leave it off; a heat-switching fault is not one to keep testing with another load.
⚠ Why You Shouldn't Go Further Than That
- A relay stuck closed can apply heat the control believes it has switched off, which is a fire-safety matter rather than a performance one.
- On gas models the supply is shut off at the appliance valve before any panel comes away; on electric models the breaker goes off first.
- Heat circuits on an electric dryer run at 240 volts, not the 120 volts most household wiring carries.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.