mypros+
Error code reference

Amana Dryer Error Code F:20

No voltage detected at the heater relay (appears ONLY in Diagnostic Test Mode).

Amana codesAmana dryer codes

No voltage detected at the heater relay (appears ONLY in Diagnostic Test Mode).

First step from the service manual

Check that the wires are plugged in on the heater assembly and at the relay on the electronic control.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

MyPros+ Max

Get the full diagnostic procedure for F:20.

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

What F:20 means on a Amana dryer

The F:20 error code on an Amana dryer indicates that the electronic control board has detected no voltage at the heater relay during Diagnostic Test Mode. This code is exclusive to the diagnostic cycle and will not appear during normal dryer operation. The heater relay is responsible for switching power to the heating element assembly, and when the control board polls that relay and receives no voltage signal, it logs the F:20 fault. This points to a break in the electrical circuit between the control board and the heater assembly.

The most common starting point for diagnosing this fault is the wiring. Loose, disconnected, or damaged wire harness connectors at the heater assembly itself or at the relay location on the electronic control board are frequent culprits. Vibration during operation can cause connectors to work loose over time, interrupting the voltage signal the board expects to see. Inspecting both connection points carefully before condemning any components is essential.

If the wiring connections are secure and intact, the fault likely lies with either the heater relay on the control board or the heater assembly itself. A failed relay may not close the circuit properly, preventing voltage from reaching the assembly. Similarly, an open circuit within the heater assembly could prevent the control from detecting the expected voltage. Systematic testing of the circuit from the control board through the wiring to the heater assembly is needed to isolate which component has failed.

Source: manufacturer service documentation.

Common causes of F:20

  1. 01

    Disconnected wiring at the heater assembly

    Wiring / connection

    The wire harness connector at the heater assembly may have worked loose or become unplugged. Visually inspect the connection point at the heater assembly and reseat any loose connectors.

  2. 02

    Disconnected wiring at the heater relay on the control board

    Wiring / connection

    The connector leading to the heater relay on the electronic control board can loosen over time. Check that all wires are fully seated at the relay terminal on the control board.

  3. 03

    Damaged or broken wire harness

    Part replacement

    The wiring between the control board and the heater assembly may have a broken, burned, or chafed wire that interrupts the voltage circuit. Inspect the full length of the harness for visible damage.

  4. 04

    Failed heater relay on the electronic control board

    Part replacement

    If the relay on the control board has failed internally, it will not switch voltage to the heater assembly. A faulty relay typically requires replacement of the control board.

  5. 05

    Faulty heater assembly

    Part replacement

    An open circuit within the heater assembly itself can prevent the control board from detecting voltage at that point in the circuit. Testing the heater assembly for continuity can confirm whether it is the source of the fault.

See the test procedure for each cause

Frequently asked questions about F:20

What does F:20 mean on a Amana dryer?
The F:20 code means the electronic control board detected no voltage at the heater relay during Diagnostic Test Mode. This code only appears when the dryer is run through its built-in diagnostic cycle, not during normal operation. It points to a problem in the circuit between the control board and the heating assembly, which could be a loose wire connection, damaged wiring, a failed relay, or a faulty heater assembly.
How do I fix the F:20 error code on my Amana dryer?
Start by checking that all wire connectors are fully plugged in at the heater assembly and at the heater relay on the electronic control board. Reseat any loose connectors and inspect the wiring for visible damage. If the connections are secure and the code persists in Diagnostic Test Mode, further testing of the heater assembly and the control board relay is needed to identify the failed component.
Will resetting my Amana dryer clear the F:20 code?
Because F:20 only appears during Diagnostic Test Mode, a reset may clear the display, but the underlying fault will remain. The next time the diagnostic cycle is run, the code will return if the wiring or component issue has not been resolved. Clearing the code without addressing the root cause will not restore proper heater function.
Is it safe to use my Amana dryer when the F:20 code appears?
The F:20 code appears only in Diagnostic Test Mode, so the dryer may still attempt to run normally. However, if the heater circuit has no voltage reaching the heating assembly, the dryer will not produce heat and clothing will not dry properly. It is best to diagnose and repair the fault before continuing regular use to avoid additional wear on components.
How much does it cost to repair an Amana dryer with an F:20 error code?
If the fix is simply reseating a loose wire connector, the repair can cost nothing beyond your time. If a wiring harness needs replacement, parts and labor can range from around $50 to $150. Replacing the electronic control board, if the relay has failed internally, is typically the most expensive repair, often ranging from $150 to $350 depending on the part and labor costs in your area.

Related Amana dryer codes

All Amana dryer codes
View all 38 Amana dryer codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass