Continental Washer Error Code A-21

The A-21 code indicates a failure in inverter communication or an inverter parameter error, with the inverter itself displaying an internal fault code of Er3. The inverter is the component that controls motor speed, and this error means it has detected an operating condition outside its acceptable parameters or has lost communication with the main control board. The first step in diagnosis is verifying that the machine is correctly grounded, with resistance to a cold water pipe not exceeding 0.3 ohms.

A power reset may temporarily clear the A-21 code if the fault was caused by a transient event such as a brief power surge or signal interruption. However, if an underlying issue exists, such as a grounding problem, damaged wiring, or a failing inverter, the error will return once the machine resumes operation. Resetting without addressing the root cause is not a reliable fix.

Repair costs vary depending on the root cause. If the fix involves correcting a grounding connection or reseating a wiring harness, costs are minimal, mostly covering a service call fee in the range of 75 to 150 dollars. If the inverter module needs replacement, parts and labor combined typically range from 200 to 450 dollars or more, depending on part availability and local labor rates.

Some causes of A-21 are DIY-accessible, such as confirming proper grounding and inspecting wiring harness connections for loose or corroded pins. Grounding can be checked with a basic ohm meter by measuring from the machine chassis to a cold water pipe. However, if the inverter module or motor requires replacement, those repairs involve working near high-voltage components and are best handled by a qualified technician.

It is not recommended to continue using the washer while A-21 is active. The error indicates a problem with the inverter drive system, which controls the motor. Running the machine in this condition can potentially worsen the fault, cause damage to other components, or present an electrical safety risk, particularly if the grounding issue is the cause.