THIS PROCEDURE MUST BE PERFORMED BY A QUALIFIED TECHNICIAN.
THIS PROCEDURE MUST BE PERFORMED BY A QUALIFIED TECHNICIAN.
Error 20 occurs when there is a loss of communication from one circuit board to another. This may be caused by a loose connection of one of the interface cables, a defective interface cable, or a non-responsive circuit board. When troubleshooting, it is best to de-energize the Steffes heating system, disconnect and reconnect interface cables from the circuit boards one at a time, and then energize the heating system again. This will clear the Error 20 message if a loose connection was the cause. If the error message persists, examine the interface ports on each of the circuit boards for damage, corrosion, or debris. Verify the cable from the base I/O relay board is in the left port (Base I/O) on the LV expansion board. The time clock module, if installed, should be connected to the right port (TCM).