Cause of error code 23

24VAC voltage low/high

Sage2.1 control 24Vac control power is high or low.

Solution for error code 23

-Loose connection in 24Vac VAC power wiring.
-Loose or miswired 24Vac harness.
-Miswired wiring harness causing power supply short to ground.
-Defective transformer.
-Transformer frequency, voltage and VA do not meet specifications.