Thank you for your question John.
In some cases simply replacing the batteries in the battery box for an electronic faucet solenoid may not reset the solenoid to a usable state. If this occurs, the solenoid will need to have some time without power connected to it for it to reset properly. It is best to get into the practice of removing the battery box from the battery wire, waiting a full minute or more, inserting brand new batteries into the battery box, and then reconnecting the battery box to the battery box wire. Allowing the full minute without the battery box connected will allow time for any remaining electricity in the solenoid to drain, essentially resetting it.
Best regards, Edward
Date published: 2017-09-03