Thank you for your question. The light at the base of your Delta Addison Kitchen 9192T-AR-DST touch faucet, changes from blue, purple/magenta and red to indicate the temperature of the water. The light on the base also advises you when the batteries are going bad or have died.
Warning Mode-Replace batteries soon. Rather than the blue led, the red led will be illuminated when the water is on. When the water is off, the red led will flash once every 5 seconds.
Alert Mode-Battery Failure Imminent. The red led will flash once a second. the first time the faucet is used, the red led will turn on, the solenoid will be opened, and the manual valve must be used until the batteries are replaced.
Lockdown Mode-Replace Batteries.The red led is on and water will not flow until the batteries are replaced.
Date published: 2016-10-17