Hans Grohe Metris 31100XX1 Installation Instructions Manual page 5

Cleaning:
Block the sensor for 5 seconds (1).
This will turn the water off for approximately 90 seconds,
so that the sink may be cleaned ().
Faucet Maintenance
Replace the battery
When the battery is low, the sensor will flash.
Remove the set screw from the back of the faucet (1).
Remove the handle screw and handle (model 31100
only) ().
Remove the faucet housing (3). Remove the old battery
(4). Install a new Lithium CR-P/6V battery (5).
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