762 | C4 Electronic faucets · Installation M3-E Installation, use and maintenance 3. MAINTENANCE 3.1. TAP CLEANING neutral Hard soft Cl Clea n the tap using only non-acid liquid detergents. Do not use any kind of scouring pad. Keep windows clean, taking care not to scratch them. 3.2. CLEANING OF FILTERS Decalcify the aerator at intervals by placing the interior unit in vinegar. Clean the lters whenever any marked reduction of tap ow is noted.