Step 7 · Test the System

The final step is to confirm the problem is solved. Go to the appliance that was causing the issue—in this case, the washing machine. Start a wash cycle that uses both hot and cold water. Pay close attention during the fill cycle when the water valves will snap shut. The loud, sharp banging noise should be eliminated or significantly reduced to a very quiet thud. If the arrestors have worked, the hydraulic shock is now being absorbed by the air cushion within them. Your pipes are now protected from the damaging effects of water hammer.