Step 8 · Restore Water and Test for Leaks
Ensure both connection nuts are snug. Very slowly, turn the shutoff valve handle counter-clockwise (to the left) to restore the water supply. Turning it on slowly prevents a sudden 'water hammer' surge of pressure. Once the valve is fully open, check both the upper and lower connections for any signs of water. Use a dry paper towel to wipe each connection; if the paper towel comes away wet, there is a leak. If you find a leak, turn the water off and try tightening the connection slightly (about 1/8 of a turn).