Step 7 · Connect New Plumbing Lines
From underneath, connect the new mixer hoses from the hot and cold handles to the corresponding inlets on the spout. Tighten these connections with an adjustable wrench, but do not overtighten. Next, attach the main hot and cold water supply lines to the inlets on the new faucet handles. It is highly recommended to use new flexible supply lines. If the threads are metal-on-metal without a rubber gasket, wrap them with 2-3 layers of Teflon tape in a clockwise direction before connecting. Tighten the coupling nuts until they are snug, plus an additional quarter-turn.