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Install New Fill Valve — Install New Supply Line

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How to Replace a Toilet's Flexible Water Supply Line · Step 5 of 6

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Install the new fill valve into the tank. Insert the new valve into the hole on the left side of the tank. From underneath, thread the plastic locknut onto the valve's shank and tighten it by hand. Make sure it is snug, but do not overtighten to avoid cracking the plastic or the porcelain tank.

Goal: Install fill valve

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FAQs

What specific type of new water supply line should I use, and what size do I need for my toilet?

You should use a braided stainless steel or polymer supply line for durability and burst protection; plastic ones can degrade. The most common size is 3/8 inch compression for the shut-off valve by 7/8 inch ballcock nut for the toilet tank, often 12-20 inches long depending on the distance between your valve and tank. Always measure your existing line or the distance to be sure.

What's the most critical first step to prevent a flood when starting this project?

The most critical first step is to completely shut off the water supply to the toilet. Locate the shut-off valve behind or near the base of the toilet and turn it clockwise until it stops. After shutting it off, flush the toilet to drain the tank and relieve pressure, ensuring no water will flow when you disconnect the old line.

How long does this toilet supply line replacement project typically take for a beginner, and what's its difficulty level?

This project is considered beginner-level and typically takes most DIYers only 15-30 minutes to complete. The most time-consuming part might be gathering your tools and preparing the work area. With the right tools and preparation, it's a quick and straightforward task.

What should I do if the new supply line leaks after I've installed it and turned the water back on?

If you notice a leak, immediately shut off the water supply to the toilet again. Check both connections to ensure they are hand-tightened, then use your adjustable wrench to give them an additional quarter to half-turn, being careful not to overtighten. Also, confirm the rubber washers are properly seated inside the nuts.

Install New Fill Valve — How to Replace a Toilet's Flexible Water Supply Line (Step 5, Video 3) | Stesso