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Install New Fill Valve — Install the New Supply Line

Beginner

Part of project

How to Replace a Toilet Water Supply Line · Step 3 of 4

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In this video

Insert the new fill valve through the hole in the bottom of the toilet tank, making sure the included rubber gasket is seated correctly. From underneath the tank, thread the new plastic mounting nut onto the valve's shank. Hand-tighten the nut securely, but do not use a wrench. Once the valve is secure, reattach the water supply line to the shank and hand-tighten it as well.

Goal: Secure the new fill valve in the toilet tank

  • Only hand-tighten the plastic nuts to avoid causing damage.

Used in this video

  • Tape Measure (Tool Type: Measuring Tools) · optional — Verifying the correct height positioning of the fill valve relative to the overflow pipe.
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FAQs

How difficult is it to replace a toilet supply line, and how long does it usually take for a beginner?

This is a beginner-level plumbing project, typically taking only 15-30 minutes to complete. The most time-consuming part is often ensuring all connections are leak-free. The cost is usually just for the new supply line, which is quite inexpensive.

Why is a braided stainless steel supply line recommended over other types, like plastic or standard polymer lines?

Braided stainless steel lines offer superior durability and burst resistance compared to older plastic or non-braided polymer lines. They are less prone to kinking and cracking over time, providing a more reliable and long-lasting connection to your toilet. This minimizes the risk of catastrophic water damage from a burst line.

What should I do if I find a leak after installing the new supply line and turning the water back on?

First, immediately turn off the water supply again at the shut-off valve. Gently tighten the connections a small amount (about a quarter turn) with your adjustable wrench. Ensure the rubber washers or cones are properly seated and not pinched. Avoid overtightening, as this can damage the fittings or line.

What if the water shut-off valve behind the toilet is old, stuck, or won't completely stop the water flow?

Do not force a stuck valve, as it could break and cause a larger leak. If the valve doesn't fully shut off the water, you'll need to turn off the main water supply to your house before proceeding. This might also be a good opportunity to replace the old shut-off valve itself, as a separate, slightly more involved project.

Transcript
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So back to the toilet, the new valve will go in the tank just like this, and it has to be positioned so that the water level line is a half inch below the top of the overflow pipe. So at this point you'll just have to make adjustments until you get it right. I'm sure there's a more elegant way to do this, but I just used the tape measure until I got it good enough for government work. The next step is to thread the mounting nut on the bottom of the fill valve. This should only be hand tightened. I also reconnected the supply line while I was down there.

Auto-generated transcript. May contain errors.