How to Change a Toilet’s Water Supply Line

Changing your toilet’s water supply line is easier than ever. Gone are the rigid chrome tubes with compression fittings, unless you absolutely want to go that route. The simplest way is to use a braided stainless-steel flex tube. It doesn’t get much easier than this.

In offering these instructions, we’re assuming you’re only replacing the supply tube itself, and not the water supply valve.

Tools You Need to Change a Toilet Water Supply Line

• Bucket
• Bowl
• Towel
• Cup
• Crescent wrench
• New flexible stainless-steel supply line
  
  

Step-by-Step Guide for Changing a Toilet Water Supply Line

Ready to get started? Here’s how changing a toilet water supply line works.

Step 1: Get Your Measurements

1. Measure the distance between your water supply valve (on the wall or floor beneath the toilet) and the point where the line connects to the toilet tank. Allow an extra inch or two for slack.
2. Use your smartphone to take photos of your current water supply line in place, being careful to get both ends in the photo.
   
   

Step 2: Shut Off the Water

Turn off the water to the toilet by turning the supply valve clockwise.

If it’s a quarter-turn ball valve, it will only require a slight turn to stop the flow of water.

If it’s a gate valve, it will require several turns in the clockwise direction. If the valve is stuck, follow these instructions.

Step 3: Prepare the Bucket

Place a shallow bucket or bowl beneath each end of the water supply line to catch water that may come out when the line is removed.

Step 4: Take Off the Lid and Flush

1. Remove the toilet tank lid and place it in a safe place where it cannot fall or break.
2. Then flush the toilet until most of the water is gone from the toilet tank.
3. Use a cup to remove as much remaining water from the tank as possible.
4. You might even use a sponge to soak up residual water.
   
   

Step 5: Unscrew the Fittings

1. Use a crescent wrench or open-ended wrench to unscrew the fitting from the supply valve, turning it counterclockwise.
2. Repeat the task where the line connects to the toilet tank.
   
   

Step 6: Buy the Right Replacement

1. Take the existing toilet supply line with you to a hardware store or home center.
2. Choose a stainless-steel braided hose that is close in length. Note that it’s common for plumbers and homeowners to choose a longer line and install it with a gentle loop, so don’t worry if it’s longer than the original supply tube. 
3. Closely examine the ends to make sure they’re the same size as the ends on your old supply line.
   
   

Step 7: Connect the Parts

1. Connect the large end to the toilet tank’s fill valve nipple extending from the bottom of the tank. Hand-tighten the plastic nut and do not overtighten it, or you could break the porcelain tank.
2. Next, connect the small end to the nipple on the angle stop valve. Hand-tighten the nut, then use your wrench to tighten the connection just a bit more (never more than a quarter turn past hand tight).
   
   

Step 8: Test for Leaks

1. Turn on the water supply and check for leaks on either end of the line.
2. If you notice a drip, carefully tighten the nut at that end to seal the connection, being careful not to overtighten.
3. Then dry the tube, flush the toilet, and check again for leaks.
   
   

Get Help Changing a Toilet Water Supply Line

If this process sounds too tricky for your DIY skills, there’s no shame in throwing in the towel and calling in a professional. Not only will you get the peace of mind that the job was done right, but you’ll also get to avoid the stress and frustration of spending your Saturday tinkering on a project. Roto-Rooter plumbers are standing by 24/7/365 to help with any plumbing repair — toilet water supply line changes included.

Call our professionals now to schedule your appointment.

FAQs on Changing a Toilet Water Supply Line

Can I replace a toilet’s water supply line on my own?

Yes, swapping out a toilet’s water supply line is usually a simple+ DIY job. You’ll just need to be comfortable with a wrench.

What’s the process for changing a toilet’s water hose?

You just need to turn off the water, disconnect the old hose, then attach and tighten the new one.

What’s the typical cost to replace a toilet supply line?

Supply lines themselves don’t cost a lot, but you also need to consider the cost of all the tools and supplies you’ll need. In many cases, it’s cheaper (and more efficient) just to hire a plumber.

How often should a toilet’s water supply line be replaced?

The International Association of Certified Home Inspectors recommends replacing toilet tank components every five years, but you may need to do so sooner if there are leaks or visible wear.