How to Replace Your Toilet’s Water Supply Line

We go on a lot of water leak calls every week, and oftentimes, it isn’t very pretty.

All too often there’s a ton of water damage caused by a leak that was either too big or going for too long.

The water lines to your toilets are one common leak source to pay regular attention to.

We covered changing your washing machine water lines in last week’s email, now it’s time to look at those going to your toilet.

If you’ve been using a rubber supply line for your toilet, you may want to consider switching to a brass or braided steel line.

A line that matches the metallic color of your faucets will make your bathroom look a bit nicer.

And above that, it will be more dependable, last longer, and won’t be nearly as susceptible to cracks, breaks, and leaks.

You’ll especially want to consider this switch if you’ve been using the same rubber water line for several years, or if you’re already noticing wear and tear.

If your water line starts to leak, you’ll not only lose water, but you’ll run the risk of taking a nasty fall.

Replacing an old rubber water line with a metallic one can prevent these issues, and you can do it yourself in less than a half-hour.

How to Replace The Water Supply Line To Toilet

What you’ll need:

• A sponge
• A bucket
• A few towels
• Rubber gloves
• Channellock pliers

 Step One: Shut off the water supply to your toilet.

You can do this by turning the valve knob by the floor clockwise until you hear the water cut off.

You can also turn off the water for your entire home to be extra safe, but that isn’t often necessary.

Step Two: You need all the water in the back of the toilet to be gone.

Remove the cover from the toilet’s back and set it somewhere safe so it won’t get damaged.

Flush the toilet and hold the handle until you see all the water drain.

Then, put on your rubber gloves and use the sponge to soak up the remaining standing water.

Wring out the sponge in the bucket and repeat until the back of the toilet is relatively clear of standing water.

You can remove your gloves after this if you feel comfortable doing so.

Step Three: Lay down some towels just in case there’s any extra trapped water.

Use Channellock pliers to loosen the shut-off nut (the one just above the shut-off valve) and then remove it the rest of the way by hand. 

Step Four: Use the Channellock pliers to loosen the fill valve, which is the nut attaching the line to the back of the toilet.

Once it is loosened, unscrew it the rest of the way by hand as you did with the shut-off nut. 

Step Five: Both ends of the water line should pop off once the nuts are disconnected.

Beware of any trapped water.

Step Six: Attach the new line.

Start with the fill valve.

Line it up with the threads under the toilet’s back and screw it into place by hand.

Be careful not to over-tighten. 

Step Seven: Attach the shut-off nut.

Line it up where the old line was and turn the nut by hand clockwise.

You may want to finish tightening it with your Channellock pliers.

Be very careful not to over-tighten.

Note: If your new supply line is longer than the old one, it may curl in a loop. This shouldn’t be a concern as long as there are no kinks or bends.

Step Eight: Turn the water supply back on and replace the cover to the back of the toilet.

It may take a while for the back of the toilet to fill back up, so wait a while before you use it.

With a braided steel or brass water line, you can trust that your toilet can function without leaks.

That saves you the trouble of losing water and the risk of slipping on leaked water late at night!

May all your days be leak-free!

If you need professional help, see our services page on toilet repairs and installation or contact us today for an appointment or free quote.