How to Replace a Toilet Supply Line

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This post covers how to replace a toilet supply line. Replacing your toilet connector at least every 10 years is a home maintenance item preventing water damage. This post covers how to do it along with what all you will need to make it as straightforward as possible. Included are additional tips that apply to every supply line replacement, making your next swap even easier!

We replaced our old toilet supply line with a Fluidmaster Click Seal Connector. I also cover the reasons why we chose this specific toilet connector. 

The rest of this post is mostly the script for the video. If you want to see how difficult (or easy) it is to do the replacement with these tools and materials, the video is the better way of viewing this post. However, for searchability and speed, this post is better for a refresher later.

TOOLS:

• tongue and groove pliers (ours expands to 1-¾”)
• old towel

MATERIALS:

If you need a compression shutoff connector:

• Fluidmaster Click Seal toilet connector (⅜” comp / ⅞” ballcock / 20 inch length) –it comes in 9”, 12” and 16” too
• to see it in-person or order & pickup at Home Depot

If you need the universal kit:

• Universal Fluidmaster Click Seal toilet connector (⅞” ballcock / 12 inch length)
• to see it in-person or order & pickup at Home Depot

During our last swap in location of our cloth diaper rinsing sprayer, the toilet connector at the toilet fill valve sprung a leak. So it was time to pull out tongue and groove pliers, and a towel. You could also use an adjustable wrench for the connector on the shutoff side. But if you don’t have one big enough, like this 200 mm one, and the fill valve side is stuck, you’ll still need tongue and groove pliers or something along those lines.

How to Replace a Toilet Supply Line

First, turn off the water at the shutoff to the toilet.

Then, lay the towel down below the supply line.

While a catch pan would be nice, it isn’t always the easiest to direct the water, at least with the auto-shutoff style toilet connector we’re replacing. A towel spread everywhere will catch all water trying to evade a catch pan.

Next, take off the old supply line. The fill valve side may be hand tight, but if it’s been on there a while or if there is any corrosion you may have to use more persuasion with tongue and groove pliers.

Then move on to the other side. It doesn’t really matter which side you do first. Ideally, it might be the shutoff side since it is lower and perhaps the water could be better guided out. Next time.

At this point, now that its off, either take a picture of the old tag or, better yet, bring it to the store.

Or have it right there by you if you order the replacement online. This way you know you have the correct connections on both ends and correct length.

I recommend buying a braided steel line for durability, leaving the leak potential for either end of the line and nowhere in between.

When we went to Home Depot to look at our options we ultimately ended up choosing a Fluidmaster ClickSeal supply line. For an additional dollar…

…it came with a 5 year warranty and, given our sprayer situation, the ClickSeal water connector would prevent us from over tightening the gasket once we remove the sprayer for the last time. Now that’s not to say that a 5 year warranty covers water damage, paying anyone to install it or anything above just getting a replacement supply line. But a boldly stated 5 years is more than a 1 year warranty–or no printed warranty on the tag–meaning Fluidmaster thinks their product will last longer. And for 6 bucks, skip a Starbucks in 5 years and buy a new supply line. I’ll tell you about what I’m doing with regards to preventing water damage towards the end of the post.

Now its time to reverse everything we just did taking it off. After you get the shutoff side hand tight, give it an extra quarter or half turn with the tongue and groove pliers. Just snug. Not too tight. The only difference is on the other side –there are no tools allowed! Just twist it in place until you hear the click. I will admit it was a little tough between the awkward position and attempting not to hit the phone on the tripod.

Once everything is connected it’s time to turn the water back on…and check for leaks. Even if there aren’t any, I’d leave the towel in place for a day. I specifically chose this one because its one of our grungy towels and, more importantly, if it gets wet you can see a change in color making a small leak fairly obvious and it’s definitely easier to see than a drop on the floor.

Here’s some additional installation tips:

The toilet tank only needs to be drained if the fill valve is replaced.

If you decide on a regular connection, rather than a click-seal connector, on the fill valve side of the supply line you’ll still want to only make it hand tight. Overtightening can cause the connection to fail. While ours was immediate, a failure may not be obvious for months or years down the road as pressure and thermal expansion stress the connection, which I explain in this video:

I recommend leaving the tag in place. It’s just so much easier having it in hand than going to the store or online in 10 years (pause) or 5 years and second guessing the connection. However, if you don’t know what you have, Fluidmaster also has a universal kit so you can modify the supply line connector to match with your shutoff valve.

It looks like they’ve updated the packaging, but I found an older one where you can see the ⅜”, 7/16” and ½” adaptors, which are now tucked inside the cardboard packaging.

Another reason to leave the tag intact is for warranty purposes. Some manufacturers require the tag to stay in place or it will void the warranty. While this Fluidmaster warranty requires a receipt or photo, keeping the tag in place is insurance if you misplace the receipt. If you have questions, definitely reach out to the manufacturer before choosing your new supply line. I called Fluidmaster customer service to get clarification on this issue and I was really impressed with no wait time and the knowledgeable and personable agent.

Now that we have the tag on the supply line, we have somewhere to write the date we installed it for record keeping.

You can also add a reminder 5 or 10 years down the road on your Google calendar to change your toilet connector.

If you are in the situation where you found this post as the result of a burst toilet supply hose, I’m in the middle of a video series on leak detection as well as series on water monitor and shutoff systems, which would detect even a small leak starting from failing supply lines. So definitely check those out (below) if you are looking to prevent water damage.

WATER METER LEAK DETECTION (you probably have this in your yard–so a free tool you already have):

This video explains how to use it:

This video explains how to locate a leak:

WATER PRESSURE GAUGE LEAK DETECTION (for $10-15 this is a SIGNIFICANTLY better leak detector):

How to use & locate a leak:

Which cheap water pressure gauge is best:

And making a water pressure gauge look cool:

THE REAL DEAL WITH 24/7/365 COVERAGE FROM A WATER MONITOR AND SHUTOFF SYSTEM: