Home repairs are hard enough, even with all the how to videos online today. These videos often overlook how to buy the right materials for the repairs they're illustrating. So it's not surprising when I talk to women shopping solo at Home Depot or Lowe's, they aren't sure about what they need to buy (supply lines aren't always grouped according to fixture). So when we had a toilet leak recently, it was time to take photos and explain what you need to know when shopping for supply lines for any type of plumbing repair in your home.
What are Supply Lines?
What are Supply Lines?Our houses are like magic when we turn the faucet on, water comes out … and with a small hand lever, we can flush our toilets. Fresh and waste water mysteriously arrives where it's needed through a serious of plumbing pipes from your well or city water supply, to each fixture in your home that uses water. Water supply lines are used to move fresh water from the pipes inside your walls, to each of these fixtures.
Where water leaves the wall to fill a toilet bowl, there's a shutoff valve. This is needed to drain the toilet for repairs or replacing the toilet. The supply line is a flexible tube that extends from the shutoff valve to the fill valve that sits at the bottom of the toilet bowl.
How to Shop for Supply Lines
How to Shop for Supply LinesA word of caution about the table below. There are industry standards but they change over the years as building codes change. The most important reason for including the table below is to highlight the different fill valve and shut off valve diameters. You wouldn't be happy returning home with supply lines that are the right length but intended for a faucet when you're fixing a toilet, or vice versa. At the same time we strongly encourage you to measure because there are exceptions to everything.
Note: In researching the data for the table below, I saw many online supply lines that lacked a label for toilet versus faucet … so shop with care.
| Fixtures with Supply Lines | Fill Valve | Shutoff Valve | Length |
| Faucets | 1/2 in | 3/8 in | 12 to 96 in |
| Toilets | 7/8 in | 3/8 in | 9 to 20 in |
| Showers/Bathtubs | fixed plumbing inside walls | ||
| Dishwashers | 3/8 in | 3/8 in | 60 to 96 in |
| Washing Machines | 3/4 in | 3/4 in | 60 to 72 in |
| Refrigerator & Filter Lines | 3/4 in | 24 to 120 in | |
What Supply Lines Look Like Online
You might find buying supply lines less intimidating online. Neither is easy as you'll have multiple choices, but online you can research each product and check customer feedback. Alternatively you'll often find yourself in an emergency situation like we had on Thursday night, where you can shut off the water to a toilet (as long as you've got more than one) and wait … or head to the store.
Faucet Connectors 24″ (Hot & Cold)
Stainless Toilet 6″ Supply LineDishwasher Supply LineStainless Ice Maker Line
&
*Note: While the most common size for shutoff valves is 3/8 in, when uncertain, buy a universal supply line which has a 1/2 in iron pipe size for very old valves and bushings for 1/2 and 3/8 compression.
My husband wants to fix our bathroom and he needs some plumbing supplies. I like that you recommend measuring the lines that you will be replacing before you head to the store. I will definitely make sure that we follow your advice before we do anything else.
Yes, you want to minimize # trips and measuring or taking things with you can usually do this.
I’m glad you pointed out that buying plumbing supply lines online can be less intimidating, since we’ll have all the time we need to research each product and check its customer feedback. I’ve been having some plumbing trouble in my home and have determined that a supply line needs to be replaced, but I’ve been having trouble choosing one to purchase. I’ll definitely take your advice and shop around online to take some of the pressure off!
I didn’t know that the supply line is a flexible tube that extends from the shutoff valve to the fill valve that sits at the bottom of the toilet bowl. Our toilet bowl is not flushing and we don’t know what to do. My dad suggested having contractors prepare for plumbing supplies and shared this article with us.
Thanks for the information, especially about plumbing supply lines and how they get fresh water where it’s supposed to be. A toilet in my house started leaking recently, and I have been trying to figure out how to fix it. Hopefully the issue will turn out to be with the clean water supply lines.
Luke, You can do better than this comment as you are a plumber! How about sharing something valuable for homeowners, like the top 3 problems we don’t have to call a plumber for?
You mentioned that water supply lines are used to move fresh water from the pipes inside your walls to each of these fixtures. Do most plumbers prefer certain types or brands of pipes? When my wife and I came home from vacation we found that our bathroom had flooded. Hiring a plumber to come and check our supply lines might be a good idea.
I really like the suggestion to make sure you measure old supply lines before you go out shopping for new ones. I can’t tell you the number of times I’ve forgotten to measure and ended up not being able to buy the right size. Even with the industry standards, its good to check and make sure, like you said. I appreciated the great reminder, so thanks for sharing!
Thanks Tobias, as we tend to overlook information we’re not familiar with & in this case, it does make a difference.