How To Connect Faucet Supply Lines? [Updated]

how to connect faucet supply lines

Once in awhile, all of us face a plumber situation. Either a faucet needs to change, leakage is happening, etc. But worry not; nowadays, faucet installation is becoming easier day by day.

In this article, we delve deep into how to connect faucet supply lines without any issues. In case you are thinking, “Well, I’ll just buy one of these faucets that are installable on top of the sink.” you will still need to know a few things before you begin your installation process.

how to connect faucet supply lines

So, How To Connect Faucet Supply Lines?

Turn Off The Water

Turn off the water at the shutoff valves under the sink or at the main water supply.


Remove The Old Faucet 

First thing first, you need to remove your old faucet before you begin installing the new one. This process should be pretty straightforward. The only issue you can face during this step is a stuck nut.


Usually, using a wrench should be enough to unscrew every nut and remove the old faucet from the sink. Even better than the old classic wrench is the basin wrench.


People tend to screw nuts way tighter than it is needed. In that case, wrenches won’t be able to do the job. To solve this without tiring yourself, you can wreck your old faucet a bit. You can use a rotary or oscillating tool to get rid of any stuck nut or any other part that doesn’t want to get removed.


Incorporate Silicone

Although not necessary per se, silicone is vital for the health of your sink and faucet. The water that gets underneath the faucet is likely to induce corrosion or damage your counter.


Usually, a newly bought faucet comes with a mechanical part that acts as a seal between the sink and the faucet. We advise you to use silicone on top of that seal, and the silicone will serve both as a leakage protector but also keep the faucet in place in case any nuts or screws get loose.


Get Your Supply Line Ready

  • Connectors

The faucet connection to the supply line has always been an essential part of the faucet installation process. If the connection is not made correctly, leakage is guaranteed.

There are two types of connectors you can use for the connection, modern and old school. Current connectors include a seal, as we mentioned before, but they cost more. On the other hand, old-school connectors are cheaper, but your tight cranking is mandatory for the nuts in this case.


  • Supply line length – Extensions

Although supply lines are often included along with a new faucet, their length might not be enough or include threads that won’t connect to the valves. To measure the length required for the supply lines, measure the distance from under the sink to the shutoff valves plus a few more centimeters.

After you took measurements if your supply lines are not long enough to buy extensions, also, to make sure the heads of the supply lines are the correct ones, they are compatible with the valves and bring the old supply line you removed when going to the store.


Faucet Attachment

In this step, you will attach the faucet. For firsts, the threaded tailpieces and supply connectors must be inserted in holes of the sink.


To ensure security for the faucet on the sink, you need to put a gasket and a nut on each threaded tailpiece you’ve set. Use a wrench to tighten the nut in place.


Next, you need to connect the supply lines to shutoff valves. Remember to join the red supply line for the hot water and blue supply line for the cold water to their respective shutoff valve.


Aerator Check

Aerators are devices that are connected at the end of the faucet. The purpose of the aerator is to mix air along with the water supplied to create a stream.


When you take the role of a plumber and mess with the sink, minerals, and waste that had been building up inside the valves, pipes and supply lines can be relocated, ending up getting the aerator clogged.


To make sure this doesn’t happen, you need to remove the aerator before turning the water on for the first time, for whatever built up is coming ends up in the sink. Then you can connect the aerator back to the faucet.

Aerators are pretty easy to remove, unscrew them.


Leakage Check

After we are done installing the faucet, we have to check if there is any leakage. This step is pretty straightforward, just turn one the water and have a look underneath the sink.


Bring along with you a few paper towels and wrap any connections with them. If there is any leakage, the paper towels will instantly get wet, and you will know the spot. Getting the leaking connection tighter will stop the leakage.


Instructions Safekeeping

If you did everything right, at this point, everything should be ready and working. Now, you have to pack all the necessary tools, spare parts, and instruction booklets in a plastic bag and put them in the cabinet underneath the sink.

This is done as a preparation for the next time you’ll have plumbing problems. Learning how to connect faucet supply lines can be challenging at first, but if you were to read it carefully we believe it is possible to make necessary improvements.

A Short Tutorial Video:


Having read this guide, you should know how to connect faucet supply lines and gaskets in your sink and do it easily.


It would be best if you remembered that whenever you have to do any plumbing task, get the right tools and spare parts to save yourself valuable time and irritations.


You also need to perform checks frequently. This is essential if you want to avoid any damage in your valves and pipes or even worse; the damage is done to your countertop, wall, and furniture because of any current leakage you are not aware of.


In a case like this, you will have to break part of the wall to swap the damaged part of the water supply or drainage pipes.


So, having said all that, remember to be better safe than sorry and keep sink safely.