Replacing a kitchen sink faucet is an easy task in many cases. The first consideration you should have is selection of your new faucet.
There are different grades available for your selection starting at inexpensive ones that essentially look good and work for a year or, two then you throw them away and get another, to mid priced ones that look better and work longer that repair well, and finally the higher end ones. You need to determine what meets your specific needs, as well as price range and style tastes.
The next thing that determines whether you can replace the existing faucet is the method used to connect the water supplies to your existing faucet. If the faucet has supply lines connected to a stop valve, that connect using a 3/8” compression connection, then run up to the faucet you should have no problems doing the work. If there is a rigid line that is soldered in place you may need a plumber unless you can sweat pipe.
You will need the new faucet, two-braided stainless steel faucet supply lines long enough to reach from the faucet to the stop valve connections, and possibly plumbers putty to seal the faucet to the sink deck depending on the faucet selected. For tools you will need an adjustable wrench, possibly a faucet wrench depending on access to the faucet mounting bolts, channel lock pliers, a bucket or other container to catch a small amount of spilling water, and something to clean the stain on the sink from the old faucet if the new faucet doesn’t cover the stain. Scotchbrite works well on stainless steel sinks.
Removing The Old Faucet
The first step is to shut off the water at the stop valves under the sink and turn on the faucet to make sure the water is indeed off. Then place the container under the stop valve to catch spilling water and remove the supply line from the stop valve connection with the adjustable wrench, then remove the supply line from the faucet connection. Once the supply lines have been removed you will need to unscrew the mounting nuts holding the faucet on. Many times I can reach and turn the nuts with the adjustable wrench or, channel locks, which I would use if I can, but sometimes there is too little space and a faucet wrench is needed.
Once the mounting nuts are removed lift the faucet up out of the holes in the deck and if there is a sprayer hose it can be disconnected up on top where it is easier in many cases. Once unscrewed the water can be drained into the container below by pressing the sprayer like you were spraying water and letting air in. Once drained the sprayer can be removed, then the sprayer mount is taken off by removing the mounting nut below just like the faucet mounting nuts.
With the faucet removed quickly clean the old plumbers putty out from where the old faucet was mounted and take the new faucet and hold it in place to see how well it covers the staining. This will show you the area of the sink that will have to be cleaned to remove the staining so it will not show once the new faucet is installed. Stainless steel sinks clean very well in most cases with Scotchbrite, other sinks can be tougher requiring repeated scrubbings with bleaching cleansers to remove the stain.
Installing The New Faucet
The first step is to look at the instructions that came with the faucet! Even I do that on every faucet I install. I have no way if knowing whether the manufacturer has made any design changes since the last time I installed the same faucet. Generally the faucet instructions will say how the faucet is sealed to the sink deck whether plumbers putty is used or, the faucet comes with a sealing gasket. If plumbers putty is used make certain that if the faucet is being mounted on a porous surface that you use Sta-Put Ultra Plumber Putty to avoid staining. Usually the first step is mounting the faucet to the sink deck and tightening it in place making sure that it tightens down in the correct spot. This will often entail checking several times when tightening. Then installing the sprayer and supplies, many of today’s faucets utilize quick connections that snap in place. Follow the instructions for your faucet! Make sure that the sprayer hose or, the hose to the faucet if you are installing a pull out faucet is routed so it will not tangle in the drainpipe or water supplies when you pull the sprayer or, pullout head out to use it. The quick connectors while very easy to connect are often much harder to disconnect.
Turning On The Water To The New Faucet
Turn on the faucet to the full cold position, then turn on the angle stop valve, and allow the water to run for a couple of minutes while watching for any leaks. Then repeat this step with the hot water. This step is important because many times debris can be dislodged and if you move the control on the faucet before it is allowed to flush with a full flow the debris can damage the new faucet. Sometimes the aerator on the faucet can become clogged with debris and you should remove the aerator to check for debris. The final step if you have a side sprayer is to run the water full hot making sure the water is good and hot then run the water through the side sprayer several times to get the coils to relax in the side sprayer hose then check to make sure it pulls out okay without getting tangled below and double check for any signs of leakage. Pay particularly close attention to the stop valves below. Frequently they will start leaking when used especially if they have been rarely used. Tightening the packing nut on them in many cases will stop the leaking.
Pick up the old faucet parts and tools clean up your work area and call it done.