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Replacing/Installing Faucets

How to install deck-mounted kitchen or bathroom faucets

ideaThere are many different faucet manufacturers who make many different styles of faucets, and installation techniques can vary from faucet model to faucet model. The information we're providing below is intended merely as a general guide for the most basic methods of installing faucets. Your particular faucet's installation process may differ, so please read the installation manual that (hopefully) was included with your faucet.

Also, if at all possible, we recommend wearing protective glasses when working beneath your sink, to block any debris from falling into your eyes.

General Information
A deck-mounted faucet is one that mounts on a horizontal surface, such as a sink or a countertop, as opposed to a "wall-mounted" faucet that mounts vertically on a wall or backsplash. Wall-mount kitchen or lavatory (bathroom sink) faucets are not as common, but are available. (The removal and installation information we'll be providing below will center on deck-mount faucets, not wall-mount faucets.)

Also, be sure to base your faucet selection on the options your sink provides. For instance, confirm the number of faucet holes that are drilled into your sink's rear faucet deck (or into your countertop, if your sink has no holes at all) and their center-to-center measurements before you purchase a new faucet.

When you purchase a new faucet, always keep your faucet literature somewhere safe in case you ever need it for reference in the future. Not only will it include installation instructions, but the manual also sometimes lists part numbers for repair parts and will also provide you with your faucet's model number (which most manufacturers or parts stores would need to be able to conduct any necessary research to assist you with a repair).

NOTE: If you are installing a new sink at the same time you're installing your faucet, it's usually easier to mount the faucet onto the sink before you install the actual sink itself.

Kitchen Sink And Faucet Info:
Some kitchens sinks have holes pre-drilled (or spots where holes can be drilled) for installation of a faucet, while other sinks have no faucet-holes at all. The more holes your kitchen sink has, the more options for accessories you will have; when your sink has no space for faucet holes, the faucet will either have to be installed on the countertop or on the wall.

When selecting a new kitchen faucet, make sure to take into account any accessories you currently have or are planning to install, such as a dishwasher air gap, a filter faucet, a soap dispenser, etc., as these items will also take up additional sink or countertop holes. For instance, if your kitchen sink has only four holes and one of them is being used for the dishwasher air gap, you should not purchase a faucet that requires a fourth hole for a side sprayer; there's no way, by Code, to eliminate an air gap if you have a dishwasher, so you would have no room to mount the sprayer. Note: dishwasher air gaps are necessary to prevent dirty water from backwashing into the dishwasher, which could then contaminate the fresh water.

The most common kitchen faucet designs require three sink holes; however, some may need as many as four or five holes (depending upon whether they come with a separate sprayer and/or another accessory, for instance), while other faucet models may use only one faucet hole. Kitchen sink holes are generally drilled four inches apart, when measured from the center of one hole to the center of the next hole; therefore, the holes that are drilled into a sink or countertop for a three-hole kitchen faucet would measure eight inches from the center of the left-hand faucet hole to the center of the right-hand faucet hole.

Lavatory Sink And Faucet Info:
Lavatory sinks, on the other hand, usually have three holes that measure either four inches apart or eight inches apart, from the center of each outer hole; these are known as either "four-inch center sinks" or "eight-inch-center" sinks. (The three holes in four-inch-center lavatory sinks would measure two inches from the center of the right-hand hole to the center of the middle hole, and two inches from the center of the middle hole to the center of the left-hand hole; the three holes in eight-inch-center lavatory sinks would measure four inches from the center of the right-hand hole to the center of the middle hole, and four inches from the center of the middle hole to the center of the left-hand hole.)

Be aware, too, that there are other sink designs that are not as common and may require special faucets or even separate hot and cold basin faucets Basin faucets are two separate faucet valves that don't mix the hot and cold water, but instead deliver hot water from one faucet tap and cold water from the other, separate faucet tap.

Four-inch centerset lavatory faucets are generally the most common bathroom faucet, and can be either the single-handle faucet style (single handle is manipulated to turn on the water flow and adjust its temperature) or the double-handle variety (Hot handle and the Cold handle are separate, and would both be used to initiate water flow and mix the water temperature). Four-inch-centered faucets are usually secured to the sink beneath each outermost faucet hole (with the center hole available for a pop-up sink drain's pull knob, if such a drain is being used); they most commonly consist of a single-pieced faucet body, but can instead be comprised of hot and cold handle controls and a spout in three separate pieces (which is known as a "mini-widespread faucet").

Eight-inch centerset lavatory faucets are referred to as widespread lavatory faucets, with separate Hot and Cold valves in the two outer holes and the spout installed in the center spot (where the pop-up knob would also protrude, if the faucet has that type of drain).

Removing Your Old Deck-Mount Lavatory Or Kitchen Faucet:
If you're replacing an old faucet, turn off the water supplies to the faucet first. Most installations will have a set of hot and cold shut-off valves (often called "angle stops" or "straight stops") beneath the sink, but you can shut off the water to the entire house if you aren't able to locate the faucet's individual shut-off valves.

Once you've shut off the water supply to the faucet, turn the handle(s) of your faucet to the "ON" position, so that the faucet's lines are drained and the pressure to the faucet has been relieved.

Beneath the sink, you'll see two supply lines leading up to the inlets of your faucet. (Sometimes the faucet's inlets will be very close to the underside of the sink's rim or the countertop; in other faucet models, you may see long copper tailpieces protruding down from the faucet, with the supply lines connected to the ends.) Use a wrench to disconnect the supply lines' nuts from the faucet inlets. It's also a good idea to have a towel or a small bucket available, as there will most likely still be water remaining in the lines that will drain out when you've disconnected them.

Once the supply lines have been disconnected, you'll need to remove the fastening mechanisms that are securing your faucet to your sink. This process varies widely, depending upon your faucet's design. You may find two large, 1/2" locknuts beneath your sink that are securing your faucet on each side (for which you can use something such as a "Basin Buddy" nut wrench or a "Quick Nutcracker" to loosen and/or remove), or you may have two simple screws extending down from each side with a bolt and a spacer plate securing the faucet to the sink. If you are removing a single-hole faucet, you'll usually find your mounting bolt beneath the faucet in the center. If the bolts or locknuts are not evident on the underside of your sink, examine the faucet components above the sink; sometimes (such as with some widespread lavatory faucets), you'll need to use a screwdriver or a hex wrench to remove the handles and decorative pieces to access the nuts that are securing the faucet to the sink.

If your kitchen faucet has a side sprayer, you'll have to disconnect it, as well. You'll usually find a hose-line beneath your sink that runs from the bottom of your sprayer to a small pipe nipple jutting from the underside of the faucet body; unscrew the nut on the end of the line from the pipe nipple, and then pull out the sprayer from above the sink. If your sprayer also had a decorative trim base, it can be usually be removed by loosening the nut that secures it to the sink (located beneath sink).

Some kitchen faucets have a sprayhead or handset that pulls out from the spout, with a long hose concealed beneath the sink. This hose type of hose will also connect to a pipe nipple on the underside of the faucet body, which you'll most likely need to unscrew before removing; note that the hose often also has a weight that's clamped onto it, which may need to be removed before you will be able to pull the hose through the body of the faucet. (Often, the weight is clamped onto the hose by two screws, which can be loosened to remove the weight.)

Once you are certain you've made all of the necessary disconnections, try to lift the faucet from your sink. If the faucet has a trim plate that's sticking to the sink, gently try prying the plate away from the sink with a flat instrument such a screwdriver or putty knife (being very careful not to damage the finish of the sink).

Clean away any extra putty, caulking, and/or debris from your sink's faucet installation area, so that it's ready for installation of the new faucet.

Installing Your New Deck-Mount Lavatory Or Kitchen Faucet:
If your faucet has a decorative deckplate (the type that spans all three faucet holes, whether on your kitchen sink or your lavatory sink), you'll need to make sure there's a watertight seal between the plate and your sink deck to prevent water from leaking beneath your cabinet. Most faucets usually come with a gasket of some sort to seal the deckplate against leaking; other faucet brands may not include such a gasket, which would then require you to seal the plate on the sink by using plumber's putty. (Some faucets include an extra "putty plate" for this very purpose, which would install beneath the decorative deckplate.) If the faucet you're installing does use a deckplate, position it over the sink's faucet holes you'll be using.

Some faucets don't use a deckplate; they may take up only one hole in your sink, or have components that each take up a separate sink hole with no plate between them. In such cases, make sure to seal beneath the trim ring for each component, using either the included gasket or plumber's putty.

Slide the faucet's piping through the appropriate holes in the sink (or your trim plate if you're using one, which you would've already placed on the sink).

From beneath your sink, you'll see the faucet's water inlets protruding down, along with the mounting bolts or nipples. Follow the instructions you received with your faucet to install the mounting nuts/washers/hardware (and to make sure you're installing all components, such as a side-sprayer, in the order that's specified), but be sure to tighten the hardware by hand only at first; that way, you can reposition the faucet from above the sink, to make sure it's straight, before you mount the faucet to the sink more securely. When you do use a wrench to tighten the hardware more securely, do not use excessive force or over-tighten, so that you don't damage the faucet.

If you've used plumber's putty to seal the deckplate, any excess putty will squish out when the faucet has been mounted completely. You can clean up this excess putty with a towel, or with a putty knife if necessary. One note about plumber's putty: It's a great sealant, but only when it's been exposed consistently to moisture; if the putty is allowed to dry out, it will crack and no longer prevent water from passing by.

It's now time to connect the water supply lines to your faucet's inlets. Be sure you are certain which is the Hot line and which is the Cold line, both in regards to the supply lines and the faucet inlets.

If you're using flexible stainless steel water supply lines -- which we highly recommend, due to their durability and ease of installation -- you shouldn't need to wrap the male threads on either the shut-off valve or the faucet line with thread-sealant tape. The rule of thumb when tightening a water flex line is: Hand-tighten, and then one-quarter turn with a wrench. (If you would feel more secure using thread-sealant tape as well, you can do so; however, be aware that too much thread tape can actually inhibit a successful seal, so make sure you only use a couple of wraps of tape, counter-clockwise.)

If you have the older, rigid style of water supply lines, which may even be connected directly to your shut-off valves, you might need to replace the cone washers in the ends of the lines (as the old ones may have deteriorated over time). Again, if at all possible, we would recommend replacing your old lines -- and the actual shut-off valves, too, if need be -- so that you can use the modern flexible stainless steel supply lines with separate shut-off valves; you won't regret it if you ever need to work on your faucet later down the line.

It's now time to test the faucet, for function and for leaks. Confirm the faucet is in the OFF position, and then turn on your water supplies. Carefully inspect the lines -- at the shut-off valves and at the faucet -- to see if there are any leaks. Look over everything closely for a few minutes, just in case any leaks are slow to develop. If you do see a leak, try to follow it to its source so that you can tighten or apply thread-sealant tape as necessary.

If you have no leaks underneath your sink, you can now turn on the faucet itself. Be aware that, because the lines are initially empty of any water, the faucet will have a tendency to sputter at first as it purges the air from its lines. This is normal, and will cease within a few minutes. Also, look under your sink again; check the lines, but also check the seal around the faucet's base plate to make certain it isn't allowing water to leak past.

Now, clean up the mess, and you should be ready to move onto your next task (whatever that may be)!

For consistent protection against leak damage, check your faucet periodically for leaks so that you can repair them before any costly damage occurs.