How to Choose the Right Tub Filler

Whether it’s a soaking tub or a part-time shower, bathtubs get a lot of use. The bath is one of the first things noticed about the bathroom so the faucet and handles used on the tub are a good way to dress up the whole room. Here are a few tips to help you choose the perfect fixtures.

What Is a Tub Filler?

A tub filler is the larger type of faucet specifically designed for filling up a bathtub as quickly as possible. A bathtub can hold a lot of water, so if you try to draw a nice hot bath with a faucet that is too small, the water will cool before the tub is full enough to be enjoyed. A good tub filler can pour out as much per minute as the limitations of the water supply allows. When the average bathtub can hold somewhere between 30 and 80 gallons of water or more, that makes a big difference.

Can You Use A Sink Faucet Instead of A Bath Filler Faucet?

Illustration of tub filler and regular bathroom sink faucet.

When it comes to sink faucets and bath fillers, the two kinds of faucets are not interchangeable. While a kitchen or bathroom sink connects to a ⅜” water supply pipe, a bath filler faucet connects to the larger ½” pipe to allow more water flow. A bath faucet can fill a tub faster, using more efficient water pressure.

Bath Filler Flow Rates

Delta Floor Mounted Tub Filler for Free Standing Tub with Hand Shower

Choose a tub filler with the appropriate flow rate in Gallons Per Minute (GPM) for your existing plumbing

Kitchen and bathroom sinks often have flow restrictions that save money by saving water. This also saves on the energy required to heat up the water used for washing hands or rinsing the dishes. However, bath fillers dispense about the same amount of water with each use, and the goal is to fill the tub quickly, so in most cases, there are no aerators or flow restrictors.

Without flow restrictions, tub fillers are capable of moving anywhere between 1 and 20 (or more!) gallons of water per minute. It’s a good idea to match the faucet trim flow rate in — measured in Gallons Per Minute (GPM) — to the water supply pipe size capacity. Choose a ½” connection for a ½” pipe size, or a high flow, ¾” faucet to a matching ¾” pipe arrangement. The larger the tub size, the more efficient the higher GPM will be. Just make sure the pipe size and valves are compatible and comply with local codes.

Where To Install A Tub Filler

Jacuzzi Floor Mounted Tub Filler with Metal Lever Handle in brushed nickel.

Consider the bathroom layout. Moving plumbing will impact your remodeling budget.

Where the bathtub will be installed has a big impact on what kind of tub filler is possible. For instance, if your tub is surrounded by three walls (known as an alcove tub) you need to leave the fourth side open and unobstructed to get in and out of the tub safely. So, alcove tub faucets will be installed on the deck surround, or directly on one of the walls. A freestanding tub, however, is the perfect match for a freestanding tub filler as they can be installed wherever they fit — and look — best.

The existing water supply connections are a big factor in bathroom remodels. No matter what type of bath faucet you get for the tub, it has to be connected to the plumbing. It is easier to design around existing inlets and drains, rather than running new plumbing lines.

For many homes, it is usually possible to move and redirect the water supply lines to allow more design freedom with the tub layout. Redirecting pipes requires the work of a plumber or other contractors, to be sure everything is done properly and up to local building codes. Moving the plumbing will add to the cost of a bathroom remodel, and will also require extra time and scheduling, so be sure to plan your home improvement project accordingly.

A Note About Bath Faucet Placement

Moen Double Handle Low Arc Deck Mounted Roman Tub Filler, Rizon Collection

Place the tub filler for easy, unobstructed access to the bath.

The placement of the faucet will change how your bathtub looks, as well as how you use your tub. It’s important to choose a faucet that extends into the tub the right distance, and has controls that are easy to reach.

A few tips for faucet installation:

Make sure that the faucet spout you choose is the right size for your tub. The faucet spout is measured from the base of the faucet body to the middle of the spout’s water outlet.
The tub controls should be easy to access — both while sitting inside, and standing outside of the tub.
The faucet should be located 3” to 6” over the rim of the tub, and the controls should be at least 33” from the floor.
Mind the splash-zone. The higher the spout is over the rim of the tub, the more likely it is to splash water out of it.
If the tub is a freestanding, high-backed, slipper tub, the faucet should be placed along the lower end for the bather’s comfort, and to allow easy access into and out of the tub.
For slipper tubs with two reclining ends and a low middle, the faucet should be installed over the lowest point, along the side closest to the wall, to ensure unobstructed access in and out of the tub on one side.

Another consideration when choosing your bath faucet is the placement of the shower head. The shower fixture can be a handheld wand shower, or it can be an overhead shower, with options like a raincan faucet or a shower faucet with a customizable spray. Faucets with attached hand shower wands will have a cradle mount as part of their design, unless it is a wall-mounted shower connection. If you have a clawfoot or other freestanding bath and, look for shower conversion kits to safely hang shower curtains around the tub.

Freestanding Tub Fillers

Moen Doux Floor Mounted Tub Filler with Built-In Diverter in matte black

Freestanding tub fillers can be placed anywhere there's plumbing access for ultimate design flexibility.

Also called floor-mounted faucets, freestanding tub fillers allow design flexibility, because they are plumbed up through the floor, rather than through the wall. These faucets will work whether the tub is placed along a wall or in the middle of the room.

Freestanding tub fillers do require access to the underfloor of the bathroom, as the water supply lines must be routed to the tub’s location. Consult a contractor to determine if underfloor plumbing is possible in your home, particularly for bathrooms build on concrete slabs. In some cases, a raised platform can provide space to plumb a freestanding tub filler.

Wall-mounted Faucets

Pfister Tisbury Wall Mounted Tub Filler with Hand Shower, plished nickel

Wall-mounted tub faucets are available in shapes and finishes for every style.

Wall-mounted faucets connect to the water lines behind the wall, with no exposed pipes. They work well with freestanding tubs or alcove tubs, provided the tub is installed close to the wall on at least one side.

Wall-mounted faucets can be installed into the walls of the tub itself, into tiled walls, support walls, raised tub surrounds, shower enclosures, or short half-walls (called pony-walls.) The spout and handles take up the same space over the edge of the tub and should be installed 4” to 6” above the rim. For bathtubs tucked in alcoves, the controls can be off-set from center to ensure easy access from the outside of the tub as well as the inside. Wall-mount faucets often include hand showers, with cradles near the spout to keep the shower wand in easy reach. They can also be paired with shower kits and a separate shower head, such as a ceiling mounted raincan.

Deck-mounted Faucets

Delta Dryden Deck Mounted Roman Tub Filler Trim with Lever Handles

Deck-mounted faucets can be installed on a pony wall or specially designed tub.

Also known as roman tub fillers, deck mounted faucets are installed into the tub surround of drop-in or apron tubs. They can also be installed along the top edge of a short pony-wall on either end of the tub. If used with a platform or pony-wall, the plumbing may need underfloor access depending on where the tub is placed in the room. As with the freestanding and wall-mounted fillers, be sure to select a faucet with a long enough spout-reach to clear the distance over the tub rim.

Up on the deck, the tub spout, handshower, and temperature controls are arranged neatly within reach but out of the way. Deck-mounted faucets take up considerable width along the tub surround or supporting wall. They cannot be installed directly into the tub rim.

Clawfoot Tub Fillers

Pfister Savannah Double Handle Wall Mounted Clawfoot Tub Filler

Love the romantic look of a clawfoot tub? Choose the right faucet for your project.

Clawfoot tubs have been traditionally associated with Victorian design, but there are also updated contemporary versions. Though these clawfoot tubs are raised off the floor on four feet, they are, after all, just another variety of freestanding tub. In many cases, a clawfoot tub can use the same faucet options available for other freestanding tubs.

However, some clawfoot tubs have predrilled holes to accept a wall-mounted or rim-mounted faucet. These designs require the tub faucet to be installed directly onto the tub body, which means the water supply lines connect to the faucet after being directed through holes in the tub. Some clawfoot tubs have holes drilled into one end, on the vertical surface, to accept clawfoot-tub wall-mounted faucets. Others have holes drilled into the rim for special clawfoot-tub deck-mounted faucets.

Bath Filler Styles and Themes

Tub fillers can be an opportunity to add an interesting element to your bathroom design. Check out these popular styles:

Bathtub Faucet Valve Considerations

There are a variety of valve types working behind the scenes to make sure your bathtub faucets and shower heads do their jobs perfectly. Many brands require specific valves or rough-ins for their products, for instance switching an existing faucet to a Delta faucet will likely require a Delta-specific rough-in. It’s important to know the differences before you make your choice of bath fillers because there may be some extra installation work required if you choose to update to a valve-type other than what your bathroom is currently equipped for.

Valve Types

Moen Degree Diverter Valve Trim, Delta Innovations Three Function Diverter

Shower or Handle Diverter

The handle diverter is a part of the faucet trim but may require installation behind the wall, depending on if you have a wall-mounted faucet or a deck-mount. The handle diverter is a third handle knob or lever that stops water flowing to the bathtub spout and directs it instead to the hand shower wand or showerhead.

Spout Diverter

The spout diverter is installed on the bathtub spout. It is pulled up to direct water through the shower, or pushed down to direct water through the tub spout.

Thermostatic Temperature Valve

Thermostatic temperature valves use separate handles for water volume and water temperature. The temperature maximum can be set at the valve, or mixed via separate hot and cold trim handles, with only the water flow controlled by a third handle.

Pressure Balancing Valves

With a pressure balanced valve, the temperature and water flow are controlled using a single handle. The water can be set on the handle as hot as the water temperature in the water heater allows.

Anti-scald Valves

Anti-scald valves, also known as tempering valves, are used to prevent the water from going above a certain temperature. The device mixes cold water in to keep the hot water settings from climbing too high and to prevent quick fluctuation in temperature, which can cause scalding or thermal shock.

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