Garbage Disposals, Water Filtration and Instant Hot Water

Everything on this page lives in the same place, the cabinet under the sink, and competes for the same space, the same drain and often the same receptacle. Choose the pieces together. The code points for disposals and drains are on our kitchen sinks, faucets and plumbing page. This page is about choosing the equipment.

Garbage disposals: continuous feed or batch feed

Motor size

Residential disposals are sold by horsepower, in fractional sizes up to about one horsepower. A larger motor is less likely to jam on fibrous or hard scraps and usually comes with a better grinding chamber. A small motor suits one or two people who scrape plates first. A household that cooks from scratch daily is better served by a mid-size or larger unit, which also takes more room under the sink.

Noise

The difference between a loud disposal and a quiet one is mostly insulation and mounting. Quieter models wrap the grinding chamber in sound-absorbing material, use a rubber-isolated mount so vibration does not pass into the sink, and have a baffle at the opening that holds sound in. The sink matters too. A thin stainless sink amplifies a disposal, and a heavy composite or cast iron sink deadens it. See kitchen sink materials.

Other things worth checking

• Grinding parts. Stainless steel components resist corrosion. Galvanized steel parts cost less and wear sooner.
• Jam clearing. Look for a manual release, usually a socket on the bottom for a small wrench, and a reset button you can reach.
• Height. The outlet has to sit above the drain in the wall. A deep sink plus a tall disposal can put it too low. See sink styles and configurations.

The switch

A continuous feed disposal needs a switch within reach of the sink. On a wall behind the sink that is simple. On an island there is no wall, which is where an air switch earns its place. It is a button set in the countertop or sink deck that sends a puff of air down a tube to a control box under the sink. No electricity reaches the button, so wet hands are not a concern. It needs its own hole, so tell the fabricator. The receptacle under the sink has requirements of its own, explained on the kitchen electrical code page.

Water filtration: choosing by what you want removed

Start with the problem, not the product. Read your water utility's annual quality report, and test your own tap if you are on a private well or have a specific concern. Our plumbing page linked above summarizes what the City of Vancouver's report says about hardness and PFAS. Then choose a system certified for that specific contaminant.

What the NSF/ANSI numbers mean

Filter packaging refers to NSF/ANSI standards. NSF, the organization that develops and certifies to them, describes them this way:

• NSF/ANSI 42 covers aesthetic effects, meaning contaminants that are not health-related. Claims include chlorine, taste and odor, chloramine and particulates.
• NSF/ANSI 53 covers health effects. It offers more than 50 contaminant reduction claims, among them lead, Cryptosporidium, volatile organic compounds and chromium.
• NSF/ANSI 58 is the standard for point-of-use reverse osmosis systems. It covers total dissolved solids reduction, efficiency and recovery ratings, and other contaminant reduction claims.
• NSF/ANSI 401 covers emerging contaminants, up to 15 specific compounds that have been found in drinking water at trace levels.

Two cautions. First, a standard number alone tells you very little, because certification is claim by claim. A filter certified to NSF/ANSI 53 for one contaminant is not certified for the other claims in that standard. NSF itself says certification does not mean a system will reduce all possible contaminants. Second, "tested to" or "meets" a standard is a manufacturer's statement, while "certified" means a third party verified it. Look up the exact model in the certifier's public listing and read the list of claims. PFAS reduction, if that is your concern, is a specific claim made under NSF/ANSI 53 or 58, so confirm it appears on the listing.

Reverse osmosis practicalities

• It needs a connection to the sink drain as well as to the cold supply, and how that connection is made is a plumbing code matter.
• A conventional system stores treated water in a pressure tank. Tankless systems save space and need power.
• It normally feeds its own small tap, which needs a hole in the counter. Coordinate that with your faucet choice.

Instant hot and chilled water taps

An instant hot dispenser is a small insulated tank under the sink that keeps water near boiling and delivers it from its own tap. It suits people who make tea, pour-over coffee or instant meals many times a day, and it speeds up starting a pot of pasta.

• It needs power. The tank plugs into a receptacle in the sink base. If a disposal is there too, tell your electrician early so the wiring is planned for both. That is a question for the electrician and the electrical permit, not something to work out at installation.
• It needs space and air. The tank is warm and should not be packed tightly among stored items.
• It is hot enough to scald. Choose a tap with a safety lever or a two-step action if children use the kitchen.

The space all of it needs

A standard sink base holds less than people expect once the sink bowl, the trap and the supply valves are in it. Add these and count:

• Disposal, and its air switch control box if used
• Dishwasher drain hose and air gap tubing
• Pull-down faucet hose and weight, which need a clear path to swing
• Filter cartridges, with clearance below them to unscrew the housings
• RO storage tank
• Instant hot tank
• On an island, the loop vent rising inside the cabinet

Ways to make it fit: choose a sink with a rear drain, use a compact disposal, go tankless on the RO, move the waste pull-out to the neighboring cabinet, or use a wider sink base. Draw it before buying. Storage planning for the rest of the kitchen is in kitchen storage and pantries.

What to check before you buy

1. Disposal: feed type, motor size for how you cook, sound insulation, stainless grinding parts, overall height and mount type.
2. Sewer or septic. If septic, get advice before adding a disposal.
3. Filter: the contaminant you are targeting, and the certified listing for that exact model and claim.
4. Counter holes: air switch, filtered tap, instant hot tap, air gap, soap dispenser.
5. Power: what needs a receptacle under the sink, agreed with the electrician.
6. A scale drawing of the sink base with every item in it.

Who should choose which

• On city sewer, cooking daily: a mid-size or larger continuous feed disposal with good insulation.
• Small children in the house: a batch feed disposal, or none.
• On a septic system: no disposal, or very light use with advice from your septic provider.
• You want better-tasting water: an under-sink carbon filter certified to NSF/ANSI 42 for taste and chlorine.
• You have a specific health-related concern: a system certified for that contaminant under NSF/ANSI 53 or 58, verified in the listing.

Adding a disposal, a filter line or a new drain connection can bring plumbing and electrical permits into the job. Our permit guide explains when. JDI Construction lays out the sink base on paper with you before rough-in, so every tank, hose and receptacle has a place. To plan yours, start at kitchen remodeling in Vancouver.