How to Install a Cup Washer on Your Kitchen Sink
Most plumbed sink-mounted cup washers install the same general way: through an existing or newly drilled hole in your countertop or sink deck, tied into your hot or cold water supply. Here's the process, plus where installs commonly go wrong.
To install a cup washer: (1) pick a mounting hole, since an existing soap dispenser hole works great, (2) feed the supply line down through the hole and connect it to your hot or cold water line with a tee adapter, (3) mount the base and tighten the retaining nut from underneath, (4) turn the water back on and test for leaks. Budget 20–45 minutes. If you'd rather skip plumbing entirely, a countertop model like the YBB Pitcher Rinser needs no installation at all.
Before you start: this is a broad-strokes overview of how sink-mounted cup washers typically install, not a substitute for the instructions that came in your product's box. Every sink and water line setup is a little different. Installation itself is fairly simple as plumbing projects go, but any DIY plumbing work carries some risk of leaks or water damage to cabinets, countertops, or flooring if a connection isn't sealed properly. Follow this guide at your own risk, and if anything about your setup looks unusual, call a licensed plumber instead.
What You'll Need
- An open hole in your countertop or sink deck (or willingness to drill one; check your sink/countertop material first)
- Access to the water shutoff valves under your sink
- An adjustable wrench and basin wrench
- Plumber's tape (PTFE tape) for threaded connections
- A tee adapter (included with most kits, including the Delta GR250-AR)
- A towel and bucket for the inevitable drips when disconnecting lines
Step-by-Step Install
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Turn off the water and choose your mounting hole
Shut off both hot and cold supply valves under the sink. Most cup washers mount in an existing unused hole, commonly a soap dispenser hole or a sprayer hole you're not using. If you don't have a spare hole, you'll need to drill one sized to the unit's base (check the product listing for the exact diameter before drilling).
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Feed the supply line through the hole
From above the sink, drop the unit's threaded shank and attached supply line down through the mounting hole so it hangs into the cabinet below.
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Connect to your water line with the tee adapter
Use the included tee adapter to tap into either your hot or cold line (your choice, though most people choose cold). Wrap threaded connections with plumber's tape before tightening, hand-tighten, then snug with a wrench; don't overtighten plastic fittings.
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Mount and secure the base
From underneath the sink, slide the mounting washer and nut onto the shank and tighten with a basin wrench until the unit sits flush and doesn't wobble on the countertop.
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Turn the water back on and test
Slowly reopen the shutoff valve(s). Press a cup onto the rinser and check every connection point below the sink for drips. Tighten anything that's weeping, then run it a few more times before calling it done.
Where installs usually leak: the tee adapter connection and the threaded shank under the sink. Both are worth a second check the day after install, once the fittings have settled.
Which of Our Picks Is Easiest to Install?
The Delta GR250-AR includes its supply line and tee adapter in the box, which keeps the install straightforward for a simple DIY replacement of a soap dispenser. The 2-in-1 Glass Rinser & Sprayer is a longer install (budget 20–30 minutes) since it's also acting as a sprayer. The seller includes a video walkthrough in the box, and we'd recommend watching it fully before starting. If you'd rather avoid plumbing entirely, the YBB Pitcher Rinser needs zero installation; just place it by the sink.
Install FAQ
How do you install a cup washer on a sink?
Most sink-mounted cup washers install through an existing or newly drilled hole in your countertop or sink deck, the same way a soap dispenser does: feed the supply line down through the hole, connect it to your hot or cold water line with the included tee adapter, and tighten the mounting nut from below. Countertop models like the YBB need no plumbing at all; just set them by the sink. See our full install guide for a step-by-step walkthrough.
Do glass rinsers make a mess?
They can if a cup isn't pressed firmly and squarely onto the nozzle, or if the unit is installed too far from the sink basin, water can splash outward instead of draining down. Models with tall side walls and a tilted base (like our budget pick) are built specifically to reduce splashing.
Do glass rinsers use hot or cold water?
It depends on the model. Plumbed sink units like the Delta GR250-AR connect to either your hot or cold supply line (your choice at install). Self-contained countertop units like the YBB rinser are cold-water only, since they don't tie into your home's water lines.
How do you clean a cup washer?
Wipe the basin and nozzle down with a damp cloth and mild soap weekly, and periodically remove any visible mineral buildup around the nozzle with a vinegar-soaked cloth if you have hard water. Most sink basins are stainless steel and can be cleaned the same way as the rest of your sink.