Step-by-Step Guide: How to Install an Instant Hot and Cold Water Dispenser Under Your Sink
Updated: [2025-03-04] | Xiamen Smart Water Tech. Allen
Looking to upgrade your kitchen with instant hot and cold water at your fingertips? Installing an under-sink dispenser is easier than you think. This step-by-step guide walks you through the process, so you can DIY like a pro and enjoy endless convenience. Let's dive in!
What Is an Under-Sink Instant Hot and Cold Water Dispenser System?
An under-sink instant hot and cold water dispenser system is a compact, space-saving solution that provides on-demand hot and cold water directly from your kitchen sink. Unlike traditional countertop appliances (like electric kettles or water coolers), this system is installed discreetly under your sink, connecting to your existing plumbing and water boiler tank (for hot water models).
Key Components
Dispenser Faucet: A dedicated tap mounted on your sink or countertop, with separate controls for hot and cold water.
Water Heater Tank: A small tank (usually 2 L to 12 L) that heats and stores water at near-boiling temperatures (typically 45ºC- 98ºC).
Water chiller: For cold water, refrigerate the filtered water through a water chiller
Filtration: Many systems integrate filters to remove impurities, chlorine, or odors for better-tasting water.
Tubing & Valves: Connects the dispenser to your existing hot/cold water lines under the sink.
How Does It Work?
Hot Water: The heater tank maintains a steady supply of hot water, ready to dispense instantly. It refills and reheats automatically after use.
Cold Water: Pulls directly from your cold water line (or through a chiller if included).
Safety Features: Most hot water systems include child-safe locks, anti-scald technology, and automatic shut-off.
Top Benefits
Space-Saving: No bulky appliances cluttering your countertop.
Instant Convenience: Get boiling water for tea, coffee, or cooking in seconds-no waiting for a kettle.
Cost-Effective: Reduce energy use compared to reheating water repeatedly in a kettle or microwave.
Eco-Friendly: Eliminate single-use plastic bottles with filtered, on-tap water.
Versatile Use: Perfect for busy kitchens, offices, or homes with kids (e.g., quick baby bottles, oatmeal, or ramen).
Who Needs This System?
Homeowners tired of waiting for water to boil.
Tea/Coffee Enthusiasts who want precision temperatures.
Families looking for a safer, cleaner alternative to countertop appliances.
Small kitchens where counter space is limited.
How It Compares to Alternatives
| Feature | Under-Sink Dispenser | Electric Kettle | Countertop Water Cooler |
|---|---|---|---|
| Speed | Instant | 2–5 minutes | Instant (cold only) |
| Space | Hidden under sink | Takes counter space | Bulky |
| Upfront Cost | $500 | $100 | $300 |
| Long-Term Value | High | Low | Medium |
Why It's Worth the Investment
Saves Time: No more waiting for water to boil or cool.
Improves Workflow: Streamline cooking, baking, or meal prep.
Boosts Home Value: A modern, practical upgrade for kitchens.
Why Install an Under-Sink Water Dispenser?
Before we start, here's why this upgrade is worth it:
Save counter space: No bulky appliances.
Instant access: Boiling water for tea or cold water in seconds.
Cost-effective: Skip buying bottled water or electric kettles.
Tools & Materials You'll Need
Gather these supplies first (most come with the dispenser kit):
Instant hot/cold water dispenser unit
Dedicated faucet or dispenser tap
T-valve fittings (for cold and hot water lines)
Tubing cutter or sharp scissors
Adjustable wrench
Plumber's tape (Teflon tape)
Drill & hole saw (if modifying sink or countertop)
Bucket & towels (for spills)
Instant Hot and Cold Water Dispenser system installation diagram
Step 1: Turn Off Water Supply & Prep the Area
Shut off valves: Locate the cold and hot water valves under your sink and turn them clockwise to close.
Relieve pressure: Turn on the faucet above to drain remaining water.
Clear the cabinet: Remove cleaning supplies or items under the sink for workspace.
Step 2: Install the Dispenser Faucet
Most systems include a dedicated faucet. Here's how to mount it:
Drill a hole: Use a hole saw to create a 1.25" diameter hole in your sink or countertop.
Pro tip: Place the faucet near the existing sink faucet for convenience.
Insert the faucet: Secure it with the provided nut and washer underneath. Tighten with a wrench (don't overdo it!).
Step 3: Connect Water Lines
This is the heart of the system. Follow carefully:
Cold water connection:
Attach the T-valve to the cold water supply line under the sink.
Connect one end of the dispenser's tubing to the T-valve.
Hot water connection:
Repeat with the hot water line for systems with a heating tank.
Note: Hot water dispensers often require a dedicated electrical outlet for the heater.
Key tip: Wrap Teflon tape around all threaded connections to prevent leaks.
Step 4: Mount the Dispenser Unit
Position the unit: Place the hot water dispenser under the sink. Use brackets or screws if need mount on the wall.
Avoid kinks: Ensure tubing runs smoothly without sharp bends.
Step 5: Test for Leaks & Activate
Slowly turn water back on: Open the cold and hot water valves.
Check connections: Look for drips at T-valves, faucet, and tubing joints. Tighten if needed.
Flush the system: Let water run through the dispenser for 2-3 minutes to clear air and debris.
Test functions: Press the hot/cold buttons and confirm temperatures.
Common Mistakes to Avoid
Skipping Teflon tape: This causes slow leaks over time.
Overtightening fittings: It can crack plastic parts. Snug is enough!
Ignoring electrical needs: Hot water units need a GFCI outlet. Don't plug into an extension cord.
Maintenance Tips for Longevity
Replace filters every 6 months.
Drain and descale the hot water tank annually (check the manual).
Wipe the faucet regularly to prevent mineral buildup.
Final Thoughts
Installing an under-sink instant hot and cold water dispenser takes 1-2 hours but pays off daily. Whether you're a coffee lover, tea enthusiast, or just hate waiting for water to boil, this upgrade is a game-changer.
Need a reliable system? Check out our top-rated under-sink dispensers for hassle-free installation and durability.