A leaky kitchen pipe or foul-tasting tap water can ruin your morning fast. If you’ve chosen the AquaTru Under Sink RO System, you’ve already taken a major step toward cleaner, safer drinking water at home. This unit is built for straightforward DIY installation, requiring no professional plumbing experience. In this guide on how to install AquaTru under sink, you’ll learn every step from shutting off the water supply to flushing the system before first use. We’ll cover mounting components, connecting tubing, avoiding common mistakes, and ensuring a leak-free setup.
The process involves several critical phases: preparing your workspace, attaching the cold water adapter, mounting the drain saddle, installing the faucet, connecting the holding tank, and properly flushing the system. You’ll also get practical tips on avoiding overtightening, aligning connections, and verifying secure fittings. By the end, you’ll have full confidence in how to install AquaTru under sink safely and correctly the first time.
Prepare Workspace & Shut Off Water Supply
Before touching any tools, prepare your workspace and secure the water supply. A clear, dry area under the sink is essential for safe installation. Remove stored items, wipe down surfaces, and confirm you have enough room to maneuver. Verify that all components are present, including the filter manifold, faucet, drain saddle, holding tank, and both 1/2″ and 3/8″ cold water adapters.
Turn Off Cold Water Valve
Locate the cold water shut-off valve under the sink. Turn it clockwise until fully closed. Then, open the kitchen faucet to release pressure and drain residual water from the line. Continue running the tap until the flow stops completely. This prevents accidental spills and protects connections from pressurized flow during installation.
Confirm Safe Work Conditions
Briefly turn on the cold tap to verify no water comes out. Some sinks have separate lines for dishwashers or icemakers, so ensure you’ve shut off the correct valve. Once the line is depressurized, keep a towel nearby to catch minor drips and protect cabinet finishes.
Install the Cold Water Adapter
The cold water adapter connects your AquaTru system to the existing water supply. Choose the correct size, either 1/2″ or 3/8″, depending on your shut-off valve outlet. Both sizes are included for a proper fit.
Connect Tubing and Seal Threads
Attach the white inlet tubing to the tap water adapter. Wrap Teflon tape clockwise around the threads of both the shut-off valve and the adapter’s male end. This creates a watertight seal and prevents leaks. Hand-start the adapter onto the valve, then use an adjustable wrench to tighten gently.
Secure the Connection Without Overtightening
Connect the faucet connector hose to the adapter and tighten with the wrench, just enough to seal. Do not overtighten, as this can strip threads or crack fittings. The connection should feel firm but still allow minor adjustments when routing tubing later.
Mount the Drain Saddle
The drain saddle directs wastewater from the RO process into your sink’s drain pipe. It must be installed on a straight, accessible section of pipe, typically 1/2″ or 3/4″ in diameter.
Drill the Drain Hole
Mark the spot on the side of the drainpipe where you’ll install the saddle. Use a 1/4″ drill bit to bore a clean hole. Clear away any metal shavings to prevent clogs. Apply the included foam gasket inside the saddle to cushion the connection and reduce vibration noise.
Assemble and Tighten Saddle Evenly
Insert nuts into the recessed sides of the saddle half without foam. Align both halves over the drilled hole, placing the gasket between the saddle and pipe. Insert a 1/8″ drill bit through the saddle’s center to verify perfect alignment with the hole. Once aligned, secure the halves with bolts, tightening evenly on both sides to avoid warping the pipe.
Install the RO Faucet
The dedicated AquaTru faucet delivers purified water independently from your main tap. It requires a mounting hole, either existing or newly drilled.
Choose Faucet Location
Select a spot on the sink deck or backsplash within reach of the tubing. If drilling a new hole, use the appropriate bit for your sink material, since stainless steel, granite, or porcelain may require specialized bits. Drill slowly to avoid cracking the surface.
Mount and Secure Faucet
From beneath the sink, insert the faucet stem through the hole. Slide the plastic nut and included gasket onto the stem and hand-tighten from below. Ensure the faucet sits straight and doesn’t wobble. The decorative base should fully cover the hole for a clean finish.
Attach Quick Connect Fitting
Wrap Teflon tape around the faucet’s threaded outlet. Insert the clear washer into the Quick Connect fitting, then screw it onto the faucet stem. Hand-tighten with an adjustable wrench. Do not overtighten, as this can damage the seal and cause leaks.
Attach Holding Tank and Sanitizer
The holding tank stores purified water under pressure, ready for use. The TruePure sanitizer attaches directly to the tank and prevents microbial growth.
Remove Tank Cap and Install Sanitizer
Unscrew the blue cap from the top of the holding tank. Wrap Teflon tape around the stainless steel stem, then hand-tighten the TruePure sanitizer onto the tank. Use only hand force, since wrench tightening can damage internal seals.
Install Holding Tank Valve
Remove the black gasket from the sanitizer and place it into the RO holding tank valve. Wrap Teflon tape around the male threads of the sanitizer stem, then screw the tank valve onto the stem. Again, hand-tighten only. This valve controls water flow from the tank to the faucet.
Mount Filter Manifold and Insert Filters
The filter manifold supports the three-stage filtration system: pre-carbon, RO membrane, and post-carbon. Mounting it securely ensures stability and easy maintenance.
Choose Mounting Location
Select a wall or cabinet surface under the sink that can support the weight of the full system. Use the provided bracket and hardware to mount the manifold. Ensure it is level and accessible for future filter changes.
Install Filters in Correct Order
Insert each filter into its designated slot in the manifold. Note the color coding discrepancy between sources:
– Pre-carbon: Brown (most current) or Black
– RO membrane: White (most current) or Gray
– Post-carbon: Black (most current) or White
Refer to your unit’s labeling or manual to confirm correct placement. Filters can be temporarily removed to simplify tubing connections.
Connect All RO Tubing
Proper tubing routing ensures smooth water flow and prevents kinks or disconnections. Use the white and yellow tubes as specified in the connection diagram.
Cut and Prepare Tubing
Use a sharp utility knife to cut tubes to length based on your setup. Avoid crushing or bending the tubing. Cut ends should be clean and square for proper insertion into Quick Connect fittings.
Use Quick Connect Fittings Properly
Push each tube straight into its fitting until it seats at a depth of 5/8″. You should feel a click as the collet locks. Gently pull back to confirm it’s secure. Never angle the tube during insertion.
Follow the Connection Diagram
| Connection | Tubing Color | Route |
|---|---|---|
| Cold Supply | White | Water adapter to Cold Supply fitting (manifold) |
| Holding Tank | White | Tank valve to Holding Tank fitting (manifold) |
| RO Faucet | White | Water Faucet fitting to RO faucet Quick Connect |
| Drain Line | Yellow | Drain fitting to Drain saddle valve |
Route tubing neatly, avoiding sharp bends or pinching points.
Power Up and Flush the System
Once all connections are secure, it’s time to activate the system and prepare it for use.
Turn On Water Supply Slowly
Slowly open the cold water shut-off valve. This gradual pressurization prevents hydraulic shock. Check all connections immediately for leaks, especially at the water adapter, drain saddle, and faucet.
Open Valves and Fill Tank
Open the RO holding tank valve by turning the handle parallel to the outlet. The system will begin filling the tank, which takes 1 to 2 hours. It shuts off automatically when full.
Flush System Twice Before Use
Do not drink or use the first tank of water. Open the RO faucet and let the tank drain completely. Refill and drain a second time. This removes manufacturing residues, carbon fines, and ensures optimal water quality.
Final Leak Checks and System Readiness
After installation and flushing, perform a thorough inspection to ensure long-term reliability.
Inspect All Connections
Check every joint, valve, and fitting for dampness. Pay close attention to:
– Cold water adapter
– Drain saddle
– Faucet base and Quick Connect
– Holding tank valve
– Tubing connections
Retighten or reseat any leaking fittings. Replace washers if necessary.
Monitor During First Week
Check under the sink daily for the first week. Early leaks often appear after initial pressurization cycles. Address any issues immediately to prevent water damage.
Maintenance and Support Info
Keep your AquaTru system performing at its best with regular care and support.
Replace Filters Every 6–12 Months
Filter life depends on water quality and usage. Replace the pre-carbon, RO membrane, and post-carbon filters as recommended. Set calendar reminders to avoid lapses.
Sanitize System Periodically
Use manufacturer-recommended sanitizing procedures to prevent biofilm buildup and maintain peak efficiency.
Contact AquaTru Support
For help or replacement parts:
– Email: cs@aquatruwater.com
– Phone: 1-800-220-6570
– Hours: Mon–Fri 6:00 AM–4:00 PM PST, Sat 7:00 AM–3:00 PM PST
Download the full 8 MB owner’s manual from the AquaTru website for detailed specifications and safety guidelines.
Frequently Asked Questions About AquaTru Under Sink Installation
How long does it take to install AquaTru under sink?
The physical installation takes about 1–2 hours. However, the tank needs 1–2 hours to fill, and you must flush the system twice before drinking the water. Plan for a full afternoon to complete the entire process.
Do I need a plumber to install AquaTru?
No professional is required. The AquaTru system is designed for DIY installation using basic tools like an adjustable wrench, drill, and utility knife. If you’re comfortable with simple plumbing tasks, you can complete the setup yourself.
Can I install AquaTru without drilling a new faucet hole?
Yes, if your sink already has a spare hole or a soap dispenser you can replace. Otherwise, you’ll need to drill a new hole in the sink deck or backsplash using a bit appropriate for your sink material.
What should I do if connections leak after installation?
First, shut off the cold water supply. Check if the fitting needs slight retightening or if the Teflon tape was applied correctly. For Quick Connect fittings, ensure the tubing is fully inserted to the 5/8″ depth. Replace any damaged washers and retest.
How often should I replace filters in my AquaTru system?
Replace filters every 6–12 months depending on your water quality and usage. Heavy use or hard water may require more frequent changes. Set reminders to stay on schedule and maintain water quality.
Is the first tank of water from AquaTru safe to drink?
No. Do not drink the first two tanks of water. Flush the system twice to remove manufacturing residues, carbon fines, and any loose particles. After the second flush, the water is ready for safe consumption.
Key Takeaways for Installing Your AquaTru Under Sink System
Learning how to install AquaTru under sink is straightforward when you follow the sequence: prepare your workspace, shut off the water, install the cold water adapter, mount the drain saddle, attach the faucet, connect the sanitizer and holding tank, mount the filter manifold, route the tubing, and flush the system twice. The most common mistakes involve overtightening fittings and skipping the two flush cycles, both of which can cause leaks or poor water quality.
Your next step is to gather your tools, verify all components are present, and set aside a few hours for the installation. Once complete, you’ll enjoy clean, purified water straight from your tap for years to come. For ongoing maintenance, keep the 6–12 month filter schedule and contact AquaTru support if you encounter any issues.
