A. O. Smith AOS-HERO-CHR High-Efficiency Reverse Osmosis System Owner's Manual and Installation Guide

Welcome & Product Overview

Congratulations on your purchase of the A. O. Smith High-Efficiency Reverse Osmosis system with SmartFlow™ technology. This system is designed to provide you with optimally clean water, reducing up to 99% of harmful contaminants. It offers more pure water, less water waste, and longer filter life compared to average reverse osmosis systems.

Keep this manual for installation, troubleshooting, and filter replacement information. For assistance, please call 877.333.7108.

Filter Replacement Frequency:

Carbon Blocks (Stage 1 & 3): Every 6 months
SmartFlow™ Membrane (Stage 2): Every 12 months

Use only certified, genuine A. O. Smith replacement filters for optimal performance. Find replacements at aosmithatlowes.com or your local Lowe's store.

Box Contents

The following parts are included in your system:

A SYSTEM MANIFOLD
B STAGE 1: CARBON BLOCK
C STAGE 2: SMARTFLOW™ MEMBRANE
D STAGE 3: ADVANCED CARBON BLOCK
E AIRGAP FAUCET WITH PRE-CONNECTED TUBING
F SLOTTED FAUCET WASHER
G WATER TANK AND STAND
H EYEDROPPER
I DRAIN SADDLE KIT
J TUBING 1/4" WHITE
K TUBING 1/4" YELLOW
L INLET TEE VALVE
M WATER TANK VALVE

Please read the entire manual before installation to ensure all parts are present. If any part is missing or damaged, call 877.333.7108. Do not attempt installation if parts are missing or damaged.

Recommended Tools for Installation:

? Tape measure
? Plumber's tape
? Phillips head screwdriver
?️ Drill with 7/16" bit
? Adjustable wrench
? Bleach
? Safety glasses
✏️ Pencil
?️ Pan or bucket
? Utility knife

Note: Professional installation is recommended for pipe cutting or drilling. Basic plumbing knowledge is advised.

Installation Guide

STEP 1: Site Setup

This system requires a faucet hole between 1" and 1 1/2" in diameter in your sink or countertop for the dedicated faucet. You can also use an existing kitchen sink sprayer, soap dispenser, or pre-existing hole.

If drilling a new hole, ensure the faucet body mounts flush and there's sufficient tubing between the faucet and manifold. Professional assistance and safety glasses are recommended for drilling.

Unpack and unwrap contents.
Turn off the COLD water supply. Open the kitchen faucet to release pressure and drain the line.
Temporarily place the system manifold and water tank under the sink or in the desired location to ensure adequate space and proper positioning.
Measure blue and red tubing from the faucet hole to the system manifold, and yellow tubing from the water tank to the manifold. Ensure tubing lengths are sufficient. Do not cut tubing until instructed.
Remove the system manifold and water tank from under the sink to begin installation.

System Dimensions:

Water Tank: 13.74" (34.9 cm) height, 9.06" (23 cm) diameter.
System Manifold: 12.93" (33 cm) height, 4.5" (11.5 cm) width.

STEP 2: Install Air Gap Faucet

Feed the pre-connected air gap faucet through the countertop hole.
Under the countertop, slide the slotted faucet washer onto the faucet's threaded base, between the countertop and the white plastic spacer. Adjust the nut if needed to create space for the washer.
Tighten the nut with an adjustable wrench, but do not overtighten.

STEP 3: Install Drain Saddle

⚠️ WARNING: Ensure all electrical appliances are turned off at the circuit breaker before proceeding. Wear safety glasses.

Identify the drain outlet location on the drainpipe for the drain clamp. Do not install on the same pipe as a garbage disposal. Mount the clamp as low as possible on the vertical or horizontal drainpipe tailpiece.
Using the drain connector hole as a template, drill a 7/16" hole into the drainpipe, drilling only through one side.
Attach the foam gasket to the drain clamp half. Remove the center hole and protective cover from the gasket's back. Align the gasket hole with the clamp's internal hole. The adhesive side of the gasket should face the inside of the clamp. Press firmly to attach.
Insert nuts into the other half of the drain clamp. Align both halves around the drainpipe over the drilled hole. Use the drill bit to help align.
Tighten nuts and screws with a screwdriver to secure the drain clamp. Do not overtighten.

STEP 4: Install Inlet Tee Valve and Tubing

Note: Ensure the water valve is turned off before continuing.

Place a pan or bucket under the cold water line to catch excess water. Disconnect the COLD water line from the supply shut-off valve using an adjustable wrench.
Attach the threaded ends of the inlet tee valve to the COLD water line at the shut-off valve. Tighten with a wrench, but do not overtighten.
Reconnect the cold water line to the top of the tee valve.
Push the white tubing into the open quick connect valve. Ensure the inlet tee valve is in the open position.

STEP 5: Install System Manifold

Place the system manifold under the sink in an easily accessible location for future filter changes. Do not install filter cartridges at this time.

STEP 6: Sanitize and Install Water Tank Valve

Using the included eyedropper, add 3ml of bleach into the top of the water tank.
From the accessories box, find the water tank valve.
Screw the water tank valve onto the stainless-steel connector on top of the tank. The valve is pre-wrapped with plumber's tape to help seal threads and prevent leaks.
Hand tighten the valve until secure, ensuring not to cross-thread or overtighten. After hand tightening, use a wrench to tighten a quarter turn for a secure fit.

STEP 7: Connect Water Tank to System Manifold

Open the water tank valve, ensuring it points towards the valve port.
Insert one end of the yellow tubing into the water tank valve.
Place the water tank on its stand near the system manifold.
Connect the water tank to the system manifold by connecting the other end of the yellow tubing to the yellow inlet port on the back of the manifold, labeled 'tank'.

STEP 8: Connect Tubings

Notes: Ensure tubing is fully inserted for a secure connection (up to 1 inch). Wetting the tubing end can ease insertion. Avoid bending, kinking, or crimping tubing, as this affects performance. If tubing is too long, measure and cut straight across, not at an angle.

Faucet Connect:

Connect the pre-installed 1/4" red tubing (smaller) from the faucet to the system manifold's red inlet port, labeled 'waste'.
Connect the pre-installed 1/4" blue tubing from the faucet to the system manifold's blue inlet port, labeled 'pure'.
Connect the pre-installed 3/8" red tubing (larger) from the faucet to the open port of the drain saddle. Ensure the tubing does not dip below the drain saddle.

Inlet Tee Valve Connect:

Locate the white tubing connected to the inlet tee valve. Cut the white tubing to the necessary length to reach the back of the system manifold.
Push the white tubing into the white inlet port on the back of the system manifold, labeled 'inlet'.

STEP 9: Insert Filter Cartridges

Insert each filter cartridge into its designated location in the system manifold by turning it to the right. Ensure the filter handle is vertical to the manifold before inserting. Guides on each filter ensure proper alignment.
Once engaged, push the filter fully in while rotating 90 degrees to the right. Repeat for all filters.

Filter Types:

Top filter: Carbon Block
Middle filter: SmartFlow™ Membrane
Bottom filter: Advanced Carbon Block

STEP 10: Pressure Test, Check for Leaks, and Flush

Close the dedicated faucet.
Turn on the COLD water supply valve.
Open the kitchen faucet to release air from the pipes. Once water flows normally, close the kitchen faucet.
Pressure will build in the system within approximately two hours. During this time, carefully inspect all connections and fittings for leaks.
After confirming all connections are secure, open the dedicated faucet. Let the water flush for two hours.

Note: Initial flush water flow may be slow, and bubbling noises are normal. Do not drink the flushed water.

Once flushing is complete, close the dedicated faucet.

Note: After the initial flush, the water tank will take 1-3 hours to fill.

Care and Safeguards

Care

To clean the system manifold and tank, wipe the exterior with a damp cloth. Do not use abrasive cleaners or solvents.

Safeguards

If a tubing connection leaks, shut off the cold water, disconnect, and re-seat the tube.
Do not install where line pressure may exceed 100 psi (689.5 kPa). The operating range is 40-100 psi (275.8-551.6 kPa).
Install only on COLD water lines (40°F-90°F / 4.44°C-32.22°C).
Install indoors, away from direct sunlight and freezing temperatures.
Ensure system and installation comply with applicable state and local laws.
Do not operate without filters installed.
Do not use with water that is microbiologically unsafe or of unknown quality without adequate disinfection.
Systems certified for cyst reduction can be used on disinfected waters with filterable cysts.
This RO system contains replaceable components critical for contaminant reduction. Periodically test the system to ensure proper performance.
Replace components with identical specifications from the manufacturer to maintain efficiency and contaminant reduction performance.

Specifications

Efficiency Rating: Percentage of influent water available as treated water under typical daily usage conditions. Verified per NSF/ANSI 58, Section 6.8.

Recovery Rating: Percentage of influent water available to the membrane when the system operates without a tank or with the tank bypassed. Verified per NSF/ANSI 58, Section 6.8.

Performance depends on pressure, temperature, and Total Dissolved Solids (TDS).

Lower temperatures result in slower flow rates.
Do not install in areas prone to freezing.
Incoming water temperature should not exceed 90°F (32°C).
Higher incoming TDS requires more filter time. Incoming TDS should not exceed 1000 ppm.
Higher water pressure allows for a higher flow rate. Pressure must be above 40 psi (276 kPa) for proper operation. Consider a booster pump if pressure is below 40 psi.

Flow rate and output are determined by:

Incoming water temperature
Total dissolved solids (TDS) in supply water
Incoming water pressure
Tank size and water amount

Model	Replacement Cartridge	Operating Temp. Range	Recovery Rating	Efficiency Rating	Daily Production (DPR)
AOS-HERO-CHR	AOS-HERO-S1S3, AOS-HERO-S2	40-100°F (4-37°C)	42.8%	27.4%	25.7 gpd (97.3 lpd)

Manufactured by: A. O. Smith Corporation, 11270 W Park Pl #170, Milwaukee, WI 53224 | 877.333.7108

System tested and certified by WQA to NSF/ANSI Standards 42, 53, 58, and 401. Conforms to NSF/ANSI 53 for VOC reduction. All claims verified by test data.

Scan the QR code for the full list of filtered contaminants and the AOS-HERO-CHR Performance Data Sheet.

Filter Replacement Schedule

Carbon Block and Advanced Carbon Block (Stages 1 & 3): Replace every 6 months*. May require more frequent replacement with high water usage or sediment levels. Timely replacement protects the RO membrane from chlorine and sediment.

SmartFlow™ Membrane (Stage 2): Replace every 12 months*. This membrane reduces dissolved solids and organic matter. Municipal water (pH 7.0-7.5) typically requires replacement every 12 months. Membrane life is affected by pH and water hardness; higher pH can cause leaks and shorten life. Replace when output, water quality, or production rate decreases.

*Filter life depends on water usage and water supply quality.

Arsenic Information

This system is tested for pentavalent arsenic (As(V)) at concentrations of 0.05 mg/L or less. It reduces pentavalent arsenic but may not remove other forms. Use only with water supplies having a detectable free chlorine residual or proven to contain only 50 ppb (0.050 mg/L) pentavalent arsenic. Chloramine treatment is insufficient for trivalent arsenic conversion.

Arsenic Facts:

Arsenic is a naturally occurring contaminant in groundwater, odorless and colorless. Public water utilities test for it; check with your utility or local health department for certified labs. Information is available at epa.gov/safewater/arsenic.

There are two forms: pentavalent (As(V)) and trivalent (As(III)). Trivalent arsenic is considered more harmful. Water may contain either or both. Special sampling is needed to determine arsenic types and amounts.

The AOS-HERO-CHR system is designed to remove pentavalent arsenic only and will not convert trivalent to pentavalent. In lab tests, it reduced pentavalent arsenic from 0.050 mg/L to 0.010 mg/L (USEPA standard). Performance may be limited by water quality (e.g., iron). Test your treated water to verify system effectiveness.

The SmartFlow™ Membrane must be replaced every 12 months to ensure continued arsenic reduction. Component identification and purchase locations are in the installation/operation manual.

Limited Warranty

Who is Covered: The original owner who purchased and installed the system.

What is Covered: Defects in materials or workmanship for 24 months from the purchase date. Excludes filter cartridges and systems not installed per instructions or that have been misused.

What A. O. Smith Will Do: Provide a replacement part or system to fulfill the remaining estimated lifespan/capacity. If an identical model is unavailable, a comparable replacement will be provided, potentially at an additional cost for upgrades.

What is Not Covered:

Filter cartridges and systems not installed or maintained per instructions.
Products not purchased from authorized resellers.
Implied warranties (merchantability, fitness for a particular purpose).
Incidental, consequential, special, punitive, or contingent damages, including water damage.
Damage from misuse, alteration, accident, improper installation, corrosive conditions, lack of potable water, extreme temperatures, sediment buildup, clogging, fire, flood, acts of God, or over-pressurization.
Claims related to excessive noise, smell, or taste of water.
Damage from non-genuine A. O. Smith parts.

Owner's Responsibilities:

Pay for labor or other expenses for removal, repair, or replacement, including shipping and materials, unless prohibited by state law.

How to Get Service: Contact A. O. Smith at 1-877-333-7108 within the warranty period. Provide proof of purchase and installation. A customer service representative will guide you through the process.

Warranty Registration: Not required, but recommended at aosmithatlowes.com/register for record-keeping.

State Law: This warranty grants specific rights; state laws may vary regarding limitations on damages.

Need Help?

For assistance, please call 877.333.7108.

Visit AOSmithatLowes.com/reviews to leave a rating or review.

A. O. Smith is not liable for consequential or incidental damages due to improper installation. Use only genuine A. O. Smith parts. Installation must comply with state and local ordinances.

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A. O. Smith AOS-HERO-CHR High-Efficiency Reverse Osmosis System