This article provides a comprehensive overview of the AO Smith AO-US-200 2-Stage Water Filter, including its installation process, maintenance requirements, and warranty details. The system is designed for under-sink installation and features Cellarium® filtration technology that reduces harmful contaminants while preserving beneficial minerals in the water. Based on the manufacturer's official documentation, the following sections outline the key aspects of the AO-US-200, including step-by-step installation instructions, tools required, and warranty information.
Overview of the AO-US-200 2-Stage Water Filter
The AO-US-200 is a two-stage water filtration system designed for installation under a kitchen sink. It is engineered to provide clean, great-tasting water by reducing harmful contaminants such as chlorine, sediment, and bad odors. The system utilizes Cellarium® technology, which is designed to retain beneficial minerals in the water while filtering out harmful substances.
The filter is designed for use with potable water and must be installed in a location that prevents water damage in the event of a leak. The recommended replacement frequency is every 6 months or every 500 gallons of use, whichever comes first. Users are advised to use only certified, genuine A. O. Smith replacement filters to maintain the system's performance and contaminant removal capabilities.
Installation Requirements and Tools
Before beginning the installation process, users must ensure that all components included in the packaging are present and undamaged. The manufacturer recommends the following tools for installation:
- Variable speed drill with a 7⁄32″ bit
- Adjustable wrench
- Measuring tape
- Bucket
- Phillips head screwdriver
- Hammer
The faucet may be mounted using an existing hole for a sprayer nozzle or soap dispenser, or a new hole may be drilled with a diameter no larger than 1/2″. Users who require pipe cutting or drilling are advised to consult a professional to ensure proper installation.
Step-by-Step Installation Guide
Step 1: Install the Brass Tee and Connect Tubing
- Turn off the cold water supply to the sink.
- Using an adjustable wrench, disconnect the water line.
- Attach the brass tee (B) to the shutoff valve and re-attach the cold water line to the brass tee.
- Attach the white tube (A) to the brass tee (B). Slide the brass nut (C) onto the tubing with the threads facing the end of the tube.
- Slide one plastic collar (D) onto the tube.
- Place the brass tube insert (E) into the opening of the tube.
- Push the tip of the tube into the opening of the brass tee.
- While holding the tube in place, tighten the brass nut to compress the plastic collar and create a seal.
Step 2: Faucet Installation and Connection
- Place the faucet rubber washer (F) between the faucet and sink.
- Under the sink, thread the faucet spacer (G), faucet washer (H), and faucet nut (I) onto the tubing.
- Tighten the faucet nut to secure the faucet to the sink.
- Connect the tubing to the base of the faucet. Slide the chrome nut (J) onto the tubing with the threads facing the end of the tube.
- Slide the second plastic collar (D) onto the tube.
- Place the plastic tube insert (L) into the opening of the tube.
- Push the tip of the tube into the faucet base.
- While holding the tube in place, use a wrench to tighten the brass nut to create a seal.
- Avoid over-tightening the connections to prevent damage.
Step 3: Install the Filter System and Connect Supply Lines
- Select a location under the sink that is at least 12 inches from the bottom of the cabinet to allow for filter replacements and easy access to the cold water supply.
- Use the mounting holes on the back of the filter unit to mark the wall screw placements. The distance between the holes is 2.55 inches.
- Use a 7/32″ drill bit to drill holes for the plastic anchors (K). Carefully tap the anchors into the drilled holes with a hammer.
- Mount the unit to the wall using screws.
- Pull the protective plastic strip from the battery compartment. The red LED should flash and beep five times to indicate that the battery is installed correctly.
Step 4: Install the Filter Sumps
- Attach each sump to the bottom of the unit housing.
- Align the connection points, push the sump up, and turn it to the right to secure it in place.
Warranty and Support
The AO-US-200 comes with a limited 1-year warranty that covers defects in materials or workmanship. This warranty applies only to the original owner who purchased and installed the system. The warranty does not cover damage caused by improper installation, misuse, or the use of non-genuine A. O. Smith replacement parts.
To qualify for warranty coverage, users must provide proof of purchase from an authorized A. O. Smith reseller and proof of proper installation. If a defect is found, the manufacturer will provide a replacement unit or component at no additional cost, provided the claim is made within the warranty period. If the original model is no longer available due to industry standards, product improvements, or obsolescence, the manufacturer will provide a comparable replacement, but the user may be charged for the additional value of the new item.
Warranty registration is not required for coverage, but users are encouraged to complete the online registration form at aosmithatlowes.com/register to ensure their purchase is recorded.
Maintenance and Filter Replacement
The AO-US-200 requires regular maintenance to ensure optimal performance. The manufacturer recommends replacing the filter every 6 months or after 500 gallons of use, whichever comes first. Users are advised to use only genuine A. O. Smith replacement filters to maintain the system’s contaminant removal capabilities.
Filter replacement should be performed according to the instructions provided in the owner’s manual. The system should be turned off during filter changes to prevent water damage. After replacing the filter, users should run the tap for a few minutes to flush out any air trapped in the system before using the filtered water.
Conditions That Void the Warranty
The warranty does not cover damage caused by the following conditions:
- Exposure to highly corrosive water conditions
- Lack of a continuous supply of potable water
- Operation outside of factory-calibrated temperature limits
- Installation in direct sunlight or freezing temperatures
- Sediment buildup or clogging due to failure to replace filter cartridges
- Damage from fire, flood, or acts of God
- Over-pressurization in the water line
- Use of non-genuine A. O. Smith parts, including replacement filters, faucets, or diverter valves
The manufacturer also disclaims liability for claims related to excessive noise, smell, or taste of water. Users are responsible for all labor and other expenses associated with the removal, repair, or replacement of the water filter or any component parts claimed to be defective.
Contact and Support
For assistance with installation, troubleshooting, or replacement parts, users are encouraged to contact A. O. Smith at 877-333-7108. The manufacturer provides installation videos and detailed instructions on its website, which can be accessed by scanning the provided QR code in the manual or visiting aosmithatlowes.com.
Users who encounter missing or damaged parts should call the support number immediately and not proceed with installation until the issue is resolved. The manufacturer will provide necessary replacement parts at no additional cost if the issue is within the warranty period and the system was installed correctly.
Conclusion
The AO Smith AO-US-200 2-Stage Water Filter is a reliable under-sink filtration system that provides clean, great-tasting water by reducing harmful contaminants while preserving beneficial minerals. The system is designed for easy installation and requires regular maintenance, including filter replacement every 6 months or 500 gallons. The manufacturer provides detailed installation instructions and a limited 1-year warranty to support users.
Users are advised to follow the installation guidelines carefully and use only genuine A. O. Smith replacement filters to maintain system performance. In case of any issues, the manufacturer offers customer support through a dedicated hotline and online resources.
By following the provided installation and maintenance steps, users can ensure the AO-US-200 continues to deliver clean, high-quality water for hydration, cooking, and other household uses.