A. O. Smith S4 is a 100% RO water purifier with a 2-year warranty on the RO membrane. It incorporates a 5 stage purification system, along with a Side Stream RO Membrane Technology. It uses one of the latest technologies that is utilized in the water purification process. A. O. Smith S4 RO Water Purifier works under the principle of RO (Reverse Osmosis) technology which is one of the most effective process for treating water. In this process, water under pressure is passed through a semi-permeable membrane. Purified water is collected for drinking in a storage tank and impurities in the water are flushed down the drain.






Why Choose Our Product


  • 5 Stage Purification

    Pre-filter + Sediment filter + Pre Carbon filter + RO Membrane + Silver Activated Post Carbon. In A. O. Smith X4 100% of the water passes through the RO membrane.

  • Advanced Patented SSM Technology

    Suitable for water with low and high (upto 2000 ppm) TDS. Less water is wasted and improves pure water recovery.


  • Pre-filter & Sediment filter

    For effective removal of suspended solids and sediment from water and to ensure better life of RO membrane.


  • Twin Advanced Alert Technology

    For Sediment + Pre Carbon and RO membrane + Silver Activated Post Carbon filters change.

  • Tank Overflow Protection

    For Sediment + Pre Carbon and RO membrane + Silver Activated Post Carbon filters change.

  • Large Storage Capacity

    Pure water storage capacity of 9 Liters

Product Dimensions (H x D x W)503 mm x 325 mm x 314 mm
Net Weight8.8 kgs (approx.)
Gross Weight11.9 kgs (approx.)
Flow rate*Up to 15 liters per hour
Storage tank capacity9 litres (approx.)
Purification technologyRO (Reverse Osmosis)
5 Stage Purifying TechnologyPre-filter + Sediment filter + Pre Carbon filter + Side Stream RO + Silver Activated Post Carbon filter.
Membrane typeThin film composite RO membrane
Material of construction for plastic partsFood safe, non-toxic, engineering grade plastics
Pump typeDiaphragm pump, 24VDC, 0.26 Amps, Operating Pressure 125 psi (Max.)
Input Voltage150 – 300 VAC
Power rating (Max)48 Watts
Pressure Rating***7 psi to 30 psi
% Recovery**Up to 30%
TDS reduction**≥95% (approx.)
* Flow rate depends on variable factors such as feed water pressure, feed water characteristics and condition of the membranes and filters. 
** Recovery and TDS reduction percentages also depend on variable factors such as life and condition of the membranes and filters, feed water pressure, feed water characteristics. 
*** If input pressure exceeds 30 psi, a pressure reducing valve needs to be installed at the feed line. If the pressure is lower than 7 psi, a booster pump needs to be installed. 

 **Design, feature and specifications mentioned are subject to change without notice

StageFilterDescriptionFilter Life (Months)Price (PHP)
110µm PP MMPFilters rust, sand, other large particles and solid impurities suspended in water6-8350
2Carbon BlockAbsorbs chlorine, mold, disinfection by-products, odors, discolorations and other materials in the water6-8720
3PP SedimentFilters finer particles and lengthens life of RO membrane6-8500
4Sidestream RO MembraneRemoves bacteria, viruses, heavy metals, pesticide residue, and other harmful substances. Effective for microbiological and chemical purification24-322500
5Silver Activated Post Active CarbonRegulates taste and smell of water, keeping it fresh; silver ions prevent growth of bacteria12-16600

Based on consumable costs, average cost per liter of water at 0.85 php

User Manual and Leaflets
Attachment Size
S4 User Manual.pdf 1.3 MB
A. O. Smith S4 Certificate.pdf 327.2 KB