A. O. Smith AOS-DFRO800 Tankless Reverse Osmosis review
By Daryna Klochko · Published · Specs checked Oct 15, 2026 · 
Scores 9/10, tied for 13th of the 20 RO systems we track. At $474.99 it costs more than the category median of $459.99. Its cartridge cost of about $290 a year is above the $205-a-year median of the 19 RO systems with a stated cartridge cost. Its 2-year warranty is longer than the 1-year category median.
You need a certified health claim: its listing covers TDS only, unlike 12 of the 20 RO systems
- Price
- $474.99
- Certified for
- TDS
- Flow
- Not stated
- Cartridge life
- 365 gal
- Cost per year
- $290
- Warranty
- 2 years limited
Certification
Listed by IAPMO under NSF/ANSI 58 for TDS, checked Oct 15, 2026. A. O. Smith also claims 1 more substance that is not in the listing. Search the IAPMO listings
- TDS
A. O. Smith also claims Chlorine: brand claims, not in a certifier listing.
The contaminants or other substances removed or reduced by this water treatment device are not necessarily in your water. Listing checked on Oct 15, 2026. What a listing means and what it doesn't
Specs and sources
Checked Oct 15, 2026 · source under each valueFiltration
Cartridges and install
Buying
Warranty, returns and shipping
Warranty: 2 years limited. Returns: Set by the retailer. Shipping: not stated by the brand. Source: A. O. Smith data sheet, checked Oct 15, 2026.
Source: A. O. Smith data sheet, checked Oct 15, 2026.
Compared with similar RO systems
All 20 RO systems →| Model | Price | Certified for | Cost per year | Warranty | Score | Where to buy |
|---|---|---|---|---|---|---|
| Aquasana SmartFlow Reverse Osmosis | $449.99 | Lead · Cysts +9 | $310 | 2 years | 9.25/10 | Check price → |
| Brondell Circle RC100 Reverse Osmosis | $449.99 | Lead · Cysts +12 | $205 | 1 year limited | 9.75/10 | Check price → |
| Frizzlife PD600-TAM3 Tankless Reverse Osmosis | $469.99 | Brand claims only | $107 | 1 year | 9/10 | Check price → |
| A. O. Smith AOS-DFRO800 Tankless Reverse OsmosisTHIS MODEL | $474.99 | TDS | $290 | 2 years limited | 9/10 | Check price → |
| Brio G20-U ROSL700 Tankless Reverse Osmosis System | $499.99 | Brand claims only | $340 | 1 year (limited) | 8.75/10 | Check price → |
What owners say
Checked Oct 15, 2026Only 19 ratings on Amazon, too few to call. In our score this is 1.75 of 2 points. How we score
Store ratings change over time; the date shows when we checked.