A.O. Smith Adapt ATHR-199M
#13 in GasFull review
A premium whole home heater for buyers who want built in recirculation and top efficiency and can pay for it.
Amazon $2,346.08$2,346.08
3.4/5
A budget condensing heater for natural gas homes that want PVC venting and lower gas bills, if you can live with an unclear warranty.
- 163,000 BTU/hHeating power
- 9.4 GPMMax flow
- 0.91UEF
Check price at ThermoMate$1,099.99
Price checked October 31, 2026. As an Amazon Associate we earn from qualifying purchases.
Pros
- Condensing at 0.91 UEF for well under the big brand price
- Vents with PVC, cutting installation cost
- Rated for three showers at once from 62°F inlet water
Cons
- No published warranty terms on the product page
- Natural gas only and sold only by ThermoMate
- Needs a condensate drain and a neutralizer, sold separately
How it scores
The rating comes from 4 measured or published factors, each scored 0-100 against fixed reference points for its fuel. How we rank explains each one.
Specifications
| Model number | RTC68iN |
|---|---|
| Heating | |
| Fuel | Gas |
| Gas type | Natural gas |
| Gas input | 163,000 BTU/h |
| Max flow | 9.4 GPM |
| UEF | 0.91 |
| Condensing | Yes |
| Installation | |
| Venting | Indoor |
| Vent type | PVC |
| Weight | 50 lb |
| Features | |
| Built-in recirculation | No |
| Wi-Fi | No |
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