Ariston NUOS Side-Connect 80 Gal
#11 in 80 GallonFull review
A non-Midea design with a leak sensor built in and a 10-year tank and parts warranty, sold through plumbing dealers. It is louder than most here.
3.5/5
Navien’s stainless-tank hybrid, sold through plumbers, with a 10-year warranty that includes a year of labor. Its heat pump stops below 41 °F room air, so it suits a basement more than a cold garage.
- 80 galSize
- 4.05UEF
- 85 galFirst hour
- 240 VPower
- 41 °FRuns down to
- 10 yr tankWarranty
See it at Navien
No store we check sells it online; the maker lists where to buy or who installs it.
Pros
- Stainless steel tank instead of glass-lined steel
- Very efficient: a certified UEF of 4.05, about a quarter of the electricity of a standard electric tank
- Built-in Wi-Fi: set schedules and vacation mode from the NaviLink app
Cons
- Switches to the backup element when the room drops below 41 °F, so it saves little in a freezing garage
How it scores
The rating comes from 5 measured or published factors, each scored 0-100 against fixed reference points for its size. How we rank explains each one.
Specifications
| Model number | NWP500S080AUMB |
|---|---|
| Ratings (ENERGY STAR) | |
| Size (nominal) | 80 gal |
| Tank volume (measured) | 74 gal |
| Uniform Energy Factor | 4.05 |
| First-hour rating | 85 gal |
| Draw pattern | High |
| Yearly energy use | 1,265 kWh |
| Heat pump cut-off (low) | 41 °F |
| ENERGY STAR ID | 4016030 |
| Installation | |
| Power | 240 V |
| Circuit | 30 A, 208/240 V |
| Backup element | 5,000 W |
| Operating air range | 41 to 113 °F |
| Minimum room size | 640 cu ft |
| Size | 71.6 in tall, 25 in across |
| Weight | 220 lb |
| Refrigerant | R-134a |
| Features | |
| Wi-Fi | Built in |
| App | NaviLink |
| Leak detection | No |
| Modes | Energy Saver, Heat Pump, High Demand, Electric, Vacation |
| Warranty and models | |
| Warranty | 10 yr tank, 10 yr parts, 1 yr labor |
| Released | 2025-06 |
Alternatives in this size
GE Profile 80 Gal 120V
#12 in 80 GallonFull review
The most efficient 120 V plug-in here, and the quietest, for replacing a gas tank without new wiring. It can be rewired for 240 V later if the household outgrows it.
GE Appliances Wayfair $3,042$3,042
Rheem ProTerra 15 A 80 Gal
#14 in 80 GallonFull review
The ProTerra for a home that only has a 15 A, 240 V circuit, such as one left by a small electric tank: it avoids rewiring but gives up some efficiency and first-hour delivery.
Compare
Compare the Navien NWP500 80 Gal with any other heat pump water heater →
More from Navien: every Navien product ranked.