Introducing the Voltex® X

The most adaptable residential heat pump solution for energy savings, installation flexibility, and smart performance.

Voltex® X Outdoor Split System Heat Pump Water Heater

Introducing A. O. Smith's new Voltex® X—the most adaptable residential heat pump solution for energy savings, installation flexibility, and smart performance.

An outside heat pump unit paired with an indoor tank sized for the home, forming a complete set.

Partnered with Panasonic, this unique, high-efficiency heat pump split-system design uses an outdoor heat pump and an indoor storage tank, making it ideal for homeowners seeking an energy-efficient water heater solution with limited physical space or ventilation.

The Voltex® X is an ENERGY STAR® certified, low-GWP heat pump water heater that delivers exceptional efficiency with a first hour rating of up to 95% and a standard 4.5 kW output—no backup element needed. Using CO₂ refrigerant with a GWP of just 1 and an A1 safety rating, it offers exceptional sustainability and safety.

The flexible split-system design features multiple indoor tank sizes and a quiet outdoor heat pump, making it ideal for tight spaces. It installs easily with standard connections, long pipe runs, and optional ground, wall, or rooftop configurations. Unlike integrated units, it requires no indoor air ventilation and can be transported on its side.

Built for cold-climate performance, the system operates efficiently from –25°F to 109°F, outperforming standard integrated heat pump water heaters in winter conditions. It maintains high efficiency without relying on electrical resistance elements in freezing temperatures. Smart features through the iCOMM™ app include remote monitoring, guest mode, leak detection, demand-response readiness, and optional automatic water shutoff.

Voltex® X Features & Benefits

Flexible Installation

Save space and energy with this quiet hybrid heat pump water heater, offering flexible outdoor installation (on the ground, on a wall, or on a roof) and an indoor storage tank that plugs into a standard outlet, providing a reliable, easily programmable hot water solution for your home.

Superior Cold Climate Performance

Designed to work in extreme weather, this heat pump water heater runs efficiently in temperatures from -25°F to 109°F, delivering energy-saving performance even in harsh cold where standard heat pumps struggle.

Advanced Energy Savings

With up to 3.8 UEF, it can save homeowners an average of up to $600 per year in energy costs.*

*Comparing an 80-gallon heat pump against a pre-2015 similarly sized standard electric using DOE EF to UEF conversion rates. Savings may vary.

Environmentally Friendly

Features CO₂ refrigerant with a GWP of 1 (lowest environmental impact), along with an A1 safety rating for non-toxic, non-flammable performance.

Smart Features & Added Protection

Stay in control with smart features powered by the iCOMM™ mobile app, including guest mode, leak alerts, and demand-response/time-of-use energy savings, plus options for automatic water shutoff for extra peace of mind.

How Voltex® X Works

Step 1

Cold water enters the tank through a dip tube, which forces it to the bottom of the tank while pushing hot water out through the top connection.

Step 2

The hot water leaving the tank is tempered to 120 degrees—or to the user’s preference—using a mixing valve.

Step 3

The outdoor unit begins pumping cold water from the bottom of the tank, starting the heating cycle.

Step 4

A fan pulls air across an evaporator coil, transferring heat from the air into the refrigerant inside the coil.

Step 5

The compressor starts and compresses the CO₂ refrigerant, raising its pressure and temperature as it is pumped through the inner tube of a concentric heat exchanger.

Step 6

Water flows through the outer tube of the heat exchanger, absorbing heat from the refrigerant.

Step 7

Hot water is pumped back into the top of the tank.

Step 8

This process continues until the temperature at the bottom of the tank reaches 120 degrees.

Voltex® X Components

Outdoor Heat Pump Unit

Voltex® X Outdoor Split Heat Pump Water Heater Model HPACO-45 100

ENERGY STAR® certified—Up to 3.80 Uniform Energy Factor (UEF)
Up to 95-gallon first hour rating
Backed by a 10-year warranty

Pick Your Indoor Tank Size

Still Have Questions?

The Voltex® X by A. O. Smith is a split-system heat pump water heater with an outdoor unit and indoor storage tank, offering high efficiency, smart features, and flexible installation. Unlike integrated heat pump water heaters, it doesn’t require large indoor air volumes, making it ideal for homes with limited space.

This heat pump delivers a up to 95% first hour rating and advanced UEF performance, helping homeowners save on average up to $600 on annual utility bills compared to standard electric water heaters. It operates efficiently in temperatures as low as –25°F, providing reliable hot water even in cold climates.

Voltex® X offers multiple indoor tank sizes, including 50-gallon low boy, 50-gallon short, 50-gallon tall, 66-gallon tall, and 80-gallon tall. There's only one outdoor heat pump unit to choose from that installs easily outside, freeing up indoor space, and supports flexible configurations, including ground-mount, rooftop, or side-of-building installations.

Need help picking the right size? Use our Water Heater Selector Quiz!

The system connects to the iCOMM™ app for remote monitoring and control. It includes guest mode, leak detection alerts, optional automatic water shutoff, demand-response capability, and an anti-freeze valve kit to prevent freeze damage during power loss.

Yes, it uses CO₂ refrigerant with a Global Warming Potential (GWP) of 1—the lowest available—reducing environmental impact compared to standard refrigerants. The system is A1 rated, meaning it’s non-toxic and non-flammable, offering safe, sustainable performance.