Richard Trethewey is the heating and plumbing expert on the popular PBS home improvement show “Ask This Old House.” For an October 2018 episode, Trethewey met with homeowner Scott Sanders, who needed to replace an ailing 20-year-old electric tank water heater.
Trethewey recommended an electric hybrid water heater to replace the existing tank unit. In this case, he installed the A. O. Smith Voltex Residential Hybrid Electric Heat Pump Water Heater. With a Uniform Energy Factor (UEF) of up to 3.42, the Voltex water heater could significantly reduce the Sanders family’s monthly electric bill. In addition, it could easily be installed without any upgrade to the home’s electrical service.
“We thought about going the tankless electric route, but soon realized that we couldn’t,” Sanders says. “We currently have 150-amp service, and the tankless electric would have required a minimum 200 amps.”
Sanders was enthusiastic about the Voltex option.
“That choice sounded excellent because of its potential for big energy savings,” he says.
The Voltex unit was installed in the spring, though the episode aired in October.
“Initially, I ran it on Efficiency-Only mode,” Sanders says. “In the spring, it would only heat the water via the heat pump and didn’t need to circulate back through the electric elements to add more heat. We’ll run it in Hybrid Mode most of the year, especially during the cooler months and times when relatives visit.”
Sanders knew that his old 40-gallon water heater was in its final months of life.
“We were noticing that the temperature would drop in the middle of a shower,” he says. “Since were are not permitted to expand back through the water meter and did not have a separate expansion tank, I had a drain on the cold side, plus pressure relief that went to an outside drain to deal with the expansion. There was a steady drip that we wanted to eliminate.”
The Sanders home has two showers, no bathtubs, a kitchen sink, a guest bath sink and a double-sink in the master bath. The Voltex unit needed to provide hot water for Sanders, his wife and their 11-year-old daughter.
“Our peak demand would be running two showers simultaneously, which sometimes happens and is very common when relatives visit,” he says.
The Voltex water heater was installed in the garage. Sanders noticed immediately how the new unit pulls heat and humidity out of that space.
“It’s probably 10° cooler than what we were previously experiencing,” he says. “In the summer, the garage temperature can easily hit 100°.”
Sanders found the Voltex installation and TV filming to be an interesting experience.
“We all got to get our hands dirty, which was fun,” he says “The Voltex installation went smoothly. The installers were all pros, so it was a very seamless process.”
The “Ask This Old House” team told Sanders that the No. 1 maintenance tip was to allow sufficient airflow around the Voltex unit.
“They said it’s important to not crowd it so there’s adequate airflow,” Sanders says.The Sanders family has been thrilled by the energy savings that their new Voltex water heater has provided. In the first February following the Voltex installation, the Sanders’ monthly electric bill dropped by $45 compared to the previous February. Average KWH/day dropped to about 23 in February 2019 compared to 36 the previous February.