How a faulty smart thermostat caused huge electric bills for one customer

HOUSTON – Smart appliances and thermostats are supposed to help users save money because you can adjust and control devices even when you’re not at home. But one Houston woman says her smart thermostat cost her thousands of dollars in sky-high electric bills.

What happened

“I would never have dreamed that it was my thermostat,” Nichole Medrano told consumer expert Amy Davis.

When Medrano moved into her apartment 3 years ago, she hired Vivint Security to install cameras, a smart doorbell and a smart thermostat. It wasn’t until last fall that her electric usage shot way up, costing her $2,800 for four months of electricity.

She called Reliant after her first abnormally high bill in October 2020. Reliant checked Medrano’s meter and assured her that it was accurate.

“I didn’t have any new appliances,” Medrano said. “I didn’t have company at that time because of COVID.”

Despite that, her bills and usage continued to mysteriously increase from her average of 700 kilowatts and about $120 to more than 5,000 kilowatts and a bill of more than $1,000. Nichole paid what she could to make sure her lights stayed on while Reliant helped her investigate.

The investigation

After several weeks of monitoring her usage, turning off appliances and troubleshooting, Reliant Energy discovered the smart thermostat in her apartment was the culprit. A Reliant representative told us the thermostat was communicating with the furnace and turning it on every 15 minutes. Since the air handler fan was not on, the hot air was never delivered into Nichole’s apartment. It’s why she didn’t notice a change in the temperature. It was an issue Reliant has never encountered before.

The usage went back down when Medrano contacted Vivint security and the company reset her system. That stopped the bleeding, but the damage to Medrano’s budget was done.

Vivint’s response

Vivint offered Medrano just $1,400 to help cover the $2,800 in excess charges she paid Reliant. When consumer expert Amy Davis contacted Vivint, a representative reached out to Medrano with a better offer of $2,700.

Davis asked Vivint if this issue has happened before with other customers.

By email, a Vivint representative told Davis, “In rare conditions with a previous version of the thermostat, relays in the hardware can get stuck in an on or off position until the thermostat is power-cycled.”

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Passionate consumer advocate, mom of 3, addicted to coffee, hairspray and pastries.