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. A Reliant representative told us the thermostat was communicating with the furnace and turning it on every 15 minutes.