Yup: https://www.ecobee.com/faq/i-do-not-have-a-c-wire-or-common-wire-can-i-install-ecobee-residential-thermostats/ https://www.ecobee.com/faq/i-do-not-have-a-c

Yup: https://www.ecobee.com/faq/i-do-not-have-a-c-wire-or-common-wire-can-i-install-ecobee-residential-thermostats/ https://www.ecobee.com/faq/i-do-not-have-a-c-wire-or-common-...