Ecobee thermostat

Our Nest thermostat, about 8 years old, stopped working on its heat pump wire about a month ago. We did not know what was happening; why was the house cold? (Because the oil burner wouldn’t go on unless the temperature was below freezing, and it mostly wasn’t, but it was still cold because the heat pump wasn’t working.) The heat pump itself was fine, but the wire connecting the heat pump wasn’t working — apparently, a problem for Nest devices, we were told, by Surner. I replaced with Ecobee, and installed it last night. … so far, so good ….