I live in Tarquinia, a few km northern than Rome, on the Tirreno sea.
Winters are usually mild, although this one has seen minimum temp of -6°C and my lemon trees suffered a bit (but still alive).
I use the heater in winter, but it was quite useless because of I was running without thermostat, and the water was not sufficiently hot... now it seems working well, but springs arrived, finally...