Our brief flirt with spring weather has ended (for now). This morning we woke up to -18 on the thermometer, and it's been below -14C all day (it's 2pm as I right this).
Our "furnace" (the 4kW duct heater that heats our home) turned itself off at 9am, and has been off ever since. That's 5 hours at -14C or colder without any heat on! What's more, the temperature has been slowly climbing all day thanks to the sunny weather—it was 20C when the heater stopped, and its 22C now.
I'll comment later to let you know what time tonight the heater comes back on.