with the cold weather that finally hit the northeast i have been running the defiant all day and night vs. a fire at night and maybe one in the morning if it's chilly. my boiler doesn't even know that it's cold out as it is only heating the water tank and a couple of rooms in the basement. upstairs it's running about 70 to 72 in the center of the house. right now at almost 2 am it is 15 below zero and very windy. the front porch is creaking and the back deck sounds like someone is hitting it with a sledge hammer