I hope this is not a weird problem. I live in the Northeast and the past weeks has been very cold (single digit to high teens). My house description: my broiler is located in the basement toward the back of the house; I have a first and second level. During the cold weather (described above) two of my radiators located on first level (living room and close to the front door (living room radiator-wall-front door-second radiator) only one or two of the radiators’ sections got warm, but now that the weather is in upper twenty or above freezing, three to four of the radiators’ sections got very hot. Why is this? My basement is finish but not heated (no radiators or heat except from the boiler) and all other radiators on first and second levels are heating ok during both weather periods.