We have lived here for about 5 years and the heat has always behaved the way it should other then an occasional frozen pipe on the second floor and a broken circulator.

The house has FHW by Oil, 3 zones: First Floor, Second Floor, Workshop. For some reason we have had this odd thing going on for the past week. The second floor is constantly hot, like 73 degrees. The first floor is steady as it should at 68 degrees. This is with temps outside around 30-35. I have the thermostats set up to turn the heat down to 58 at night and for all the time we have lived here the second floor would be hitting that by the morning, just before it goes back up to 68. Now, I get up in the middle of the night and it is still in the 70's. I even turned it off at the thermostat, the radiators are still hot. I took the thermostat controller right off the wall, no diff. The funny thing is if I check the zone control on the boiler, the zone is not calling for heat, but the radiators are always hot.