I have an old house that is heated by hot water radiators. I live in Minnesota and I am thinking about supplementing with a wood stove. Since a central thermostat regulates my house temp, is there any chance that my water radiators would have a problem with freezing if I used a wood stove. Several of the radiators are along the walls in different rooms far from the thermostat. I plan on putting the wood stove in the same room as the thermostat. Does the water in the radiators circulate even when the thermostat does not kick the boiler on?