Reply #4: Do you have hot water baseboard or radiators?

[amerikat]

I have hot water radiator heat. My furnace comes on sometimes when the
thermostat is not calling for heat. The furnace guy told
me my furnace had internal controls that turn the furnace on
to maintain a certain level of heat in the system. This is
so that it doesn't take so long to get heat when the thermostat
calls for heat. I turn mine off at the switch. I'm going to have
a new furnace soon and will have that feature disabled.
Hope this helps.