How-to
How to Set a Thermostat So the House Stays Even
An uneven house is usually a filter, a closed vent, or a setpoint that jumps four degrees at once. The thermostat can still make it worse if the fan is left on or the schedule is fighting a hold.
The fan
Leave it on Auto. On runs the blower all day and stirs dust onto a coil that may still be wet. The house feels drafty in the rooms near the returns, and the far room does not get warmer. The same point is in the summer half of a year-round plan.
How far to move it
Two degrees. On a heat pump, a four-degree jump is how the electric strips come on, and the bill shows up later as 'the system is getting old.' Heat pumps past ten years do this sooner. A gas furnace will catch a bigger jump, but the last room on the duct run still lags until the rest of the house is done.
One setting
If the thermostat is on Hold and also running a schedule, it is fighting itself. Pick one. Holding 68 in the day and 65 at night is enough of a setback. Dropping it to 60 and then asking for 72 at 6 a.m. is why the bedroom over the garage never catches up before you leave.
The room that lags
Look at the filter and at that room's supply. A vent closed for the winter, or covered by a bed, will not be fixed by a new thermostat. Open it before you replace the stat on the wall.