I may not have accurately described the problem with my Totaline P474-1035 programmable thermostat.

The furnace does turn "On" and "Off" (so the thermostat wiring is OK) but the furnace doesn't respond to the "Heat" setpoint on the thermostat.

For example, if the setpoint is 82 degrees, the furnace doesn't come on when the house temperature drops below 82 degrees (sometimes, the furnace doesn't come on when the house temperature falls to 73 degrees).

When I push the "UP" button so the display shows 90 degrees, the furnace won't come in for a looong time (even hours!)