I'm replacing my 30 plus year old furnace with a new 2-stage and variable speed furnace. For thermostat, the contractor will be using an Aprilaire model 8363 which is for a 1-stage furnace. The contractor explained to me that they do this all time......instead of putting in another wire (old thermostat has only 5 wires) to accomodate a thermostat designed for a 2 stage furnace (needs 6 wires), the new furnace's circuit board (?) is adjusted/programmed so the thermostat for a 1-stage furnace can be use.
Can you pair a 2-stage variable speed furnace with a thermostat designed for a 1-stage furnace without compromising the 2-stage and variable speed features of the new furnace?