Hi,



I have just moved in to a 30-year-old house and I am having trouble with the
thermostat. The original one is an old combined heat/AC rotatable type.



I am replacing it with a new programmable one.



There is a blue Honeywell type box on the face of the furnace with a
terminating stripe down the side, what is its function. I suspect it
supplies low DC voltage, but not sure. I notice that the line for the
heating goes directly to the furnace igniter, should it not go to the
Honeywell box.



Any help or schematics would help.



Thanks.