Model: Looks like 7680B or 76808 Series 856
Serial Number: 047863650 (the "8" could be a "B")
Fan runs about 10 minutes after thermostat shuts down burner, then fan shuts off.
All else seems to be normal.
The new thermostat is for heating and cooling (Hunter economical model), but only two wires connected to the Rh and W terminals (this is a split-system, but there is a separate T-stat on wall for cooling). The heating T-stat has a typical adjustable arm for setting the temperature, but this arm sticks out of a solid state module (not connected to a mercury switch-type, snap action mechanism with the bi-metal coil).
There are two switches with a transformer in between. These switches and transformer are outside of the control box that is attached to the fan housing (the box with the Auto/Cont & Heat/Cool rocker switches on the box)
The one on top of the transformer is adjustable and marked:
F130-20F. Number on switch is 74T12 or 74112
The pointer is a little to the right of what must be the 105 index mark. The 100 index mark is not a mark but the actual number 100, which is just to the left of the 12 o'clock position in the pic. The next highest marked position to the right of the pointer is 110 (it's not an index mark, but the actual number 110.).
Switch on bottom is not adjustable and marked:
L-155-2, 7680-359
Thank you for any help.
