I decided to replace my 6 year old digital thermostat (Honeywell), with a
new programmable thermostat (Hunter).

The wiring is the basic White,Yellow, Green, Red.

The new thermostat had the following connections:

G - RC - RH - Y/0 - W/B - Y1 (A jumper wire between RC & RH came
pre-installed).

I connected the wiring & ran the a/c, it worked fine.
I kicked on the heat, it ran fine & cycled off but, the flue purge motor
continued running after the furnace had shut off. (It never did this with
the old thermostat.). I had to shut off the motor with the rocker switch on
front of the furnace.
I double checked all connections & they were secure & correct.
I double checked that the switches on the back of the thermostat were set to
"STD" as opposed to "HP" & "HG" as opposed to "HE". I ran the furnace, same
thing, purge motor kept running.

I did some poking around on the net & came across several websites that said
to disconnect G, & if the motor continued to run, the problem was most
likely a stuck relay. I had an electrician look it over & he said he didn't
think it was a stuck relay & he suggested to re-connect the old Honeywell
thermostat & see if the motor continued to run.
It didn't.

I assumed I had a bad thermostat. I returned the Hunter & purchased a
Honeywell. I connected the new Honeywell, fired up the a/c, everything
worked fine. A few minutes later, I fired up the furnace, let it run, cycle
down & shut off...the purge motor continued to run.

Obviously, it wasn't the thermostat. I re-connected the old Honeywell, fired
up the furnace, let it run, cycle down & shut off, the purge motor also shut
off.

Can anyone shed some light on this. I'm not the most mechanical person but,
something that should be simple has me stumped.