A few weeks ago I wrote concerning the operation of my new geothermal unit-it runs for hours on end without shutting off. We have had an oil furnace for years which is my only frame of reference. We keep the thermostat at 67,and,even though it says it has reached 67, the furnace continues to run. The contractor came out and said eveything checked out. He didn't seem too concerned and never really answered my question about whether that was normal. Would/could someone out there describe to me what I should expect in terms of how my furnace should be running? Thanks. 

Your unit will run longer than your furnace did. The old furnace probably put out 80-100k btuh. Your geo unit is most likely half of that, thus a longer run time. Thats OK if your system was sized properly from the start

Most ANY thermostat will overshoot before being satisfied...meaning...if you have it set at 67, it will heat to 68 before shutting things off.

Also you could have a two stage unit and it's running in low for a longer time. It's actually more efficient to do that than running in high for less time.

Not just more efficient, but it should be more comfortable, too.

Thermostats have a bearing in cycles/hour. It's not impossible for something to be programmed wrong. Not sure what your temperatures have been, but I would expect some down time this time of year. The problem is there are a lot of factors so by and large, we wont get too excited if you are reaching set point.
Joe

I wonder that if it is "running for hours on end" in November, how will it meet the load in January? I hope it turns out to be a well-sized two stage unit perhaps with the last ton or so made up with heat strips. That might explain lengthy operation in moderate weather.

All of the above comments are valid - no cause for panic, but the situation bears watching as winter progresses.