Can I use our house furnace blower to circulate heat from a fireplace insert?

Both answer would be correct. If you choose to run the furnace blower fan on ON all the time. Please make sure that you change your furnace filter more often. You should change it every 30 days. A basic pleated filter will do the job. Lastly, not knowing the layout of the room. But you could add a return to the room the fire place is in. Then with the blower on it will suck the heat out of that room and distribute it though out the home. How cost effective that would be well... Ill leave that to someone else.