I have several questions all in one about a wood furnace. 10 points for best answer!?

Thats dangerous, the fan, (big squirrel cage fan), should turn on and stay on as long as any heat is being produced, If that fan is not running the ducts will get hot and maybe hot enough to cause some serious problems, besides just ruining the air ducts, it could catch fire.

It is normal for the gas part of the furnace to kick on in about 2 or 3 minutes if the regular furnace does not get the house warm enough. The gas portion should not kick in if the fan is not on, as well as the little vent fan.

In an emergency, you can turn it on for a few minutes, but no longer, no gas.

Call the installer, they installed it incorrectly. They are responsible to do it right. You may be getting into trouble by doing any self fixes, then they will say you broke it.

I use a fireplace, (as well as the furnace), and I still have an emergency back up LP heater. Go get one, about $200, better to do that now, who knows, the furnace might give out again when it is 5 below.

Call the installer is my suggestion.

the wood stove comes with a limit switch that switch has a dial inside of it with three pointers one pointer turns the fan on when desired temp is reached and should be pointed at 90 and one turns the fan off when stove cools off at 70 if they aren't in those places then carefully without making the dial turn push those pointers where they are suppose to be.

next is to put a damper in your heat line so the wood stove air doesn't go into the gas furnace very important to have this done properly. your pro ripped you off so sue him and get a real professional there to reinstall it