I have an old wood furnace that I use for heating our home. Recently it has been acting funny. There is a switch on it where you can turn it on to blow air into the stove to get the fire going and then on the other side of the switch it has auto where the inside theromstat controls it. Well so you turn the switch on ON and it works fine, but it stays on... which is normal. But I need it to work on auto so it can work with the theromostat so nothing will burn up. Please if you have any ideas or suggestions please reply.

By the way, I've already tried replacing the theromostat... it didn't work