Open all of he heat registers in your unused rooms. The heat registers are the vents on the ceiling or the flooring. If you close the heat registers, the air in your home will be unbalanced. The cold air in your rooms will float into the rest of the house making your furnace ineffective.
Upgrade your thermostat. If you are not using a digital thermostat, the temperature in your home could vary up to 10 degrees. Digital thermostats take a digital temperature of the air in your home making the furnace more efficient.
Leave the thermostat where you want it. It will take a little while for the furnace to heat your home. Do not put the thermostat any higher than where you want it because the furnace will be overworked. This can also send a spike to your power bill.
Check the filters on your Bothel furnace. The filter is located in the filter service panel. Lift the panel up to reveal the filter. Pull the filter out and check it for dust or dirt. Replace the filter if needed. You can find filters at local hardware stores.
Call a trained HVAC technician to diagnose any wiring problems with your furnace if these methods don't work. HVAC technicians have specific training on rewiring or replacing faulty parts.