We have never had any control over the heat in our older home. The furnace had to be manually turned off to stop the heat. Just installed a new programmable thermostat with high hopes. Unfortunately, we are still unable to lower the temp from the thermostat. Help, we're baking here!
A thermostat works on 24 volt DC. In order to use the 120 volt housepower, the furnace relies on a transformer to convert the electricity to a usable state. First check to see if the transformer is putting out the 24 volts. If not, the transformer is bad. If it does, go up to the thermostat and see if the 24 volts are present at the wire ends. If not, you have a broken wire. Do these checks and see what happens before going any further.