I have a Cleveland Dornback furnace that is about 25 years old. We cannot find parts for it anywhere in the area. It has something wrong with the thermocoupler. I mean, when it shuts itself down I can go down and give the thermocoupler a light thump and it flames on. But within the hour it is back to just the pilot light again. Sometimes it turns itself back on again, but most times it doesn't. Then there are the days when it feels like making this place like the Bahamas....and it gives off enough heat to make you want to open windows. I really don't want to have to convert to forced air as I do like the gravity heat itself...is there anything I can do to repair the thermocoupler or where I can find a new one???????? Or is my only option going to be to replace it and how much work would I be looking at to do it myself? Thanks in advance.