You should always try to get the original installer to fix the furnace. The original installation contractor will remember the layout of your home more easily. He or she will also be able to provide faster service on furnaces he or she has worked with in the past. This is not always a possibility, but you should always try to find the original contractor to do repairs on an oil furnace.

Try to find a contractor who is willing to give you an estimate on the total cost of the job. This may need to be a rough estimate as because it can be difficult to determine how much work will go into a repair job. There could be any number of things wrong with the furnace that aren't readily apparent.

Find reviews for every contractor you consider hiring for a job like this. Repair jobs are sensitive, so you need to know your contractor is skilled enough to handle the work.