Surgery - Colorectal. In brief: Yes, most docs can. Most hemorrhoids should first be treated by conservative measures, such as bulking the stools, education to avoid bad habits like straining, sitting for long periods of time, etc.
Either system will have a burner. 23 years may very well be beyond the typical life expectancy of a oil burner, but a furnace or boiler should last considerably longer than 23 years. The boiler of my house here in MA is 58 years old and still works fine. I am starting to consider replacements, however.
Parts warranties other then the main burning chamber (heat exchanger) are normally one (1) or five (5) years depending upon the model purchased. Both labor and parts warranties are expired for the Pulse as the last produced units are now over five years. The heat exchanger carried a limited-lifetime warranty.