I have a lowboy oil furnace circa 1996, I've serviced it fairly regularly, although last year the igniter worked intermittently and I think saturating the mineral insulator with fuel oil several times and lighting it up, was more than that part could take. In cleaning the blower squirrel cage I discovered the hole in the heat exchanger. The distributor is checking with the furnace manufacturer tomorrow, but he said if they still have the part, it'll be $550. I got a price on a new furnace of $4400 installed. Considering that the efficiency of the new furnace is no higher than this one, and my burner was just tuned-up, and my blower is freshly cleaned, what reason, other than a newer cabinet, would I replace this furnace? Now, the tech told me changing the heat exchanger is a pain in the neck job, and would rather do a new install, but how bad could it be?