I'm looking at buying a house with a forced air furnace located in the crawlspace. The furnace was checked by a local company and found to have a hole in the heat exchanger. He said that the furnace would have to be replaced and NOT back in the crawlspace because of the presence of a sump pump down there. (Although there are no signs of damage from high water). Is it acceptable (to code) to put in a new one in the crawlspace?