It depends whether the heating/furnce situation would have been reasonably obvious on a home inspection or when you personally walked through the home before making your offer--and if you had the opportunity to inspect or walk through the home, even if you chose not to take it--or not. The law does not let you recover for relying on another person's representations or statements if the true state of affairs is or should be obvious to you. So if you or an inspector walked through the home, or could have, you almost certainly would have seen there was one furnace, not two, and so you could not legally rely on what the disclosures and realtors said.If you were a relocation from a different area, buying the home under conditions that did not permit you or an agent (e.g. inspector) to view it, then you may be able to sue and recover the cost based on one or more of fraud (if there was a deliberate lie) or promissory estoppel (reasonably relying to your detriment on  a reasonable statement made by others, which statement was made to induce, or as part of inducing, you to enter into the transaction).