It depends on the manufacturer and the terms of the original installation, so this is worth confirming directly rather than assuming either way. Some manufacturer warranties are tied to the original purchaser and don't automatically transfer with the property. Others transfer with the system but require registration or notification within a set period after the sale. Existing homes are generally sold as-is, so a fault appearing after settlement isn't automatically the seller's responsibility unless it was misrepresented at the time of sale.If you've just bought a home with a ducted system, checking the brand, model, and installation date, then contacting the manufacturer directly, is the fastest way to confirm what cover remains.