Trying to sell my house that I bought new 4 years ago. Accepted an offer and the buyers conducted their inspection. Turns out the builder installed the tank less water heater incorrectly. Its been collecting water and is all rusted inside. A second plumber came out and recommended it be replaced ASAP. Its gonna cost me 3 grand to fix this. I PO'd the plumber screwed up, the foreman didn't catch it and the original home inspector didnt say anything. Do I have any recourse after 4 yrs? I don't even know who to ask abt this. Thanks.