Major leak before house closes. Do you have to tell?

Our seller's disclosure technically states "date of purchase to date of filling out this form" but we would highly encourage sellers to make the buyers aware and provide receipts.

In my state they do have to disclose. The fact that they are having the issue repaired shouldn't be a problem with the buyer, but it's the buyers right to know.

If you don't disclose it and the buyer finds out later, they can sue for damages.

This actually happened to us last year! Huge leak in the secondary bathroom a week before closing. We did disclose it, and provided receipts for the repair work done because it was warrantied.

We knew we had a hole in the sewer line under our basement and had 2 quotes to fix it. We told the 3rd guy that we were thinking about selling the house so we wanted to fix the sewer line in advance of that. He told us not to fix it and just hope that it isn't found on inspection which it probably wouldn't be. It wasn't the main sewer line and he said it probably wouldnt be looked at. We were like, what?!?! You want us to lie? He said people do it all the time. If it was found at inspection, feign ignorance and just fix it then.

Needless to say, we went with another company and had it fixed. So yes, I would tell the buyers about it!

I would have to tell for moral reasons. I couldn't live with myself if I didn't.

I agree. Why wouldn't you tell? You're fixing it.
And I think @busyopea is on target. That makes the buyers part of the solution and would go a long way toward helping them feel good about it.

Did your relative make an insurance claim? If so, the buyer's insurance agent (if he/she checked) would be able to see it. Hence, it would look pretty shady if they found out about it later without being told.

Disclosure legalities might vary from state to state. Absolutely I think the seller should disclose the leak to the buyer.