If there's an escrow, does a buyer have to claim from it before going after the seller personally?

It depends entirely on whether the purchase agreement makes the escrow the buyer's exclusive remedy up to its available amount, since that is a drafting choice rather than a default rule. Some agreements expressly state that the escrow is the buyer's "sole and exclusive remedy" for representation and warranty claims up to the escrowed amount, meaning the buyer must draw from the escrow first, and can only pursue the seller personally once the escrow is exhausted or for amounts above it.

Other agreements treat the escrow as simply one available source of recovery among several, leaving the buyer free to pursue the seller directly, the escrow, or both, in whatever order or combination best protects the buyer's interests, without any requirement to exhaust the escrow first. Because these two approaches produce very different practical outcomes for a buyer weighing how to pursue a claim, the "sole and exclusive remedy" language, or its absence, in the specific agreement needs to be checked carefully before assuming either sequencing applies.