Short answer. No. The general rule makes a seller liable for hidden defects even if unaware of them, but that rule does not apply when the parties expressly agreed there would be no such liability and the seller genuinely did not know about the defect. Both conditions must be true together.

What the law says

The vendor is responsible to the vendee for any hidden faults or defects in the thing sold, even though he was not aware thereof. This provision shall not apply if the contrary has been stipulated, and the vendor was not aware of the hidden faults or defects in the thing sold.

Civil Code, Article 1566 — Vendor Liable Though Unaware. Read the full provision →

The default rule: liability even without knowledge

Ordinarily, a seller answers to the buyer for hidden faults or defects in the thing sold whether or not the seller actually knew about them. The law does not require the buyer to prove the seller was aware of the problem before the sale — the warranty against hidden defects attaches automatically to the sale itself. This protects a buyer who later discovers a defect that neither an ordinary inspection nor the seller's own honest belief about the item would have revealed at the time.

The exception needs two things together

That default rule does not apply, and the seller escapes liability, only where two conditions exist at the same time: the parties expressly stipulated that there would be no warranty for hidden defects, and the seller was in fact unaware of the defect when the sale was made. A waiver clause alone is not enough if the seller actually knew of the flaw and stayed silent; and an unaware seller is not automatically excused if nothing was ever agreed about warranty at all.

What this means for your situation

If your contract genuinely stated that the seller sells without warranty for hidden defects, and the seller can show honest ignorance of the specific defect you found, the seller is released from liability under this provision. But the burden of showing both elements sits with whoever invokes the exception. If the stipulation was vague, or if there is reason to believe the seller knew or should have known of the defect, the general liability rule can still apply, and the waiver will not shield the seller.

Why the law draws the line this way

The rule balances two interests. A buyer who accepts a sale without warranty has consciously taken on the risk of undiscovered flaws, and the seller should not be punished for a defect it never knew existed. But if the exception applied merely because a waiver clause exists on paper, a seller with actual knowledge of a serious flaw could hide behind boilerplate language and never disclose what it knew. Requiring genuine ignorance alongside the stipulation keeps the exception from becoming a shield for concealment, while still letting parties who bargain honestly allocate that risk between themselves.

Cases citing this provision

These Supreme Court decisions cite the provision above. We list them so you can read them yourself; the summaries of what each decided are not ours to give.

Related provisions

Note. Statute text quoted on this page is reproduced from the official enactment and is linked to the full provision. The explanation around it is general legal information from Vivas & Nobles Law Office, not legal advice. Whether it applies to your situation depends on facts only a lawyer reviewing them can assess.