Answer:
No. An express warranty that is created or stated in a written sales contract does not automatically render all disclaimers invalid. Disclaimers can still be enforceable if they properly address and do not contradict the express warranty, and the contract language shows the disclaimer and the warranty are harmonized. Courts typically apply contract-interpretation rules to resolve conflicts between specific express warranties and general disclaimers, with the specific provisions often taking precedence over general statements. However, disclaimers may be invalid or unenforceable if they contradict an express warranty, are unconscionable, constitute misleading or unfair practices, or run afoul of statutes such as the Magnuson-Moss Warranty Act or applicable consumer protection laws. In practice, a seller should avoid broad general disclaimers that undermine a clearly stated express warranty in the written contract, and should craft disclaimers that (a) are conspicuous, (b) do not negate any express warranties already provided, and (c) comply with applicable law. Key points to consider:

• Express warranties in a written contract often prevail over broad, general disclaimers when there is a conflict between them, especially if the warranty is specific and integrated into the contract. The overall rule is that specific provisions trump general ones in contract interpretation.

• A disclaimer that attempts to negate an express warranty that was formed as part of the contract or that contradicts explicit statements can be deemed invalid or unenforceable. Fraud, misrepresentation, or deceptive-practice arguments can also overturn such a disclaimer.

• The enforceability of a disclaimer may depend on compliance with applicable laws (for example, consumer protection statutes and the Magnuson-Moss Warranty Act) and on whether the disclaimer is conspicuous and properly communicated to the buyer. Disclaimers that run afoul of statutory mandates or that disclaim implied warranties in contexts where such warranties cannot be fully disclaimed (given an express written warranty) may fail.

• The exact outcome can vary by jurisdiction and the specific contract language, so reviewing the written terms and any applicable state or federal warranty statutes is important.

If you want, I can tailor this to your jurisdiction and provide sample clause language that preserves an express warranty while including compliant disclaimers. Note: The above reflects general principles found in contract and warranty law discussions and academic summaries. For precise application, please share the governing jurisdiction and the exact contract language.