Exhibit 23.1
Consent of Ernst & Young LLP, Independent Registered Public Accounting Firm
We consent to the incorporation by reference in the Registration Statement (Form S-8) pertaining to A. O. Smith Combined Incentive Compensation Plan of our reports dated February 26, 2010, with respect to the consolidated financial statements and schedule of A. O. Smith Corporation and the effectiveness of internal control over financial reporting of A. O. Smith Corporation, included in its Annual Report (Form 10-K) for the year ended December 31, 2009, filed with the Securities and Exchange Commission.
/s/Ernst & Young LLP
Milwaukee, Wisconsin
November 5, 2010
E-4
