Lennox (NYSE:LII) filed an 8-K on November 2, 2026, announcing that Joe Nassab will transition out of his Executive Vice President and President, Building Climate Solutions role at the end of 2026, and that Geoff Dethlefsen will assume that leadership position effective January 1, 2027.

Key Highlights

  • Leadership transition: Joe Nassab will leave his role as Executive Vice President and President, Building Climate Solutions at the end of 2026 and continue with Lennox as a strategic advisor.
  • Successor named: Geoff Dethlefsen, currently Vice President and General Manager of Lennox Commercial HVAC, will assume leadership of Building Climate Solutions effective January 1, 2027.
  • Nassab's tenure: Nassab joined Lennox in 2010 as Vice President and General Manager of Allied Air and was named to lead the North American Commercial Heating and Cooling segment in 2022, which was later renamed Building Climate Solutions.
  • Dethlefsen's background: Dethlefsen joined Lennox in 2024 with more than 20 years of leadership experience in industrial manufacturing, strategy, and business operations.
  • Prior roles: Before joining Lennox, Dethlefsen served as President of Hammerforce USA and President of Professional Grade Trailers, a division of American Trailer World, and held roles at Flowserve Corporation and Boston Consulting Group.
  • Education: Dethlefsen holds bachelor's degrees in mechanical engineering and Spanish from Rice University and an MBA from The University of Texas at Austin.

Lennox Announces Building Climate Solutions Leadership Change for 2027

According to the filing, Joe Nassab will transition from his position as Executive Vice President and President of Building Climate Solutions at the end of 2026. The company disclosed that Nassab joined Lennox in 2010 and was named to lead the North American Commercial Heating and Cooling segment in 2022, a unit later renamed Building Climate Solutions. During his tenure, the filing states, Nassab helped transform Building Climate Solutions into "a broader commercial equipment and services platform," with the segment expanding through initiatives including the acquisition of AES and investments in manufacturing, distribution, and customer experience.

The company disclosed that Nassab will remain with Lennox in a strategic advisor capacity, focusing on supporting the Building Climate Solutions segment and, according to Chief Executive Officer Alok Maskara as quoted in the filing, "coaching and developing our general managers and the next generation of leaders." Maskara noted that Lennox will "continue to benefit from Joe's leadership and deep industry experience" in his new role.

Geoff Dethlefsen, the named successor, joined Lennox in 2024. The filing states that under Dethlefsen's leadership as Vice President and General Manager of Lennox Commercial HVAC, the unit "has grown in revenue and margins, improved operations, and opened our new manufacturing facility in Saltillo." Dethlefsen's prior experience, as disclosed, includes serving as President of Hammerforce USA and President of Professional Grade Trailers, a division of American Trailer World, as well as leadership roles at Flowserve Corporation and Boston Consulting Group.

What Was Disclosed

Lennox disclosed a planned leadership transition in its Building Climate Solutions segment: Joe Nassab will step down from his executive role at year-end 2026 and move to a strategic advisor position, while Geoff Dethlefsen will take over as Executive Vice President and President of the segment on January 1, 2027.