Simon Coxell completed climbing 110 floors - the equivalent of 2071 steps - on the on the stairmaster at Phoenix Fitness gym in 27 minutes 34 seconds.
He posted on Facebook: "9/11... 20 years on. Remembering all those that paid the ultimate sacrifice.
"Well done to Crew Manager Coxell for going on another challenge.
"Can't say that was fun, going into a dark place that many never go to when pushing themselves.
"But today was about them, not me
"BIG thanks to those that have donated, BIG thanks to Jack Phoenix for the support and a BIG thanks to Olivia Brown for always fixing me and getting me ready and the family and Michaela for coming and supporting."
Firefighters from around Lincolnshire also paid their tributes who those who died.
Mark Baxter, Chief Fire Officer for Lincolnshire Fire and Rescue, tweeted: "As today marks the 20th anniversary of the tragic events of 9/11, we pay tribute to the 343 firefighters and to the 3,000 lives lost on that day.
"We will pause and reflect for a minutes silence at 13.46. #911Anniversary #LestWeForget"
To make a donation to Simon's 911 tower challenge in aid of the Firefighters' Charity visit www.justgiving.com/fundraising/simon-coxell911towerchallenge