So my flight was completely boarded and the doors were shut. They pulled away from The gate We didnt budge. Sat there with No air and a full Plane. told us there was a service issue with a door and they were sending people to check it out. Still Sitting in a plane with little Air in 90 Denver. We had to deboard. Two hours later we Get On another plane and once again sit on a hot air plane for 45 minutes after the new take off time. And you know what? They could care less. User's recommendation: Don’t fly United.