"The general mood is everyone is tired and everyone wants to go home," said passenger Stuart Rust.
The drama began on Wednesday when the flight was originally supposed to leave Orlando at 8.35pm.
Passengers boarded as normal but around two hours later people reportedly started to faint due to the sweltering heat.
"There were people collapsing," passenger Abigail Kent told the Mirror.
Stuart, 37, a sales manager, from south west London, had just enjoyed a two-week holiday to Disney with his wife and three children aged 20, 12 and eight.
They were informed that the flight would not be leaving that day and instead put in close-by hotels and told to return to the airport the next day.
Stuart says when they boarded the new flight everyone cheered.
But he added: "Some people had a bad feeling. We boarded the plane yesterday. It was due to leave at 6pm some time and it was the same plane and the air con worked fine."
However this wasn't the last of the drama for Stuart and his fellow passengers as the plane was diverted before it could make its planned destination.
"We had three hours of the flight left to go before we landed in Gatwick and you could smell smoke," Stuart said.
Then the holidaymakers were told by the captain that they would be landing at Shannon due to the smell of smoke as a precaution and to expect to be greeted by fire crews and ambulances on arrival.
He added: "We just want to get home and it's dragged it out. It hasn't put a dampener on the holiday but it's left a bitter taste."
Stuart praised the Virgin staff who he said have kept them updated while handing out water and food.
But for Abigail, 28, this is eating up time with her sick mother and she says it has left her feeling "stressed, nauseous and disoriented".
A spokesman for Virgin Atlantic said: "Our flight VS1050 from Orlando to London Gatwick has diverted to Shannon as a precautionary measure after reports of smoke onboard.
"The safety of our customers and crew is always our top priority and we are now working hard to get our customers to their final destination as quickly as possible.
"We'd like to apologise for the disruption to their journey and thank them for their patience."
The extra flight provided by Virgin Atlantic has now left Shannon and will be landing at Gatwick in the next hour or so.